Disease/Disorder
Definition
Down Syndrome (DS), also known as Trisomy 21, is the most common chromosomal genetic syndrome and the most common pattern of human malformation and cause of moderate intellectual disability. It is named after John Langdon Down, who described the syndrome in 1866. Down syndrome is characterized by a variety of dysmorphic features, congenital malformations and systemic complications but not all of them are present in each affected individual.1
Etiology2
| Cause | % | Relation to maternal age | Misc. | |
| Trisomy 21 | Nondisjunction during meiosis produces extra chromosome in gamete | 95% | May be present | All cells in the body are affected. |
| Translocation | Transfer of chromosomal material from one chromosome to another in carrier | 3% | Usually not seen | Carriers are phenotypically normal but have increased risk of having chromosomally abnormal offspring and miscarriages. |
| Mosaicism | Two different cell lines are derived from a single zygote | 2% | May be present | Cognitive impairments are variable due to variable presentation. |
Epidemiology including risk factors and primary prevention
DS occurs approximately once in 700 live births in the United States. Compared to national prevalence estimates for many birth defects, prevalence of DS has increased across a 15-year period from 1999 to 2010.3 DS is the most common cause of miscarriage and is found in all ethnic groups and economic classes. Advanced maternal age exponentially increases the chances of having a child with DS: 0.1% in a 20-year-old woman, 1% in a 40-year-old, and >3.5% in a 45-year-old woman. Other risk factors include having a previous child with DS (1%) or another chromosomal abnormality, parental balanced translocation, and parents with chromosomal disorders. There is no evidence identifying hormones, toxins, drugs, viruses, or vitamin deficiencies as causes of DS.
Patho-anatomy/physiology1
DS may be understood best as a syndrome complex of genetic and epigenetic origin with several characteristic neurodevelopmental manifestations. The majority of cases result from complete trisomy of chromosome 21 due to random nondisjunction during meiosis. A region on chromosome 21 proximal to 21q22.3, known as the Down syndrome critical region, is considered responsible for pathogenesis of DS. In approximately 87% of cases of trisomy 21, the nondisjunction is of maternal origin. Rarely, in about 2% of cases, nondisjunction may occur after fertilization is complete, resulting in two different cell lines referred to as mosaicism. Persons with mosaicism may be more mildly affected than complete trisomy 21 or with translocation but may have indistinguishable medical complications. Approximately 3% of the time, DS results from complete or partial translocation of chromosome 21 to another chromosome. This so called Robertsonian translocation occurs when the long arms of two acrocentric chromosomes fuse at the centromere, resulting in the loss of the two short arms. There is ongoing research on how different areas of chromosome 21 influence the phenotypic manifestation of DS.
Disease progression including natural history, disease phases or stages, disease trajectory (clinical features and presentation over time)
DS is usually detected by prenatal screening, hypotonia at birth, and clinical features. Global developmental delay is the usual presentation. Initial hypotonia improves to close to normal tone with time. Life expectancy has improved from 25 in 1983 to 60 years, due to a decline in infant and child mortality and improved cardiovascular care. Intellectual quotient (IQ) ranges from 30 to 70; with the majority of individuals with DS having mild to moderate intellectual disability. There is increased risk of early onset dementia which is the leading cause of death in adults with DS. Other common causes of death include leukemia, respiratory illnesses, congenital circulatory defects, diseases of the digestive system, Alzheimer’s disease, and epilepsy. Severity of cognitive impairment is a good predictor of ability to live independently.
