Glossary

Medicaid is a public health coverage program that helps pay for health care and, in many cases, long-term services and supports for eligible people. The exact rules and covered services can vary by state.

A Medicaid waiver is a program that allows a state to offer certain services or use certain rules that differ from standard Medicaid. Waivers are often used for long-term supports, home-based services, and disability-specific service systems.

HCBS stands for home and community-based services. These are services designed to help people receive support in their home or community instead of in an institution or other more restrictive setting.

TEFRA stands for the Tax Equity and Fiscal Responsibility Act of 1982. In the context of Medicaid, it refers to a provision that allows states to make children with significant disabilities eligible for Medicaid based on the child's own income and resources — rather than the family's household income. Not all states use this pathway, and states may label it differently (such as "Katie Beckett" or a specific waiver name).

Level of care is a program standard used to decide how much support a person needs. In Medicaid systems, it often refers to whether the person's needs are serious enough to qualify for certain long-term service programs or waivers.

Eligibility means whether a person meets the rules for a program, benefit, or service. Eligibility can depend on factors such as disability, age, income, resources, level of care, diagnosis, and state rules.

Spend-down is a rule used in some Medicaid-related systems where a person may qualify only after certain income or medical-expense thresholds are met.

Medically necessary usually means a service, treatment, or item is considered needed for diagnosis, treatment, safety, or functioning under the rules of the program or insurer involved.

Prior authorization is approval that may be required before a service, treatment, or piece of equipment will be covered. A request is usually submitted with medical records or other supporting documentation.

An appeal is a request for a decision to be reviewed again after a denial, reduction, or other negative decision. Appeal procedures can vary by state, insurer, and program.

A fair hearing is a more formal review process used in many public-benefit systems, including Medicaid. It is generally different from an informal complaint or phone call and may involve a hearing officer or designated reviewer.

SSI stands for Supplemental Security Income. It is a federal program that provides monthly payments to eligible people who are aged, blind, or disabled and who have limited income and resources.

SSDI stands for Social Security Disability Insurance. It is a federal disability-benefit program tied to work history or certain related benefit structures under Social Security.

Self-direction is a service model that may give the person receiving services, or their family or representative, more control over how certain supports are arranged.

A case manager is a person who helps coordinate services, benefits, referrals, or care planning. The exact role can vary widely by program and agency.

Respite is short-term relief care for a family caregiver or primary support person. It may be offered through Medicaid waivers, state programs, nonprofits, or local agencies.

Durable medical equipment, often called DME, includes medical or adaptive equipment that is meant to be used over time, such as wheelchairs, hospital beds, feeding equipment, or other supportive devices.

IEP stands for Individualized Education Program. It is a written special education plan for an eligible student with a disability and helps guide the student's educational services and supports.

IFSP stands for Individualized Family Service Plan. It is generally used in early intervention for eligible infants and toddlers and focuses on the child's development and family-centered supports.

A 504 plan is a school-based accommodation plan used to help a student with a disability access education. It is different from an IEP and is often used when accommodations or access supports are needed.

An ABLE account is a tax-advantaged savings and investment account for certain people with disabilities. It is designed to help pay for qualified disability expenses while preserving access to many means-tested benefits.

A special needs trust (also called a supplemental needs trust or disability trust) is a legal arrangement that can hold money or property for the benefit of a person with a disability in a way that may help preserve eligibility for certain means-tested benefits. "Special needs trust" is the formal legal term used in federal statute.

A power of attorney (POA) is a legal document in which one person (the principal) authorizes another person (the agent or attorney-in-fact) to make certain decisions on their behalf. A durable power of attorney remains in effect if the principal becomes incapacitated. For disability planning, a financial POA is often used alongside a healthcare proxy to cover both financial and medical decision-making.

A healthcare proxy (also called a healthcare power of attorney or medical power of attorney) is a legal document that designates a trusted person to make medical decisions on someone's behalf if they are unable to communicate or make decisions themselves. It is a less restrictive alternative to guardianship for medical decision-making.

Developmental disability generally refers to a disability that begins during the developmental period and affects major life areas such as learning, mobility, communication, independent living, or other daily functioning.

Autism spectrum disorder is a developmental disability that affects how a person communicates, interacts with others, learns, and experiences the world. It is called a "spectrum" because the combination and severity of traits varies widely from person to person. Under the DSM-5 (the diagnostic manual used by clinicians in the U.S.), an ASD diagnosis includes a support-level specifier of 1, 2, or 3 indicating how much help the person needs. These levels exist so that clinicians, schools, insurers, and service agencies can describe an individual's current support needs in a standardized way — not to rank "how autistic" someone is. A person's level can change over time as skills develop, environments shift, or life demands change. The levels focus on two domains: social communication and restricted/repetitive behaviors.

Level 1 is the mildest specifier. The person can speak in full sentences and may communicate, learn, and live with some independence, but needs support for social communication, organization, flexibility, and navigating unfamiliar situations. Without supports in place, deficits in social communication cause noticeable impairment. The person may have difficulty initiating social interactions, may respond atypically or unsuccessfully to others, and may appear to have reduced interest in social contact. Inflexibility of behavior causes significant interference with functioning in one or more contexts, and the person may have difficulty switching between activities, problems with organization and planning, or trouble working independently.

Level 2 indicates a moderate level of need. The person has marked deficits in verbal and nonverbal social communication skills and noticeable difficulty with social interactions even with supports in place. They may speak in simple sentences, limit interactions to a narrow range of interests, and have reduced or abnormal responses to social overtures. Inflexibility of behavior, difficulty coping with change, or other restricted/repetitive behaviors appear frequently enough to be obvious to a casual observer and interfere with functioning across a variety of contexts. Level 2 support needs go beyond what typical school or community settings provide on their own.

Level 3 is the most severe specifier. The person has severe deficits in verbal and nonverbal social communication skills and very limited initiation of social interactions, responding minimally or only to very direct social approaches from others. Inflexibility of behavior, extreme difficulty coping with change, or other restricted/repetitive behaviors markedly interfere with functioning in all areas. The person generally requires very substantial support across daily life, which may include around-the-clock care, alternative or augmentative communication (AAC), and intensive behavioral, developmental, or therapeutic services.

The three-level system replaced earlier separate diagnoses (such as Asperger's disorder, autistic disorder, and PDD-NOS) that the DSM-5 consolidated under the single umbrella of autism spectrum disorder in 2013. The levels were introduced to provide a common, clinical shorthand for describing an individual's current support needs rather than to categorize a person as "mild," "moderate," or "severe." The intent is practical: to help schools, service agencies, insurers, and families plan appropriate supports. Importantly, the levels describe the level of support needed at the time of assessment — they are not fixed labels, they do not capture the person's full strengths or challenges, and many clinicians caution against using them as the sole basis for eligibility or service decisions.

Down syndrome is a genetic condition caused by an extra copy of chromosome 21 (Trisomy 21). It is the most common chromosomal condition in the U.S. and typically causes intellectual disability ranging from mild to moderate, along with characteristic physical features. Associated health needs may include heart defects (present in about half of babies born with Down syndrome), hearing and vision problems, low muscle tone (hypotonia), thyroid conditions, and a higher risk of sleep apnea and early-onset Alzheimer's. Care needed: early intervention (speech, physical, and occupational therapy starting in infancy), regular cardiac and thyroid screening, vision/hearing checks, and lifelong support with learning, independent living skills, and health monitoring. Many adults with Down syndrome live semi-independently or in supported living arrangements.

Fragile X syndrome is the most common inherited cause of intellectual disability and autism, caused by a mutation in the FMR1 gene on the X chromosome. It affects males more severely than females. Features include intellectual disability (often moderate in males, milder in females), autism-like social and communication challenges, anxiety, attention difficulties, sensory sensitivities, and characteristic physical features (long face, large ears, flexible joints). Care needed: early intervention with speech, occupational, and behavioral therapy; special education supports; treatment for anxiety and ADHD symptoms; and coordination with a developmental pediatrician or geneticist. Many individuals benefit from IEP supports and behavioral therapies such as ABA.

FASD is an umbrella term for conditions caused by prenatal alcohol exposure, the leading preventable cause of intellectual disability and birth defects in the U.S. It is not always inherited but is a developmental disability with a prenatal (environmental) cause. Features can include intellectual disability or learning disabilities, behavioral and emotional regulation difficulties, attention and memory problems, poor impulse control, and sometimes distinctive facial features. Care needed: early diagnosis, special education and IEP/504 supports, behavioral and mental health therapy, social skills training, and often a stable, structured home environment. Affected individuals may need lifelong support with executive functioning and decision-making.

Rett syndrome is a rare genetic neurological disorder caused by mutations in the MECP2 gene, almost exclusively affecting girls. After apparently normal early development (6–18 months), children lose purposeful hand skills and spoken language, develop repetitive hand-wringing movements, and experience slowed head growth, breathing irregularities, seizures, and motor problems. Many eventually need a wheelchair. Care needed: intensive physical, occupational, and speech therapy; seizure management; orthopedic care for scoliosis; assistive communication technology; and around-the-clock care as the condition progresses. Life expectancy is reduced but many individuals live into middle age with comprehensive care.

Phelan-McDermid syndrome (22q13 deletion syndrome) is caused by a deletion or mutation at the end of chromosome 22 and is one of the most common genetic causes of autism. Features include intellectual disability, absent or severely delayed speech, low muscle tone (hypotonia), autism spectrum characteristics, and a tendency toward poor temperature regulation and reduced pain sensation. Care needed: speech and augmentative communication (AAC) therapy, occupational and physical therapy for motor delays, behavioral supports, monitoring for seizures and kidney issues, and special education services tailored to nonverbal learning strengths.

TSC is a genetic disorder caused by mutations in the TSC1 or TSC2 genes that causes non-cancerous tumors to grow in the brain, skin, kidneys, heart, and other organs. About half of people with TSC have autism spectrum disorder, and most have epilepsy and some degree of intellectual disability. Care needed: seizure management (often requiring multiple anti-seizure medications or epilepsy surgery), regular MRI and organ monitoring, developmental and behavioral therapies, special education, and treatment for kidney and cardiac tumors. Lifelong medical surveillance by a multidisciplinary team is typically required.

Prader-Willi syndrome is caused by a deletion or inactivation of genes on the paternal copy of chromosome 15. Babies are typically born with severe low muscle tone and feeding difficulties. In childhood, an insatiable appetite emerges that, without strict management, leads to life-threatening obesity. Features include intellectual disability (usually mild), short stature, behavioral challenges, and obsessive-compulsive tendencies around food. Care needed: early feeding support and growth-hormone therapy, strict environmental food management (locked kitchens, supervised meals), behavioral and mental health care, special education, and lifelong supervised living with food security controls.

Angelman syndrome is caused by a deletion or inactivation of genes on the maternal copy of chromosome 15 (the same region involved in Prader-Willi, but on the other parent's chromosome). Features include severe intellectual disability, absent or very limited speech, seizures, ataxic (unsteady) gait, a happy and excitable demeanor with frequent laughter, and sleep disturbances. Care needed: anti-seizure medication, intensive physical and occupational therapy for mobility, augmentative and alternative communication (AAC), behavioral supports, and lifelong supervision. Most individuals require full-time care throughout life.

Sickle cell disease is an inherited blood disorder caused by a mutation in the HBB gene that produces abnormal hemoglobin, causing red blood cells to become rigid and sickle-shaped. It is the most common inherited disorder detected through U.S. newborn screening and disproportionately affects Black and Hispanic Americans. Features include chronic anemia, episodes of severe pain (pain crises), increased risk of infection, stroke, and organ damage. Care needed: daily medication (penicillin prophylaxis in early childhood, hydroxyurea, and disease-modifying therapies), vaccinations, pain management, regular blood transfusions for some patients, and monitoring for stroke risk. A bone marrow or stem cell transplant can be curative for some children.

Cystic fibrosis is a genetic disorder caused by mutations in the CFTR gene that affects the lungs, pancreas, and other organs, producing thick mucus that leads to chronic lung infections and digestive problems. It is one of the most common life-shortening genetic diseases in the U.S. Features include progressive lung damage, frequent respiratory infections, pancreatic insufficiency causing malnutrition, and infertility in males. Care needed: daily airway clearance therapies, inhaled and oral medications, pancreatic enzyme replacement with every meal, high-calorie nutritional support, and regular care at a CF-accredited center. Modern CFTR modulator drugs have dramatically improved life expectancy for most patients with eligible mutations.

Duchenne muscular dystrophy is a progressive, X-linked recessive neuromuscular disorder caused by mutations in the DMD gene, which prevents the body from producing functional dystrophin — a protein that keeps muscle cells intact. It primarily affects males (about 1 in 3,500 to 5,000 male births) and causes progressive muscle weakness beginning in early childhood, usually between ages 2 and 3. Most boys lose the ability to walk by adolescence and require a wheelchair. Over time, the heart and breathing muscles weaken. Care needed: corticosteroids to slow muscle degeneration, disease-modifying therapies (such as exon-skipping drugs and gene therapy for eligible mutations), cardiac and respiratory monitoring and support, physical and occupational therapy, and multidisciplinary care from neurologists, cardiologists, and pulmonologists. With modern care, many people with DMD now survive into their 30s and 40s.

Spinal muscular atrophy is a genetic neuromuscular disorder caused by mutations in the SMN1 gene, which reduces production of the SMN protein needed for motor neurons to survive. It is the leading genetic cause of infant mortality. SMA has four types: type 0 (most severe, fatal at or shortly after birth), type 1 (onset within six months, the most common and severe form; without treatment, children typically do not survive past age 2), type 2 (onset 6–18 months; children can sit but not walk), and type 3 (milder, onset after 18 months; children can walk). Care needed: early diagnosis (now part of newborn screening in most U.S. states), disease-modifying and gene-replacement therapies that have dramatically improved survival and function, respiratory support, nutritional and feeding support, physical and occupational therapy, and orthopedic care for scoliosis. Types 3 and 4 (adult-onset) typically do not shorten life expectancy.

Neurofibromatosis type 1 is an autosomal dominant genetic disorder caused by mutations in the NF1 gene on chromosome 17, which reduces production of neurofibromin, a tumor-suppressor protein. It occurs in about 1 in 2,500 births. NF1 is a lifelong, progressive condition characterized by café-au-lait (light brown) skin spots, neurofibromas (benign tumors on or under the skin and nerves), freckling in the armpits or groin, and bone abnormalities such as scoliosis. About 40% of affected individuals have learning disabilities or ADHD, and there is an increased lifetime risk of both benign and malignant tumors. Care needed: yearly monitoring of skin, eyes (for optic gliomas), blood pressure, and growth; orthopedic care for scoliosis and bone issues; educational and behavioral supports; and treatment of tumors or complications as they arise. Life expectancy is reduced by an average of about 8 years, mostly due to malignancy and vascular complications.

Williams syndrome (Williams-Beuren syndrome) is caused by a spontaneous deletion of 26–28 genes on one copy of chromosome 7 at position 7q11.23. Features include mild to moderate intellectual disability, a distinctive "cocktail party" social personality (outgoing and overly friendly), cardiovascular problems (often supravalvular aortic stenosis), distinctive facial features, feeding difficulties in infancy, elevated blood calcium, dental and kidney problems, and anxiety. Care needed: early intervention with speech, physical, and occupational therapy; regular cardiovascular monitoring and possible heart surgery; calcium and kidney monitoring; special education and behavioral supports; and, as adults, supportive or supervised housing. Most people with Williams syndrome need lifelong support, and life expectancy can be reduced, primarily due to cardiovascular complications.

Cornelia de Lange syndrome is a rare genetic disorder caused by mutations in one of several genes (most commonly NIPBL, which accounts for about 60–80% of cases) that affect the cohesin complex controlling gene activity during development. Features include intellectual disability ranging from mild to severe, delayed growth and short stature, distinctive facial features, limb differences (such as small hands or missing fingers), excessive body hair, hearing and vision problems, and heart defects. Care needed: early intervention and developmental therapies (speech, occupational, and physical therapy), special education, monitoring and treatment of heart, hearing, vision, and gastrointestinal issues (including reflux), behavioral and mental health supports, and lifelong coordinated care. Severity varies widely, and life expectancy is often reduced in the most severely affected individuals.

Cri du chat syndrome (cat cry syndrome or 5p- syndrome) is a chromosomal disorder caused by a deletion on the short arm (p arm) of chromosome 5. The deletion most often occurs randomly during the formation of reproductive cells or in early fetal development. The hallmark feature is a high-pitched, cat-like cry in newborns, which typically becomes less apparent over time. Other features include low birth weight, weak muscle tone (hypotonia), small head size (microcephaly), distinctive facial features, speech and language delays, moderate to severe intellectual disability, feeding difficulties, scoliosis, and sometimes heart defects. Care needed: early intervention with speech, physical, and occupational therapy; special education; treatment of feeding, hearing, vision, and orthopedic issues; and ongoing developmental support. Most individuals with cri du chat syndrome have a normal life expectancy, though a small number born with serious organ defects may not survive infancy.

Edwards syndrome, or trisomy 18, is a severe chromosomal condition caused by an extra copy of chromosome 18. It is the second most common autosomal trisomy syndrome after Down syndrome, occurring in about 1 in 5,000 live births, and affects females more often than males. Features include severe growth delays before and after birth, low birth weight, congenital heart defects (present in about 90% of cases), clenched hands with overlapping fingers, distinctive facial features, and severe intellectual and developmental disabilities. Most pregnancies with trisomy 18 end in miscarriage or stillbirth. Of live-born infants, about 50–75% survive the first week, 20–40% survive the first month, and 10–19% survive the first year, though intensive interventions can improve survival. Care needed: specialized medical care immediately after birth, cardiac and respiratory support, feeding and nutritional support (often via feeding tube), early intervention, and palliative care planning. Surviving children require lifelong, significant support and most do not learn to walk or talk.

Tay-Sachs disease is a rare, inherited neurodegenerative disorder caused by mutations in the HEXA gene on chromosome 15, which results in a deficiency of the enzyme beta-hexosaminidase A and a toxic buildup of GM2 ganglioside in nerve cells. It is inherited in an autosomal recessive pattern and is more common among people of Ashkenazi Jewish, French-Canadian, and Cajun descent. The most common infantile form appears around 6 months of age with loss of motor skills, seizures, vision and hearing loss, and progressive muscle weakness; affected children typically do not survive past age 4 or 5. Juvenile and late-onset (adult) forms progress more slowly and may not significantly shorten life expectancy. Care needed: there is no cure or disease-modifying treatment; care focuses on symptom management (seizure control, feeding support, airway management, and prevention of complications), physical and occupational therapy, and palliative care for infantile cases. Carrier screening and genetic counseling are available for at-risk families.