Specific secondary or associated conditions and complications4
| System | Abnormalities |
| Cardiac | Septal defects (atrioventricular > ventricular > atrial), patent ductus arteriosus, tetralogy of Fallot, pulmonary hypertension, aberrant subclavian artery, mitral valve prolapse, tricuspid valve prolapse, aortic regurgitation. |
| Pulmonary | Recurrent lower respiratory tract infections, tracheomalacia, chronic rhinitis, pulmonary aspiration, sleep disordered breathing. |
| Endocrine | Hypothyroidism, short stature, obesity, type I diabetes, hypogonadism, infertility. |
| Hematological | Acute lymphoblastic leukemia, acute myeloid leukemia, antiphospholipid antibodies, deep vein thrombosis (DVT). |
| Oral/Gastrointestinal | Duodenal atresia, esophageal atresia, annular pancreas, Hirschsprung’s disease, celiac disease, constipation, gastroesophageal reflux, periodontal disease and gingivitis5 |
| Orthopedic/ Musculoskeletal | Scoliosis, pes planus, patellofemoral instability, single transverse palmar crease, enlarged space between first and second toes, short 5th digit with clinodactyly; atlantoaxial instability, recurrent joint dislocation including hip dysplasia,6 arthropathy of Down syndrome, joint hypermobility, slipped capital femoral epiphysis. |
| Neurologic | Seizures, hearing loss, developmental delay, Moyamoya disease. |
| Ophthalmologic | Refractive errors, cataracts, strabismus, myopia. |
| Psychiatric | Depression, autism spectrum disorders, attention deficit hyperactivity disorder, intellectual disability. |
| Immunologic | Innate and adaptive abnormality, increased risk of infection, high mortality from sepsis. |
Essentials of Assessment
History
| Maternal | How old were you when you had your child? Did you have any previous miscarriages? Did any of your previous children have any genetic conditions? Is there a family history of any developmental or chromosomal conditions? |
| Newborn | Did the child cry at birth? Was the child blue? Did the child need to be intubated and placed on a ventilator? Did the child pass meconium within 48 hours of birth? Were there any feeding problems? Did the child need intravenous nutrition: glucose or calcium? Was it difficult to hold the child? Did it feel like the child slipped through the parents’ hands? |
| Child/ Adolescent | What specific motor, language, social, and cognitive milestones has your child reached? Has the muscle tone changed from low tone to normal tone or high tone? Is there a change in gait pattern or any difficulty with balance? Is there a history of new onset torticollis? Are there changes in bowel and bladder function? Does your child snore or breathe loudly at night, causing any difficulties with sleep? |
| Adults/ Older | How is your memory? Do you have problems remembering things of late? Have you had any vision problems? How do you get around? What are your goals and what do you enjoy doing? |
Prenatal screening and diagnostic testing7
- Screening in any trimester: Analysis of cell-free fetal DNA in maternal plasma is the most sensitive and specific screening test for the common fetal aneuploidies. Cell-free DNA fragments are detectable in maternal circulation starting at 9-10 weeks of gestation until term.
- First-trimester (10-14 weeks of gestation): Serum analytes plus ultrasound – Measurement of nuchal translucency (NT) through ultrasound, Pregnancy-associated plasma protein A (PAPP-A), free or total beta human chorionic gonadotrophin (hCG), and alpha-fetoprotein (AFP).
- Second trimester (15-22 weeks of gestation): Quadruple marker screening – maternal serum AFP, hCG, unconjugated estriol, and dimeric inhibin A.
- Ultrasound can also evaluate for potential structural markers for DS including nonvisualized nasal bone, tricuspid regurgitation, crown-rump length, femur and humeral length.
- In patients with a positive analyte or cell-free DNA screen in the setting of abnormal fetal sonographic findings, there is concern for a chromosomal abnormality. Chorionic villus sampling (CVS) or amniocentesis is recommended to confirm the diagnosis and to determine if the aneuploidy is due to a trisomy or translocation.