Marfan syndrome is an autosomal dominant genetic condition caused by mutations in the FBN1 gene, which produces fibrillin-1, a protein essential for connective tissue. The resulting loose, weak connective tissue affects the heart, blood vessels, bones, joints, and eyes. Features include tall stature with disproportionately long arms and legs, scoliosis, chest wall abnormalities (pectus excavatum or carinatum), joint laxity, severe nearsightedness, lens dislocation (ectopia lentis), and — most critically — enlargement and tearing of the aorta. About 25% of cases arise from a new mutation. Care needed: lifelong cardiac monitoring with echocardiograms, medications (beta-blockers or angiotensin receptor blockers) to protect the aorta, blood pressure management, activity guidelines to avoid aortic stress, regular eye exams, and orthopedic care. With proper cardiovascular management, life expectancy now approaches that of the general population; without treatment, aortic dissection is the leading cause of early death.

Achondroplasia is the most common form of genetic skeletal dysplasia (disproportionate short stature, or dwarfism), caused by a gain-of-function mutation in the FGFR3 gene on chromosome 4. It occurs in about 1 in 25,000 to 30,000 births. Over 97% of cases result from the same missense mutation, which makes the FGFR3 receptor overactive and inhibits bone growth. Features include short limbs (especially the upper arms and thighs), a larger head with a prominent forehead, low muscle tone in infancy, delayed motor milestones, and a normal-sized trunk. Intelligence is typically normal. Care needed: monitoring and treatment of foramen magnum stenosis (which can cause sleep apnea and spinal cord compression), hearing checks, management of spinal stenosis and bowing of the legs, growth-hormone therapy or the newer FGFR3-targeted drug vosoritide to increase growth, and in some cases limb-lengthening surgery. Life expectancy is generally near normal, and most individuals live independently as adults.

Cerebral palsy is a group of lifelong movement disorders caused by abnormal brain development or damage to the developing brain, most often before birth. It is the most common motor disability of childhood. CP affects muscle tone, posture, and movement, and is described by the body parts involved (hemiplegia, diplegia, quadriplegia) and by movement type (spastic, dyskinetic, ataxic, or mixed). It does not worsen over time, though symptoms can change. Many people with CP also have epilepsy, intellectual disability, speech difficulties, vision or hearing impairment, or feeding needs. Care needed: physical, occupational, and speech therapy starting early; orthopedic management (braces, casting, and sometimes surgery for contractures or scoliosis); medications such as baclofen or botulinum toxin for spasticity; seizure treatment; and assistive technology such as wheelchairs or communication devices. Life expectancy varies widely and depends mostly on the severity of movement and associated medical needs.

Epilepsy is a neurological disorder in which a person has recurring, unprovoked seizures — bursts of abnormal electrical activity in the brain. It is diagnosed when a person has at least two unprovoked seizures more than 24 hours apart. Seizures can range from brief lapses in awareness to convulsions. Epilepsy has many causes, including genetic conditions, brain injury, stroke, infections, and structural brain differences, and in about half of cases no cause is found. Care needed: anti-seizure medications (which control seizures in about two-thirds of people), evaluation for epilepsy surgery or devices (such as a vagus nerve stimulator) when medications fail, a seizure action plan and rescue medication, and safety planning around driving, swimming, and supervision. Many people with epilepsy also need support for learning, mental health, or developmental disabilities.

Intellectual disability is a disability characterized by significant limitations in both intellectual functioning (such as learning, reasoning, and problem-solving) and adaptive behavior (everyday social and practical skills), originating before age 22. It is classified as mild, moderate, severe, or profound based on the level of support needed. Causes include genetic conditions (such as Down syndrome and Fragile X), birth complications, infections, brain injury, and environmental factors. Care needed: early intervention, special education and IEP supports, life-skills training, behavioral and mental health services, and lifelong support that ranges from occasional help with complex tasks (mild) to around-the-clock care (profound). Many adults with mild intellectual disability live and work with supports in the community.

Global developmental delay is a term used for children under about age 5 who show significant delays in two or more developmental areas — such as motor, speech and language, social, cognitive, and daily-living skills. It is a descriptive label, not a permanent diagnosis, and is often used before a child is old enough for formal intellectual testing. Care needed: a developmental evaluation to find any underlying cause, early intervention services (speech, occupational, and physical therapy), and ongoing monitoring. Some children outgrow the delays, while others are later diagnosed with an intellectual disability, autism, or a specific genetic or neurological condition.

ADHD is a common neurodevelopmental disorder that begins in childhood and often lasts into adulthood. It involves persistent patterns of inattention, hyperactivity, and/or impulsivity that interfere with functioning or development. There are three presentations: predominantly inattentive, predominantly hyperactive-impulsive, and combined. ADHD frequently co-occurs with learning disabilities, anxiety, autism, and sleep problems. Care needed: behavioral therapy and parent training (especially for young children), educational supports and 504/IEP accommodations, and, when appropriate, stimulant or non-stimulant medication. Many adults with ADHD benefit from coaching, workplace accommodations, and continued treatment.

Hearing loss ranges from mild to profound and may be present at birth (often detected by newborn hearing screening) or acquired later from illness, injury, medications, or aging. It can be conductive (outer/middle ear), sensorineural (inner ear or hearing nerve), or mixed. Language and communication are the main developmental concerns for children, along with social and educational needs. Care needed: early hearing screening and intervention, hearing aids or cochlear implants for eligible children, speech and language therapy, educational supports (IEP/504, sign-language or captioning access), and family support. Deaf children can develop language and learning on a typical timeline with early, appropriate language access, including sign language and/or spoken language.

Vision impairment includes any vision loss that cannot be corrected with standard glasses, contacts, or surgery, ranging from low vision to total blindness. Causes in children include genetic conditions (such as retinopathy of prematurity, albinism, and optic nerve disorders), cortical vision impairment from brain injury, and structural eye problems. Care needed: early intervention including orientation and mobility training, learning braille and assistive technology, educational supports through an IEP/IFSP (often with a teacher of students with visual impairments), and low-vision services. Children with vision impairment can access the same curriculum as peers with the right tools and supports.

Spina bifida is a neural tube defect that occurs when the spine and spinal cord do not form properly during early pregnancy, often linked to low folic acid intake. The most severe and common form, myelomeningocele, causes nerve damage leading to leg weakness or paralysis, loss of bowel and bladder control, and hydrocephalus (fluid buildup in the brain). Care needed: surgery to close the spinal opening shortly after birth, a shunt to manage hydrocephalus, mobility aids and orthopedic care, bladder and bowel management programs (often including catheterization), and educational supports. With modern care, most people with spina bifida live into adulthood, and many use wheelchairs or braces for mobility.

Osteogenesis imperfecta (OI) is a group of genetic disorders caused most often by mutations in the COL1A1 or COL1A2 genes, which affect collagen production and result in bones that break easily, sometimes with little or no apparent cause. There are several types ranging from mild to severe. Features can include frequent fractures, short stature, blue-tinted sclera (whites of the eyes), hearing loss beginning in young adulthood, loose joints, and, in severe forms, respiratory problems. Care needed: fracture care and prevention, bisphosphonate medications to strengthen bones, orthopedic surgery including rodding of long bones, physical therapy, and hearing monitoring. Life expectancy is near normal in mild forms and may be shortened in the most severe types.

Ehlers-Danlos syndrome is a group of inherited connective tissue disorders, most commonly the hypermobile type, that affect collagen and result in loose, stretchy skin and over-flexible (hypermobile) joints. Features include frequent joint dislocations and pain, chronic fatigue, easy bruising, digestive and autonomic problems (such as POTS), and fragile tissues. The vascular type is rarer but more serious, with risk of organ or blood vessel rupture. Care needed: physical therapy focused on joint stabilization and pain management, bracing, cardiology monitoring (especially in vascular type), pain management, and pacing strategies. Many people with EDS need activity accommodations and lifelong management of joint and tissue complications.

Turner syndrome affects females and is caused when one X chromosome is missing or structurally altered (45,X or mosaicism). It occurs in about 1 in 2,500 live female births. Features include short stature, ovarian failure that leads to lack of puberty and infertility (in most cases), webbed neck, low hairline, heart and kidney differences (such as coarctation of the aorta), and a higher risk of learning difficulties in math and spatial reasoning and social challenges. Intelligence is typically normal. Care needed: growth-hormone therapy in childhood, estrogen replacement to induce puberty and protect bones, regular cardiac and kidney monitoring, and educational and psychosocial support. With proper management, life expectancy is generally near normal, though ongoing heart monitoring is important.

Klinefelter syndrome affects males and is caused by an extra X chromosome (47,XXY), occurring in about 1 in 500 to 1,000 male births. Many cases are mild or diagnosed in adulthood. Features include small testes and low testosterone leading to infertility, taller stature, gynecomastia, and a higher risk of learning (especially language) and social difficulties, anxiety, and certain medical conditions such as osteoporosis and diabetes. Care needed: testosterone replacement therapy usually beginning in adolescence, fertility evaluation, educational and speech-language supports, and monitoring of bone, metabolic, and cardiovascular health. Most men with Klinefelter syndrome live typical lifespans with treatment and support.

22q11.2 deletion syndrome (also called DiGeorge syndrome or velocardiofacial syndrome) is caused by a deletion of a small piece of chromosome 22 and is one of the most common genetic deletion syndromes, occurring in about 1 in 4,000 births. Features vary widely but often include heart defects, immune system differences, cleft palate, low calcium levels, characteristic facial features, learning disabilities, and a higher risk of psychiatric conditions such as schizophrenia in adulthood. Care needed: early cardiac surgery or monitoring, immune evaluation, calcium monitoring, speech and palate assessment, developmental and educational supports, and mental health surveillance over the lifespan. Care is coordinated across multiple specialists.

Patau syndrome, or trisomy 13, is a severe chromosomal condition caused by an extra copy of chromosome 13, occurring in about 1 in 10,000 live births. Features include severe intellectual disability, heart defects, brain and facial differences (such as holoprosencephaly and cleft lip/palate), extra fingers or toes, eye defects, and other organ problems. Most pregnancies with trisomy 13 end in miscarriage or stillbirth. Of live-born infants, about 80–90% do not survive the first year, though some with mosaic or partial forms and intensive care live longer. Care needed: specialized medical care immediately after birth, cardiac and respiratory support, feeding support, early intervention, and palliative care planning. Surviving children need lifelong, significant support.

Phenylketonuria is an inherited metabolic disorder caused by mutations in the PAH gene that prevent the body from breaking down the amino acid phenylalanine. It is detected through U.S. newborn screening. Without treatment, phenylalanine builds up and causes severe intellectual disability, seizures, and behavior problems. Care needed: a strict, lifelong low-phenylalanine diet (low in protein, with a special medical formula), regular blood monitoring, and a medication (sapropterin) that helps some patients process phenylalanine. When the diet is followed from infancy, children with PKU have normal intelligence and development. Current guidelines recommend the diet be continued for life — stopping it in adulthood can affect attention, mood, and thinking.

Hemophilia is a group of inherited bleeding disorders in which the blood does not clot properly because of low levels of clotting factor. Hemophilia A (factor VIII deficiency) and hemophilia B (factor IX deficiency) are X-linked and primarily affect males, while hemophilia C (factor XI deficiency) is milder. Severity depends on factor levels. Features include prolonged bleeding after injury, surgery, or dental work, and spontaneous bleeding into joints and muscles that can cause pain and joint damage. Care needed: regular infusions of clotting factor (prophylaxis), on-demand factor treatment for bleeding episodes, physical therapy to protect joints, and dental and surgical coordination with a hemophilia treatment center. With modern treatment, life expectancy is near normal.

Becker muscular dystrophy is a milder, X-linked recessive variant of dystrophin-related muscular dystrophy, caused by mutations in the DMD gene that produce some reduced or partially functional dystrophin. It primarily affects males. Symptoms usually begin in later childhood or adolescence and progress more slowly than in Duchenne. Features include progressive weakness of the hips, pelvis, and legs, calf enlargement, and, over time, heart and breathing muscle involvement. Care needed: physical and occupational therapy, cardiac and respiratory monitoring (heart involvement can occur even with mild muscle weakness), disease-modifying therapies for eligible mutations, bracing and mobility aids, and surgery for scoliosis or contractures as needed. Many people with BMD walk into adulthood and have a variable life expectancy that depends on cardiac and respiratory care.

Myotonic dystrophy is the most common form of adult-onset muscular dystrophy, caused by an autosomal dominant repeat expansion in the DMPK gene (type 1) or CNBP gene (type 2). It causes progressive muscle weakness and myotonia (difficulty relaxing muscles after contraction), along with cataracts, heart rhythm problems, daytime sleepiness, digestive issues, and, in the congenital form of type 1, severe weakness and developmental disability in newborns. Care needed: cardiac monitoring (pacemakers may be needed for arrhythmia), respiratory support, physical and occupational therapy, cataract treatment, and management of sleep and digestive symptoms. The congenital form requires intensive early intervention and lifelong support; adult-onset forms progress slowly but shorten life expectancy, mostly through cardiac complications.

Charcot-Marie-Tooth disease is a group of inherited peripheral nerve disorders (the most common inherited neuromuscular disorder) that cause progressive muscle weakness and loss of sensation, primarily in the feet, lower legs, and hands. Symptoms often begin in adolescence or early adulthood and include foot drop, high arches, frequent tripping, loss of fine hand control, and reduced reflexes. Care needed: physical and occupational therapy, orthotics and ankle-foot orthoses (AFOs) to support walking, orthopedic surgery for foot or joint deformities, and pain management. CMT progresses slowly and does not usually shorten life expectancy, though it can lead to significant mobility and dexterity limitations over time.

Friedreich's ataxia is an inherited, progressive neurodegenerative disorder caused by a repeat expansion in the FXN gene that reduces frataxin, a protein important for cellular energy. It is autosomal recessive and usually begins between ages 5 and 15. Features include progressive difficulty walking (ataxia) from loss of coordination, muscle weakness, loss of sensation, scoliosis, heart disease (cardiomyopathy), and diabetes. Most people eventually need a wheelchair. Care needed: physical and occupational therapy, cardiac monitoring and treatment, diabetes management, orthopedic care for scoliosis, and the recently approved drug omaveloxolone, which can slow progression. Life expectancy is reduced, often into mid-adulthood, mainly due to heart disease.

Tourette syndrome is a neurodevelopmental disorder characterized by multiple motor tics and one or more vocal tics that begin before age 18 and last for at least a year. Tics are sudden, brief, repetitive movements or sounds. Many people with Tourette syndrome also have ADHD, OCD, anxiety, or learning disabilities. Care needed: education and support, behavioral therapy (such as habit-reversal training), and medication when tics cause pain, impairment, or distress. Most children's tics improve or resolve by late adolescence, though some continue into adulthood, often with less severity than in childhood.

Huntington's disease is an autosomal dominant, progressive brain disorder caused by a CAG repeat expansion in the HTT gene that leads to degeneration of nerve cells in the brain. Symptoms usually begin between ages 30 and 50 with movement problems (chorea — involuntary jerking movements), cognitive decline, and psychiatric changes such as depression and irritability. Juvenile-onset forms progress more quickly. Care needed: there is no cure, so care focuses on managing movement symptoms with medications, psychiatric and behavioral support, speech and swallowing therapy, physical and occupational therapy, and eventually full-time care as the disease progresses. Life expectancy after symptom onset is typically 15 to 20 years. Genetic testing and counseling are available for at-risk family members.

Multiple sclerosis is an autoimmune disease in which the immune system attacks the protective covering (myelin) of nerve fibers in the brain and spinal cord, disrupting communication between the brain and body. It is more common in women and usually begins between ages 20 and 50. Symptoms vary widely and can include fatigue, vision problems, weakness, numbness, balance and walking difficulty, and cognitive changes. Most people have a relapsing-remitting course, though it can become progressive over time. Care needed: disease-modifying therapies that reduce relapses and slow progression, symptom management (medications, physical and occupational therapy), and supports for fatigue, mobility, and employment. MS rarely shortens life expectancy, but it can cause significant disability over time.

Dyslexia is a specific learning disability that is neurobiological in origin and primarily affects accurate and fluent word reading and spelling. It results from differences in how the brain processes language sounds (phonological processing), not from low intelligence or poor vision. Features include slow, effortful reading, difficulty sounding out words, poor spelling, and reading below expected level. Care needed: structured literacy instruction (explicit, systematic phonics such as Orton-Gillingham approaches), classroom accommodations (extra time, assistive technology, audiobooks), and an IEP or 504 plan. With appropriate support, people with dyslexia become capable readers and succeed academically and professionally.

Developmental coordination disorder, often called dyspraxia, is a neurodevelopmental condition that affects the planning and coordination of movement. It is not caused by low muscle tone, a known neurological condition, or general intellectual disability. Features include clumsiness, difficulty with fine and gross motor tasks (handwriting, tying shoes, catching a ball, riding a bike), trouble with organization, and sometimes speech and sensory differences. Care needed: occupational therapy for motor skill development, handwriting support and assistive technology, physical education accommodations, and an IEP/504 plan. The condition often continues into adulthood, but most people adapt with strategies and supports.

Cleft lip and cleft palate are among the most common birth defects, occurring when a baby's lip or the roof of the mouth (palate) does not form completely during early pregnancy. They can occur together or separately and may be part of a genetic syndrome. Feeding and hearing are the main early concerns. Care needed: special feeding bottles and techniques, surgery to repair the lip (usually by 3–6 months) and palate (usually by 9–18 months), hearing evaluation and sometimes ear tubes, speech therapy, orthodontic and dental care, and, for some, psychological support and additional surgeries through childhood. With coordinated care, most children have good outcomes and typical life expectancy.

Microcephaly is a condition in which a baby's head is much smaller than expected, often because the brain did not develop properly during pregnancy or stopped growing after birth. Causes include genetic conditions, infections during pregnancy (such as Zika or cytomegalovirus), exposure to alcohol or certain drugs, and problems with blood or oxygen supply. Effects range from mild to severe and can include intellectual disability, developmental delays, seizures, feeding problems, hearing and vision loss, and movement problems. Care needed: early intervention, developmental and seizure monitoring, feeding and therapy supports, and coordination among specialists. Outcomes depend heavily on the cause and severity, and severe microcephaly can shorten life expectancy.

Hydrocephalus is a buildup of cerebrospinal fluid in the brain that causes pressure and can damage brain tissue. It may be present at birth (often with spina bifida) or develop later from bleeding, infection, tumors, or injury. In infants, it can cause rapid head growth; in older children and adults it can cause headaches, vomiting, vision changes, balance problems, and developmental or cognitive decline. Care needed: a surgical shunt or an endoscopic third ventriculostomy to drain or redirect the fluid, lifelong monitoring of shunt function, and developmental and educational supports. With treatment, many people with hydrocephalus live typical lifespans, though shunt problems require prompt medical attention.

Childhood apraxia of speech is a motor speech disorder in which the brain has difficulty planning and coordinating the precise movements needed for speech, even though the muscles themselves are not weak. Children with apraxia know what they want to say but struggle to produce sounds, syllables, and words consistently. It often co-occurs with other speech, language, or fine-motor challenges. Care needed: intensive, frequent speech therapy with a therapist trained in apraxia, practice with motor-planning approaches, AAC if needed while speech develops, and an IEP/IFSP. With early, appropriate therapy, many children make significant progress and become effective communicators.