Physical examination8,9
| System | Physical features |
| HEENT | Brachycephaly, midface hypoplasia, flattened nasal bridge, hypoplastic frontal sinuses, hypertelorism; blocked tear ducts; short neck, small mouth, oral hypotonia, fissured tongue, geographic tongue, delayed dental eruption, hypodontia; low set ears, hearing loss, otitis media |
| Ophthalmic | Brushfield spots in iris, lens opacities, refractive errors, nystagmus, strabismus, amblyopia, cataracts, palpebral fissures narrow with outer part slanted upward, epicanthal folds, keratoconus |
| Cardiac/Respiratory | Endocardial cushion defects with murmur, signs of pneumonia |
| Gastrointestinal/ Genitourinary | Imperforate anus, duodenal atresia, hypospadias, cryptorchidism |
| Growth/Development | Overall delay in gross motor skills, fine motor skills and in language development, short stature, obesity |
| Neurologic | Hypotonia, poor moro reflex, regular documentation of DTRs and Babinski reflexes to pick up change related to myelopathy or cerebrovascular disease (Moya-Moya) |
| Orthopedic | Short broad hands, incurved fifth finger with hypoplastic mid phalanx, transverse palmar crease, space between the first and second toes, hyperflexible joints |
| Psychiatric | Behavioral problems: impulsivity, poor judgment, short attention span, slow learning, poor coordination |
| Cutaneous | Hyperkeratosis, seborrhea, xerosis, perigenital folliculitis, cutis marmorata, alopecia areata |
Functional assessment
Functional assessment includes a detailed history and physical examination aimed at evaluating phenotypic characteristics, muscle tone, and deficits in balance and postural control, which all have implications in achieving developmental milestones. Motor performance can be monitored in individuals with DS using the following scales – Alberta Infant Motor Scale, Test of Infant Motor Performance, Bayley, Peabody Gross Motor Scale, or Pediatric Evaluation of Disability Inventory.10 Language assessment and cognitive evaluation may reveal dysphonia and articulation problems and intellectual delay, which can affect socialization and school placement.
Laboratory studies11
If results of prenatal testing are not available, a sample of cord or peripheral blood should be obtained for postnatal karyotype to confirm the diagnosis if the clinician is concerned for DS.
General health and prevention screening recommended for patients with Down syndrome includes
- Thyroid function tests at birth, 6 and 12 months of age, and annually thereafter to monitor for acquired thyroid disease.
- Complete blood count (CBC) with differential: to monitor for leukemia and/or anemia at birth, annually, or any visit if concerns for easy bruising or bleeding, recurrent fevers, or bone pain.
- Ferritin, serum iron, and total iron binding capacity (TIBC): to screen for iron deficiency anemia at age 1 year and annually thereafter.
Imaging6,11,12,13
- For myelopathic signs or symptoms, including significant neck pain, radicular pain, weakness, spasticity, hyperreflexia, and/or change in bowel and bladder, obtain radiographs of the cervical spine in neutral position and refer to a pediatric neurosurgeon or an orthopedic surgeon promptly if abnormal. If neutral radiograph is normal, flexion and extension radiographs may be obtained before considering referral to a surgeon but routine screening radiographs for potential atlantoaxial instability in asymptomatic children are no longer recommended. Cerebral arterial occlusion (Moya-Moya disease) can be an alternative explanation for upper motor neuron signs and requires brain MRI/MRA and prompt referral for revascularization as well. Education on signs and symptoms of atlantoaxial instability and sports/activities with increased risk of spinal cord injury should be provided to caregivers, such as positioning for surgeries/anesthesia, trampoline use, etc.
- Echocardiogram prior to discharge from the hospital at birth or before 1 month.
- Feeding assessment if marked hypotonia, slow feeding, failure to thrive, or any signs of difficulty swallowing by first year.
- Consider hip radiographs for surveillance of hip dysplasia – early in childhood, taking into consideration ambulatory status and overall tone. There are currently no formal guidelines, unlike hip surveillance in cerebral palsy, but this may change in the future. Both nonsurgical and surgical options for treatment of hip dysplasia exist, similar to hip dysplasia in other populations, although it is less studied in DS.
Supplemental assessment tools11
- Screening antibodies of tissue transglutaminase and total IgA to evaluate for celiac disease at 2 years of age or with symptoms.
- Audiology screening at birth and 6 months. If normal hearing established, behavioral audiogram and tympanometry until bilateral ear specific testing is possible.
- Sleep study to evaluate for obstructive sleep apnea by 4 years.
- Eye exam for cataracts between birth to 1 month, and ophthalmological referral to assess for strabismus, cataracts and nystagmus between 6 months to 1 year. and 1 month to 1 year.
- Psychiatric monitoring and education to address depression, autism, anxiety, attention deficit hyperactivity disorder (ADHD).
- Referral to a dentist.5,10
- Recurrence risk counseling for families.
Early predictions of outcomes
Mosaicism is associated with a better functional outcome.1,8,11 Cognitive ability and health are likely related to an individual’s ability to live independently.1 High-functioning adults with DS may be able to live with minimal assistance in the community. Presence of lower IQ may be associated with being placed in sheltered workshops. Infants with very low birth weight and DS, African American infants with DS, and infants with DS who also had a congenital heart defect have higher rates of mortality than those without.2
Environmental
- Cognition should be assessed for appropriate placement in schools.