Noonan syndrome is a genetic condition caused by changes in genes of the RAS-MAPK pathway (most often PTPN11) that affects many areas of the body. It occurs in about 1 in 1,000 to 2,500 births. Common features include short stature (in about 50%–70% of individuals), congenital heart defects (most often pulmonary valve stenosis), easy bruising or bleeding, and characteristic facial features. Intelligence is usually normal, though learning difficulties are common. Care needed: growth-hormone therapy (an FDA-approved use), cardiac monitoring and treatment of heart defects, bleeding-precaution planning before surgery, hearing and vision checks, and educational supports for learning challenges. Life expectancy is generally near normal with proper management.

CHARGE syndrome is a genetic condition caused most often by mutations in the CHD7 gene. The name comes from its hallmark features: coloboma (a gap in the eye structure), heart defects, atresia of the choanae (blocked nasal passages), growth and developmental delays, genital abnormalities, and ear anomalies with deafness. (Older sources expand the "R" as "retardation of growth and/or development" — an outdated term now written as growth and developmental delays.) Newborns often have life-threatening breathing and feeding problems from choanal atresia. Most cases are the first in the family. Care needed: early surgery for choanal atresia and heart defects, hearing and vision assessment and intervention, feeding and airway support, developmental therapies, and lifelong coordinated care across many specialties.

Kabuki syndrome is a rare genetic disorder caused most often by mutations in the KMT2D gene (about 75% of cases) or the KDM6A gene. It is named for the resemblance of affected children's facial features to Kabuki theater makeup. Features include mild to moderate intellectual disability, low muscle tone, distinctive facial features, heart defects, cleft palate, immune deficiencies, and feeding problems in infancy. Care needed: early intervention and developmental therapies, cardiac monitoring and surgery as needed, immune evaluation, hearing and vision checks, and educational supports. Most cases are new (de novo) mutations, and life expectancy is generally near normal with proper care.

Smith-Magenis syndrome is a developmental disorder caused most often by a deletion on chromosome 17 (17p11.2) that includes the RAI1 gene. Features include mild to moderate intellectual disability, delayed speech, distinctive facial features, and a characteristic pattern of sleep disturbance in which the body's melatonin rhythm is inverted, causing trouble falling asleep, frequent night waking, and excessive daytime sleepiness. Behavioral challenges can include impulsivity, anxiety, and self-injurious behaviors such as skin picking or head banging. Care needed: melatonin supplements and careful sleep management, behavioral and mental health supports, speech and educational therapies, and a structured environment. Life expectancy is expected to be normal.

Sanfilippo syndrome, or mucopolysaccharidosis type III, is an inherited lysosomal storage disorder caused by a deficiency in one of four enzymes (including SGSH) needed to break down certain sugars. It is autosomal recessive and primarily affects the brain and spinal cord. Children often develop normally for the first few years, then show severe behavioral problems, sleep disturbance, hyperactivity, and progressive loss of speech, skills, and mobility (developmental regression). Seizures and movement problems appear later. Physical features are milder than in other mucopolysaccharidoses. Care needed: behavioral and sleep management, seizure treatment, feeding and airway support, physical therapy, and palliative care planning. Life expectancy is shortened, with most individuals living into adolescence or early to mid-adulthood; there is no cure, though treatments are under investigation.

Sturge-Weber syndrome is a rare neurocutaneous disorder caused by a somatic (after-conception) mutation in the GNAQ gene. It is characterized by a facial port-wine birthmark (a flat, pink-to-purple capillary malformation, usually on the forehead and upper face), a leptomeningeal angioma (abnormal blood vessels on the surface of the brain), and glaucoma. The brain involvement causes seizures in most affected individuals, along with stroke-like episodes, weakness on one side of the body (hemiparesis), and possible intellectual disability. Care needed: seizure medications and sometimes epilepsy surgery, glaucoma treatment (eye drops or surgery), low-dose aspirin to reduce stroke-like episodes, and developmental and educational supports. Severity varies widely.

Neurofibromatosis type 2 is an autosomal dominant disorder caused by mutations in the NF2 gene, which makes a tumor-suppressor protein called merlin. It is much less common than NF1. The hallmark is the growth of benign tumors on nerves, especially vestibular schwannomas (also called acoustic neuromas) on the hearing and balance nerves, typically affecting both ears and causing progressive hearing loss, tinnitus, and balance problems. People with NF2 also develop meningiomas, ependymomas, and schwannomas on other nerves. Care needed: regular MRI monitoring, hearing evaluations, surgery or stereotactic radiosurgery for growing tumors, hearing rehabilitation (hearing aids, cochlear or auditory brainstem implants), and surveillance for skin and eye tumors. Symptoms often begin in the teens or twenties. Life expectancy is reduced, mainly from tumor complications.

Hurler syndrome is the most severe form of mucopolysaccharidosis type I, an inherited lysosomal storage disorder caused by a deficiency of the enzyme alpha-L-iduronidase (the IDUA gene). It is autosomal recessive. Features appear in the first year of life and include coarse facial features, clouding of the corneas, umbilical and inguinal hernias, an enlarged liver and spleen, heart disease, stiff joints, and progressive intellectual disability. Without treatment, children often do not survive past about age 10. Care needed: hematopoietic stem cell (bone marrow) transplantation in early infancy to preserve brain function, lifelong enzyme replacement therapy (laronidase) for non-brain symptoms, cardiac and airway management, orthopedic care, and developmental support. Milder forms of MPS I are called Hurler-Scheie and Scheie syndromes.

Classic galactosemia is an inherited metabolic disorder caused by mutations in the GALT gene that prevent the body from breaking down the sugar galactose (found in milk). It is detected through U.S. newborn screening. Without treatment, babies develop life-threatening liver failure, bleeding, jaundice, and E. coli infection within days of starting milk feedings. Care needed: immediate and lifelong removal of lactose and galactose from the diet (soy formula in infancy; avoiding all dairy and hidden galactose for life), and monitoring for cataracts, speech delays, learning disabilities, and (in females) premature ovarian insufficiency. Even with strict early treatment, some long-term issues can still occur. With prompt dietary treatment, most children survive the newborn period and develop with varying degrees of support.

Sotos syndrome is an overgrowth disorder usually caused by mutations or deletions in the NSD1 gene. Children grow faster than peers during early childhood with an advanced bone age and a large head (macrocephaly); adult height often normalizes. Features include mild intellectual disability or learning difficulties, low muscle tone, delayed motor development, characteristic facial features, and a high rate of autism spectrum features. Care needed: developmental and educational supports (IEP), speech and occupational therapy, behavioral supports, and monitoring for scoliosis, seizures, and heart or kidney issues. Sotos syndrome is not life-threatening, and life expectancy is generally normal.

Russell-Silver syndrome is a growth disorder usually caused by loss of methylation at the 11p15 imprinting region or, less often, by maternal uniparental disomy of chromosome 7. It is characterized by intrauterine growth restriction (small at birth) and poor growth after birth, with a relatively large head, a triangular face, a prominent forehead, feeding difficulties, and body asymmetry (one side or limb smaller than the other). Intelligence is typically normal. Care needed: feeding support and, if needed, a feeding tube in early childhood, growth-hormone therapy, monitoring for fasting hypoglycemia, and developmental support. With treatment, most children improve their growth and have a normal life expectancy.

Beckwith-Wiedemann syndrome is an overgrowth disorder caused by changes in gene regulation on chromosome 11p15. Features include excessive growth before and after birth (macrosomia), a large tongue (macroglossia), abdominal wall defects such as omphalocele, and low blood sugar in the newborn period from too much insulin. Affected children have a higher risk of childhood tumors, especially Wilms tumor (kidney) and hepatoblastoma (liver). Care needed: treating neonatal hypoglycemia, surgery for abdominal wall defects or macroglossia when needed, and a strict tumor-surveillance program (abdominal ultrasound and blood tests such as alpha-fetoprotein every three months through early childhood). Most children do well with proper monitoring.

VACTERL association is a non-random grouping of birth defects that occur together more often than by chance. The acronym stands for Vertebral defects, Anal atresia, Cardiac defects, Tracheo-Esophageal fistula (with esophageal atresia), Renal anomalies, and Limb abnormalities. A diagnosis generally requires at least three of these features. Most cases are sporadic with no family history, and boys are slightly more often affected. Care needed: multiple surgeries in infancy (often for the tracheoesophageal fistula, anal atresia, and heart defects), kidney monitoring, and orthopedic care for limb or spine differences. Intelligence is usually normal. Care is coordinated across surgery, urology, cardiology, and orthopedics.

Dravet syndrome (severe myoclonic epilepsy of infancy) is a rare epileptic encephalopathy caused most often by mutations in the SCN1A gene. Seizures usually begin in the first year of life, often as prolonged febrile seizures, and become frequent, multiple-type, and hard to control. Children often lose skills and develop intellectual disability, autism features, and walking and balance problems over time. Care needed: carefully chosen anti-seizure medications (avoiding sodium-channel blockers such as lamotrigine, which can worsen seizures), add-on therapies such as stiripentol, fenfluramine, and pharmaceutical cannabidiol (Epidiolex), a ketogenic diet in some cases, a seizure action plan and rescue medication, and developmental and educational supports.

Infantile spasms, also called West syndrome, is a severe epilepsy syndrome of early infancy. Brief, sudden spasms (sudden stiffening or jackknife movements) usually begin between 4 and 9 months of age, often in clusters, especially as the child falls asleep or wakes. The EEG shows a chaotic pattern called hypsarrhythmia, and most children have developmental delay or regression. Causes include brain injury, genetic conditions (such as tuberous sclerosis), and metabolic disorders. Care needed: prompt treatment with adrenocorticotropic hormone (ACTH), oral steroids, or vigabatrin (especially when caused by tuberous sclerosis), the ketogenic diet if medications fail, and early intervention. Many children go on to have other seizure types and developmental disabilities; early treatment improves outcomes.

Lennox-Gastaut syndrome is a severe, lifelong developmental epileptic encephalopathy that begins in childhood. It is defined by multiple seizure types (especially tonic, atonic "drop" seizures, and atypical absence seizures), a characteristic EEG pattern of slow spike-and-waves, and intellectual disability or developmental delay. Seizures are usually hard to control. Care needed: anti-seizure medications such as clobazam, rufinamide, and felbamate, the ketogenic diet, and, for some, corpus callosotomy (surgery to reduce drop seizures) or neurostimulation devices; a seizure and injury-prevention plan; and lifelong developmental, educational, and daily-living supports. Many children transition into adult care with continuing needs.

Wolf-Hirschhorn syndrome is a chromosomal disorder caused by a deletion on the short arm of chromosome 4 (4p16.3). It occurs in roughly 1 in 20,000 to 50,000 births. Features include a characteristic facial appearance often described as a "Greek warrior helmet" (broad nasal bridge and high forehead), growth delay, intellectual disability, low muscle tone, and seizures (which affect most children and can be hard to control early on but often improve with age). Midline defects such as cleft lip and palate can occur. Care needed: seizure management, feeding and growth support, developmental and educational therapies, and treatment of heart, urinary, and skeletal problems. About one third of children have serious health problems in the first years; those who survive infancy typically have slow but steady development.

Mitochondrial diseases are a group of inherited disorders in which the mitochondria (the energy-producing parts of cells) do not work properly. They can be caused by mutations in mitochondrial DNA (passed from the mother) or in nuclear DNA (inherited from both parents). Because every organ needs energy, mitochondrial disease can affect almost any organ at any age — most often the brain, muscles, heart, eyes, ears, and digestive system. Features can include developmental delay or regression, seizures, muscle weakness, exercise intolerance, hearing and vision loss, heart problems, and diabetes. Care needed: evaluation by a specialist team, metabolic and genetic testing (sometimes including muscle biopsy), symptom management (seizure, cardiac, and respiratory care), "mito cocktail" vitamin and supplement regimens when recommended, and avoidance of medications that can stress mitochondria. Severity and life expectancy vary widely; severe childhood forms (such as Leigh syndrome) can be life-shortening.

Juvenile idiopathic arthritis is the most common chronic rheumatic disease of childhood. It is diagnosed when a child under 16 has arthritis in one or more joints for at least six weeks with no other known cause. There are several subtypes; oligoarticular JIA (four or fewer joints) is the most common and often affects young girls. Features include joint swelling, stiffness (especially in the morning), pain, and reduced movement; systemic JIA also causes fever and rash. Children with oligoarticular JIA, especially those positive for ANA antibodies, are at high risk for uveitis (eye inflammation), which can cause permanent vision loss if untreated. Care needed: regular eye exams, disease-modifying medications (such as methotrexate and biologics like etanercept), physical and occupational therapy, and joint injections. With modern treatment, most children have greatly improved outcomes.

Selective mutism is a childhood anxiety disorder in which a child who can speak comfortably in some situations (usually at home) is consistently unable to speak in other settings (such as school or with strangers). It is not defiance, shyness, or a speech delay. It usually becomes noticeable around ages 3 to 5, often when a child starts preschool or school. Care needed: evaluation by a pediatric and mental health professional, behavioral therapy (cognitive behavioral therapy and "stepladder" exposure approaches), school-based supports and accommodations, and, for moderate-to-severe cases, medication such as an SSRI. With early, consistent treatment, most children improve significantly, though some continue to experience social anxiety.

Hypoxic ischemic encephalopathy is brain injury in a newborn caused by a lack of oxygen and blood flow around the time of birth. It can lead to neonatal encephalopathy (abnormal brain function), seizures, feeding and breathing problems, and long-term disability including cerebral palsy, intellectual disability, epilepsy, and developmental delays. The severity varies. Care needed: the only proven treatment is therapeutic hypothermia (cooling the baby to about 33.5°C) started within six hours of birth and continued for 72 hours for term and near-term infants with moderate-to-severe HIE, plus seizure treatment, supportive intensive care, and brain MRI for prognosis. Babies who receive cooling are followed closely for developmental and neurologic outcomes and referred to early intervention as needed.

Periventricular leukomalacia is a form of brain injury that affects the white matter near the fluid-filled spaces (ventricles) in the brain. It is the leading known cause of cerebral palsy in premature infants, especially those born before 32 weeks. It happens when the immature white matter is injured by poor blood flow and inflammation. Features can include spastic diplegia (stiffness mainly in the legs), cerebral palsy, developmental delays, vision problems, and sometimes seizures; mild cases may cause only cognitive or learning difficulties. Care needed: diagnosis by cranial ultrasound or MRI, physical, occupational, and speech therapy, management of spasticity and seizures, and early intervention and educational supports. Outcomes depend on the extent of injury.

McCune-Albright syndrome is a rare disorder caused by a somatic (after-conception) activating mutation in the GNAS gene, so it is not inherited and affects the body in a patchy (mosaic) pattern. The classic triad is polyostotic fibrous dysplasia (weak, scar-like bone in many bones, often on one side), café-au-lait skin spots with jagged ("coast of Maine") borders, and endocrine overactivity — most commonly precocious (early) puberty, especially in girls, but also overactive thyroid, growth-hormone excess, and other hormone issues. Care needed: endocrinology management of hormone overproduction, orthopedic care and monitoring for fractures and bone lesions, dental and skin care, and management of hearing and vision problems if the skull is affected. Severity varies widely depending on which tissues carry the mutation.

WAGR syndrome is a contiguous gene deletion syndrome caused by a deletion on chromosome 11p13 that includes the WT1 and PAX6 genes. The name stands for Wilms tumor (a childhood kidney cancer), Aniridia (absence of the iris of the eye), Genitourinary anomalies, and a Range of developmental delays (intellectual disability). Children with WAGR have about a 45%–60% chance of developing Wilms tumor. Care needed: regular Wilms tumor surveillance with abdominal ultrasound and kidney function tests from diagnosis through childhood, eye exams and vision support, evaluation and management of kidney and genital abnormalities, and developmental and educational supports. Lifelong coordinated care is needed, and outcomes depend on early tumor detection and management.

Dandy-Walker syndrome (Dandy-Walker malformation) is a congenital brain malformation involving underdevelopment (hypoplasia) or absence of the cerebellar vermis (the middle part of the cerebellum that controls coordination), a cyst-like enlargement of the fourth ventricle, and an enlarged posterior fossa. Most affected infants develop hydrocephalus (fluid buildup in the brain) by three months of age. Features can include an enlarged head, vomiting, irritability, delayed motor development, low muscle tone, poor coordination (ataxia), seizures, and intellectual disability of varying degree; milder forms have fewer deficits. Care needed: a shunt or other surgery to treat hydrocephalus, seizure management, and developmental, physical, and occupational therapy. Outcomes vary widely from normal function to severe disability depending on the severity and any associated brain differences.

Holoprosencephaly is a brain malformation in which the forebrain does not divide into two hemispheres during early development. It ranges from alobar (most severe, no separation) through semilobar to lobar (mildest). It is often associated with the SHH (sonic hedgehog) gene pathway and other genetic or environmental causes. Features include midline facial differences (such as cleft lip and palate, closely set eyes, or, in the most severe cases, a single eye), seizures, developmental delay (which is universal), feeding problems, and hormonal problems. Severe alobar forms are often fatal in infancy; lobar forms can have near-normal intelligence. Care needed: anti-seizure medication, surgery for cleft lip and palate, feeding support, hormone management, and early intervention. Prognosis depends heavily on the severity and associated medical problems.

Landau-Kleffner syndrome (acquired epileptic aphasia) is a rare childhood epilepsy syndrome in which a child who previously developed language normally loses the ability to understand and speak words, usually between ages 3 and 8. It is associated with epileptic activity on the EEG, most often continuous spike-wave discharges during sleep (electrical status epilepticus of sleep, or ESES), even though the child may have few or no obvious seizures. Care needed: anti-seizure medication (corticosteroids are often effective, sometimes with clobazam or other drugs), speech and language therapy, educational and behavioral supports, and, in selected cases, multiple subpial transection surgery. Language recovery varies; outcomes are better with early recognition and treatment.

Hunter syndrome, or mucopolysaccharidosis type II, is an inherited lysosomal storage disorder caused by deficiency of the enzyme iduronate-2-sulfatase (the IDS gene). It is X-linked and almost always affects males. Features include coarse facial features, enlarged liver and spleen, joint stiffness, hernias, heart and airway problems, and progressive intellectual disability in the severe form; unlike Hurler syndrome, the corneas are usually not clouded. Care needed: lifelong enzyme replacement therapy (idursulfase), cardiac and airway management, orthopedic and neurologic care, and developmental support; bone marrow transplant is not generally used. Severe forms shorten life expectancy, mainly from heart and airway complications; milder forms allow longer survival with treatment.