- Familial environment should be assessed for extent of involvement and understanding of their child’s condition and capability to make available appropriate interventions.
- School services should be assessed as well, to ensure appropriateness.
Social role and social support system
- Success at school is dependent upon having an Individualized Educational Program (IEP) in place.
- Atlantoaxial instability places children with DS at risk and should be identified prior to allowing participation in recreational activities. Special Olympics has screening requirements for all athletes for participation in sports.
- Families and siblings should be provided with information regarding local support groups.
- Employment is important for adults with DS who may be able to live independently, but job opportunities can be limited by bias.12
Professional issues
- Diagnostic tests are associated with risks that create moral and ethical quandaries.
- The costs involved in the care of individuals with disabilities make care challenging.
- Plastic surgery for cosmetic purposes is a controversial topic.
- Prenatal genetic counselling, due to recurrence risk (based on maternal age and parental translocation), provides information to families regarding future pregnancies.
Rehabilitation Management and Treatments
Available or current treatment guidelines
Management of DS is focused on treating comorbidities and associated complications, not curative. The reader is referred to the health supervision guidelines per American Academy of Pediatrics regarding various screening and referrals as necessary.11
Early childhood intervention programs and outpatient therapies may be necessary, depending on individual need. School-based therapies address only educationally relevant goals and are utilized to ensure community integration. Short courses of intensive outpatient therapy can be used to address specific changes in overall functional status.
A structured cardiovascular conditioning program is needed due to the associated obesity, secondary to poor eating habits, sedentary lifestyles, poor opportunities for recreational activities, and poor coordination and motivation.
At different disease stages
| Age | Intervention |
| Infancy | Refer to early childhood intervention to focus on developmental therapies. Audiological and ophthalmological/neuro-optometric evaluation. Swallow evaluation. Monitor growth parameters (failure to thrive). Sensory integration and vestibular stimulation could be included in therapies. |
| Early/Late childhood | Refer to outpatient therapies, including physical, occupational and speech therapies. Joint laxity with pes planus may benefit from supramalleolar orthoses or foot orthoses to help improve cadence and step length. 14 Knee-ankle-foot orthosis for patellofemoral instability may be helpful. Orthoses do not cure joint laxity or promote early ambulation. C-spine instability evaluation/monitoring. Sleep study for evaluation and monitoring of obstructive sleep apnea. Referral to support systems is important at every stage. |
| Adolescence | Obesity monitoring: assess family lifestyle, eating habits, level of physical activity. Establish optimal dietary and physical exercise regimen. Monitoring of sleep apnea and its treatment. Gynecological care should be set up in prepubescent females. May need wheelchair assessment. Vocational rehabilitation evaluation is important. |
| Adults/Aging | Evaluate for onset of Alzheimer’s disease and appropriate interventions and family support systems.15 Mobility systems should be assessed. |
Coordination of care
Multidisciplinary care with various specialists, including cardiologist, neurologist/neurosurgeon, orthopedist, pulmonologist, hematologist, physiatrist and developmental pediatrician, has the advantage of addressing all aspects of care. In the event that multidisciplinary clinics are unavailable, either the physiatrist or pediatrician would take the lead in coordinating care.
Patient & family education
Diagnosis of DS needs a referral to genetics to follow through with family counselling. A carrier of Robertsonian translocation will also need education about having a child with DS. The risk of recurrence is 10–15% if the mother is the translocation carrier and about 2.5% if the father is the carrier. If a parent carries the rare 21:21 translocation, all the offspring will have DS.11 Possibility of maltreatment, including physical and sexual abuse, should be addressed with individuals with disabilities and their families. Families need to be informed of educational options, including mainstream schooling and IEPs. Families also need to be educated regarding guardianship, financial planning, behavioral problems, school placement, vocational training, ADLs and residential facilities as children with DS age.