MECP2 duplication syndrome is an X-linked neurodevelopmental disorder that almost exclusively affects males and is caused by an extra copy of the MECP2 gene on the X chromosome. (The same gene, when mutated rather than duplicated, causes Rett syndrome in girls.) Features include severe intellectual disability, low muscle tone in infancy that progresses to spasticity (stiffness), delayed or absent speech, seizures that can be hard to control, feeding and digestive problems, and frequent respiratory infections that can be life-threatening. Female carriers are usually unaffected or mildly affected. Care needed: seizure management, physical and occupational therapy, speech therapy (often with AAC), treatment of infections, and developmental and educational supports. Life expectancy is reduced, most often due to recurrent infections and respiratory failure.

Pallister-Killian syndrome is a rare chromosomal disorder caused by a mosaic extra isochromosome 12p (i(12p)), meaning some cells have an extra piece of the short arm of chromosome 12. Features include very weak muscle tone (hypotonia) in infancy, severe to profound intellectual disability, developmental delay, a distinctive "coarse" facial appearance, sparse hair (especially at the temples), streaks or patches of unusual skin coloring, seizures, and sometimes hearing loss, vision problems, extra nipples, and heart defects. Care needed: feeding and breathing support in infancy, seizure management, hearing and vision evaluation, physical and occupational therapy, and developmental and educational supports. The severity varies, and life expectancy can be reduced in the most severely affected.

CDKL5 deficiency disorder is a rare developmental epileptic encephalopathy caused by mutations in the X-linked CDKL5 gene, affecting girls much more often than boys. Seizures usually begin within the first weeks or months of life (often before 3 months) and are typically multiple-type and hard to control, sometimes with a temporary "honeymoon" quiet period. Other features include low muscle tone, severe developmental delay, cortical visual impairment, and sleep and feeding problems. Care needed: careful seizure management (often multiple medications, plus treatments such as ganaxolone or cannabidiol when appropriate), early intervention, vision assessment, feeding and GI support, and lifelong daily-living supports.

Dup15q syndrome is a chromosomal duplication syndrome caused by extra copies of chromosome 15 (typically the 15q11.2-q13 region), most often maternal. It is a leading single-gene-region cause of autism. Features include low muscle tone, motor delays, moderate to severe intellectual disability, autism spectrum disorder, seizures (often starting in infancy, sometimes infantile spasms), and a characteristic gait with arms held up. Sleep and anxiety problems are common. Care needed: seizure and infantile-spasms management, early intervention, behavioral and educational supports, and ongoing monitoring. Seizures can be hard to control in some children; care is coordinated across neurology, developmental services, and therapies.

Potocki-Lupski syndrome is a chromosomal duplication syndrome caused by an extra copy of part of chromosome 17 (17p11.2), involving the RAI1 gene — the mirror image of Smith-Magenis syndrome, which involves a deletion of the same region. Features include low muscle tone, failure to thrive and feeding problems in infancy, delayed development with speech delay, congenital heart defects, sleep problems, and autism spectrum behaviors. Intelligence ranges from normal to mild intellectual disability. Care needed: cardiac evaluation, feeding support and growth monitoring, sleep evaluation, speech and developmental therapies, and educational supports. Most children do well with supports.

Jacobsen syndrome is a chromosomal disorder caused by a deletion on the long arm of chromosome 11 (11q). It occurs in roughly 1 in 100,000 births. Features include delayed development, intellectual disability (usually mild to moderate), distinctive facial features, Paris-Trousseau thrombocytopenia (a mild bleeding disorder from low platelets), congenital heart defects, feeding difficulties, and recurrent infections. Care needed: heart evaluation and surgery when needed, blood and bleeding precautions, growth and feeding support, developmental therapies, and educational supports. Many individuals live into adulthood with supports.

Koolen-de Vries syndrome is a genetic condition caused by a deletion at 17q21.31 or mutations in the KANSL1 gene. Features include low muscle tone from birth, developmental delay with speech delay, mild to moderate intellectual disability, a friendly, amiable personality, characteristic facial features, and sometimes seizures, heart, kidney, or urogenital problems. Care needed: early intervention and developmental therapies, speech therapy, seizure monitoring, and educational supports. Most individuals have mild-to-moderate intellectual disability and a generally stable, positive outlook with supports.

Pitt-Hopkins syndrome is a rare neurodevelopmental disorder caused by mutations in the TCF4 gene. It is characterized by moderate to severe intellectual disability, delayed development, a wide mouth and distinctive facial features, and abnormal breathing episodes (hyperventilation or breath-holding, often triggered by excitement or anxiety), which can be dangerous. Seizures, constipation, and behavioral features resembling autism are common. Care needed: breathing-pattern monitoring and treatment, seizure management, speech therapy with AAC, feeding support, and behavioral and educational supports. Many cases are new (de novo) mutations.

Mowat-Wilson syndrome is a rare genetic disorder caused by de novo mutations in the ZEB2 gene. It is characterized by distinctive facial features (including uplifted earlobes), moderate to severe intellectual disability, severe speech impairment, and seizures (in about three quarters of individuals). Hirschsprung disease (a blockage of the bowel from missing nerve cells, requiring surgery) occurs in nearly half, along with congenital heart defects, genital anomalies, microcephaly, and chronic constipation. Care needed: bowel surgery and GI management if Hirschsprung disease is present, seizure control, cardiac follow-up, feeding support, and lifelong developmental and educational care.

Rubinstein-Taybi syndrome is a genetic disorder caused most often by mutations in the CREBBP gene (in most studied cases) or the EP300 gene. It is characterized by broad, short thumbs and big toes, short stature, distinctive facial features, and intellectual disability that ranges from mild to severe. Individuals are at increased risk of tumors (especially brain tumors) in childhood, along with heart defects, feeding problems, and sleep difficulties. Care needed: early developmental therapies, monitoring for childhood tumors, cardiac evaluation, dental care, and educational and behavioral supports. Intelligence is usually in the mild-to-moderate range, and many individuals live well into adulthood.

Smith-Lemli-Opitz syndrome is an inherited metabolic disorder caused by mutations in the DHCR7 gene, which makes the last enzyme in the body's cholesterol-making pathway. People with SLOS have low cholesterol and a build-up of a toxic precursor called 7-dehydrocholesterol. Features range widely and can include distinctive facial features, microcephaly, intellectual disability or learning problems, autism-like behaviors, second-toe/third-toe syndactyly (webbing), genital anomalies, and growth issues. Care needed: cholesterol supplementation and careful monitoring of sterol levels, feeding support, developmental and educational therapies, and treatment of associated organ issues. Severity ranges from mild learning problems to severe multi-organ disease.

Joubert syndrome is a group of rare ciliopathy disorders (affecting the hair-like cilia that help cells signal) that affect the cerebellum and brainstem, producing a distinctive "molar tooth sign" on brain imaging. It is usually autosomal recessive and can involve many different genes. Features include developmental delay, intellectual disability, breathing abnormalities (rapid breathing or apnea in infancy), low muscle tone, poor coordination (ataxia), eye movement problems, and sometimes kidney, liver, and retinal disease. Care needed: monitoring of breathing in infancy, evaluation of kidneys, liver, and vision, physical and occupational therapy, and early intervention. Severity varies widely.

Bardet-Biedl syndrome is a rare genetic ciliopathy (usually autosomal recessive) that affects many body systems. Features include retinal dystrophy leading to progressive vision loss and blindness, early-onset obesity, extra fingers or toes (polydactyly), kidney problems, intellectual disability or learning difficulties, hypogonadism, and increased risk of type 2 diabetes. Care needed: regular vision monitoring and blindness-preparation services, kidney monitoring, weight management and treatment of diabetes, sleep apnea screening, and developmental supports. There is no cure, though treatments are being studied.

Alström syndrome is an extremely rare autosomal recessive disorder caused by mutations in the ALMS1 gene. Features typically begin in infancy and include progressive cone-rod retinal dystrophy leading to blindness, progressive sensorineural hearing loss, childhood obesity, insulin resistance, and type 2 diabetes. Dilated cardiomyopathy (heart muscle disease) occurs in about 70% of patients during infancy or adolescence, and liver and kidney problems develop over time. Care needed: cardiac monitoring and treatment, vision and hearing services, weight and diabetes management, and kidney and liver surveillance. Life expectancy is often reduced, primarily from heart, liver, or kidney complications.

Alagille syndrome is an autosomal dominant multisystem disorder caused by mutations in the JAG1 gene (about 94% of cases) or the NOTCH2 gene. It affects the liver (paucity of small bile ducts leading to cholestasis and severe itching), heart (especially branch pulmonary artery stenosis), skeleton (butterfly-shaped vertebrae), eyes, kidneys, and blood vessels, with distinctive facial features. Care needed: liver monitoring, treatment of cholestasis and itching, cardiac evaluation and surgery when needed, and liver transplantation in severe cases. Many individuals do well, though some need lifelong liver care.

Costello syndrome is a rare overgrowth disorder caused by mutations in the HRAS gene on the Ras/MAPK pathway. Features include intellectual disability, distinctive facial features, loose skin with deep creases on the hands and feet, heart defects and rhythm problems, high risk of certain benign and malignant tumors (especially papillomas and rhabdomyosarcoma), failure to thrive in infancy, and short stature. Care needed: cardiac monitoring including arrhythmia management, regular tumor screening, feeding and growth support, orthopedic care, and lifelong developmental and educational supports.

Cardio-facio-cutaneous (CFC) syndrome is a rare genetic disorder caused by mutations in genes of the Ras/MAPK pathway — most often BRAF, or MEK1, MEK2, or KRAS. Features include congenital heart defects (especially atrial and ventricular septal defects), distinctive facial features, sparse curly hair and dry skin, low muscle tone, feeding difficulties, and intellectual disability ranging from mild to severe. Care needed: cardiac monitoring and treatment, feeding and growth support, skin and hair care, and lifelong developmental, speech, and educational therapies. Related Ras/MAPK conditions include Noonan, Costello, and LEOPARD syndromes.

Coffin-Siris syndrome is a rare genetic disorder most often caused by mutations in the ARID1B gene (or other SWI/SNF-complex genes). It is characterized by intellectual disability (mild to severe), low muscle tone, developmental delay (especially speech), coarse facial features with sparse scalp hair, and underdeveloped or absent fingernails or toenails (usually the fifth finger). Care needed: early intervention and therapies, speech support (often AAC), seizure monitoring, feeding support, and educational supports. Most individuals have moderate intellectual disability and live into adulthood with supports.

Schaaf-Yang syndrome is a rare genetic disorder caused by mutations in the MAGEL2 gene on chromosome 15 — the same gene region affected in Prader-Willi syndrome, which is why it is sometimes called a "Prader-Willi-like" syndrome. Features include intellectual disability, autism spectrum disorder, joint contractures (stiffness) at birth, low muscle tone, feeding difficulties in infancy, sleep problems, behavioral challenges, and sometimes heart or gastrointestinal issues. Care needed: feeding support in infancy, developmental therapies, behavioral and educational supports, and monitoring for sleep and other medical issues.

Gorlin syndrome (nevoid basal cell carcinoma syndrome) is an autosomal dominant disorder caused by mutations in the PTCH1 gene. It is characterized by multiple basal cell skin cancers, benign jaw cysts (keratocysts), small pits on the palms and soles, distinctive facial features, enlarged head size, and a small increased risk of medulloblastoma (a childhood brain tumor) and ovarian fibromas. Care needed: regular skin checks and sun protection, jaw X-rays and dental monitoring, radiation avoidance when possible (people with Gorlin are very radiation-sensitive), and monitoring for childhood brain tumors. With careful surveillance, most people live normal lifespans.

Stickler syndrome is a group of autosomal dominant collagen disorders (most often the COL2A1 gene, or COL11A1, COL11A2, or COL9 genes) that affect the eyes, ears, joints, and face. Features include severe nearsightedness (myopia) with a high risk of retinal detachment that can cause blindness, cataracts, hearing loss, cleft palate and Pierre Robin sequence (small jaw and tongue causing airway and feeding problems), and joint problems with early-onset arthritis. Care needed: frequent retinal exams and preventive laser treatment to reduce detachment risk, hearing evaluation, palate or airway surgery in infancy, speech therapy, and orthopedic care. With preventive eye care, most people have good outcomes.

Incontinentia pigmenti is an X-linked dominant disorder caused by mutations in the IKBKG (NEMO) gene. It almost always affects females, because it is usually lethal in males before birth. It progresses through four skin stages (blisters, warty growths, swirling dark pigment, then pale streaks) and can also affect the teeth (missing teeth), eyes (retinal disease that can cause blindness), brain (seizures, strokes), and other organs. Care needed: careful skin care, regular eye exams with early treatment of retinal disease to prevent vision loss, seizure management if needed, and dental care. Most females with the condition have good vision and normal intelligence when eye and brain complications are managed.

Alport syndrome is a genetic disorder of type IV collagen (most often X-linked from mutations in the COL4A5 gene, or autosomal from COL4A3/COL4A4) that damages the kidneys, inner ears, and eyes. It causes blood in the urine (hematuria) from childhood, progressive kidney failure (often in adolescence or young adulthood in males), sensorineural hearing loss, and eye abnormalities such as misshapen lenses. Care needed: early ACE-inhibitor treatment to slow kidney decline, hearing monitoring, regular kidney function checks, and kidney transplant or dialysis when the kidneys fail. Early treatment can significantly delay kidney failure and improve life expectancy.

Fabry disease is an X-linked lysosomal storage disorder caused by mutations in the GLA gene, which makes the enzyme alpha-galactosidase A. Without it, a fatty substance builds up in blood vessels, kidneys, heart, skin, and nerves. Symptoms often begin in childhood: burning pain in hands and feet (acroparesthesia), heat intolerance, small red-purple skin spots (angiokeratomas), and decreased sweating. Over time, it causes kidney failure, heart disease, and strokes, usually in adulthood. Care needed: enzyme replacement therapy or oral chaperone therapy (migalastat, for eligible mutations), pain management, and lifelong monitoring of heart and kidneys. Carrier females can also develop symptoms.

Gaucher disease is the most common lysosomal storage disorder, an autosomal recessive condition caused by mutations in the GBA gene, which makes the enzyme glucocerebrosidase. Without it, fatty material accumulates in organs. Type 1 (most common) causes enlarged spleen and liver, anemia, low platelets, and bone pain or fractures, with normal intelligence; types 2 and 3 also affect the brain. Care needed: lifelong enzyme replacement therapy (imiglucerase, velaglucerase, or taliglucerase) for type 1 and type 3, bone monitoring, and supportive care. With treatment, many people with type 1 live full, active lives; neuronopathic types are more severe.

Niemann-Pick type C (NPC) is a rare autosomal recessive lysosomal storage disorder caused by mutations in the NPC1 gene (95% of cases) or NPC2 gene, which disrupt how cells move cholesterol and fats around. Symptoms vary by age but include abnormal vertical eye movements (a hallmark sign), poor coordination (ataxia), swallowing and speech problems, seizures, gelastic cataplexy (sudden falls when laughing), intellectual decline, and psychiatric symptoms. Care needed: miglustat to slow neurological progression, swallowing and feeding support, seizure and movement management, and multidisciplinary care. The disease is progressive and life-limiting, so careful coordinated care is essential.

Krabbe disease (globoid cell leukodystrophy) is an autosomal recessive leukodystrophy caused by deficiency of the enzyme galactocerebrosidase (GALC gene), which destroys myelin, the protective coating on nerves. The infantile form begins in the first months of life with irritability, stiff limbs, extreme sensitivity to touch, feeding problems, rapid regression, and usually death in early childhood without treatment. Later-onset forms are milder and progress slowly. Care needed: hematopoietic stem cell (umbilical cord blood) transplant, ideally before symptoms appear, which can significantly change outcomes; newborn screening (now in some U.S. states) and rapid referral are critical. Symptom management and family support are ongoing needs.

Metachromatic leukodystrophy (MLD) is an autosomal recessive lysosomal storage disorder caused by deficiency of the enzyme arylsulfatase A (ARSA gene), which leads to a build-up of sulfatides that damages myelin in the brain and nerves. The late-infantile form (most common) begins around 1–2 years with gait problems and regression, progressing to loss of speech, movement, and swallowing; juvenile and adult forms progress more slowly. Care needed: when identified presymptomatically (via newborn or family screening), hematopoietic stem cell transplant or the gene therapy atidarsagene autotemcel (Lenmeldy) can dramatically alter the course; otherwise, care focuses on symptom management, nutrition, and comfort. Early diagnosis is essential.

Batten disease refers to a group of more than a dozen inherited neurodegenerative lysosomal storage disorders (the neuronal ceroid lipofuscinoses, CLN genes). The most common childhood form, CLN3 juvenile Batten disease, begins with vision loss between ages 4 and 8, followed by school difficulties, seizures, movement and speech problems, and progressive loss of skills. Most people with CLN3 disease live into early adulthood. Care needed: vision and blindness services, seizure management, physical and occupational therapy, feeding support as skills decline, and coordinated palliative and supportive care; enzyme-replacement or gene therapies exist for some rarer forms (such as CLN2) when given early.

X-linked adrenoleukodystrophy is the most common peroxisomal disorder, caused by mutations in the ABCD1 gene, which lead to a build-up of very long-chain fatty acids that damage the adrenal glands, brain, and spinal cord. It affects mainly males, with several forms: adrenal insufficiency (dangerously low stress hormones), a rapidly progressive childhood cerebral form (in about 35%–40% of males, typically ages 3–10), and a slowly progressive adult spinal cord form (adrenomyeloneuropathy). Care needed: lifelong adrenal hormone monitoring and replacement (this is life-saving), newborn screening (added to the U.S. recommended panel in 2016), regular brain MRI monitoring, hematopoietic stem cell transplant to halt early cerebral disease, and dietary oil therapy (Lorenzo's oil) alongside monitoring. Females can develop milder adult-onset symptoms.

Juvenile dermatomyositis (JDM) is the most common childhood inflammatory muscle disease — an autoimmune, small-vessel condition that causes muscle inflammation and a characteristic rash. Features include symmetrical proximal muscle weakness (trouble climbing stairs, getting up from the floor), a purplish rash on the eyelids (heliotrope rash), scaly red-purple bumps over knuckles, elbows, and knees (Gottron papules), fatigue, and sometimes calcium deposits in the skin (calcinosis), gut or lung involvement, and joint inflammation. Care needed: rheumatology care with immunosuppressive medications (corticosteroids, methotrexate, and biologics), physical and occupational therapy to restore strength, sun protection, and monitoring for calcinosis and organ involvement. With modern treatment, most children improve significantly, though relapses and lifelong monitoring are common.

Beta thalassemia major (Cooley's anemia) is an inherited blood disorder in which the body makes little or no working adult hemoglobin, causing severe anemia beginning in the first year or two of life. It is treated with lifelong regular red-blood-cell transfusions (every few weeks), which in turn cause iron overload that damages the heart, liver, and endocrine organs without iron-chelation medication. Other complications include an enlarged spleen, bone changes, growth delay, and hormone problems. Care needed: lifelong transfusion schedule and iron chelation therapy, monitoring for heart, liver, and hormone complications, splenectomy when needed, and (in selected patients) bone marrow transplant or gene therapy (ZYNTEGLO, CASGEVY). With proper treatment, survival to older adulthood is now expected.