Emerging/unique interventions
Virtual reality training, either alone or in combination with motor training, may lead to improvements in sensory-motor functions.16
A study examining a 12-week group exercise intervention demonstrated a positive effect on improved memory performance in individuals with DS.17 A separate study looked at adding Pilates to PT to aid in balance and gross motor in DS patients and showed promise.18
A pilot study exploring the benefit of participation in social skills therapy (SST) and memory in children with Down syndrome had positive results.19
Translation into practice: Practice “pearls”/performance improvement in practice (PIPs)/changes in clinical practice behaviors and skills
Change in hypotonia to normal tone or hypertonia could be a subtle sign of cervical myelopathy as a result of atlantoaxial instability and should be closely monitored.
Developmental delay may be worsened by hypothyroidism.
Sleep apnea affects behavior and development.
It is important to remember that early poor and slow growth during infancy gives way to obesity approaching adolescence.
Predilection to DVT and development of hematological malignancies should be monitored closely. Deficiency of language production relative to other areas of development often causes substantial impairment.
Cutting Edge/Emerging and Unique Concepts and Practice
Research is ongoing to find out whether there are relationships between specific genetic changes and DS phenotypes.20
Genetic modification and nanotechnology are being explored to treat trisomy 21.21
Studies in mouse models of DS carried out over the past 20 years provide proof of principle evidence that neurogenesis can be pharmacologically ameliorated in DS, offering hope for fetal therapy to improve cognitive development.22
Early mobilization and early physical and occupational therapy are being explored to minimize motor delay in children with Down syndrome.23 Also optimal rehabilitation pathway to recommend home therapy, school-based therapy and other means of therapy are being tested.24,25
Gaps in the Evidence-Based Knowledge
Despite the screening/testing and management of associated conditions, no definite curative treatment is currently available for DS. Research is ongoing to focus on finding better function and quality of life. A lot of research is being done in rehabilitation therapies to improve speech, motor function, and cognitive function but currently lack randomized, well powered studies. Treatment strategies to decrease complications such as Alzheimer’s disease in individuals with DS have been investigated but there are no guidelines to prevent such complications.26
References
- Antonarakis SE, Skotko BG, Rafii MS, Strydom A, Pape SE, Bianchi DW, Sherman SL, Reeves RH. Down syndrome. Nature Reviews Disease Primers. 2020;6(9). doi: 10.1038/s41572-019-0143-7.
- Centers for Disease Control and Prevention. Data and statistics on down syndrome. https://www.cdc.gov/ncbddd/birthdefects/downsyndrome/data.html. Updated 2022. Accessed Mar 13, 2023.
- Mai CT, Isenburg JL, Canfield MA, Meyer RE, Correa A, Alverson CJ, Lupo PJ, Riehle-Colarusso T, Cho SJ, Aggarwal D, Kirby RS. National population-based estimates for major birth defects, 2010-2014. Birth Defects Research. 2019; 111(18):1420-1435. doi: 10.1002/bdr2.1589.
- Lagan N, Huggard D, Mc Grane F, et al. Multiorgan involvement and management in children with down syndrome. Acta paediatrica (Oslo, Norway: 1992). 2020. https://www.ncbi.nlm.nih.gov/pubmed/31899550. doi: 10.1111/apa.15153.
- Rondón-Avalo S, Rodríguez-Medina C, Botero JE. Association of Down syndrome with periodontal diseases: Systematic review and meta-analysis. Spec Care Dentist. 2024;44(2):360-368. doi:10.1111/scd.12892
- Koehler R, Pathy R, Gregory D, Mooney JF 3rd, Gannotti ME. Hip Dysplasia and Dislocation in Down Syndrome: Is There Evidence to Support Consideration of Routine Hip Surveillance?. J Pediatr Soc North Am. 2024;8:100074. Published 2024 Jun 26. doi:10.1016/j.jposna.2024.100074
- Rink BD, Dugoff L, Kuller JA. Society for Maternal-Fetal Medicine consult series #74: cell-free DNA screening for aneuploidies: updated guidance. Pregnancy 2025;1:e70139. doi: 10.1002/pmf2.70139
- Bani Bandana Ganguly (Ed.). (2022). Genetics and Neurobiology of Down Syndrome(pp. 135-180). London, UK: Associated Press.
- Sun E, Kraus CL. The Ophthalmic Manifestations of Down Syndrome. Children (Basel). 2023;10(2):341. Published 2023 Feb 9. doi:10.3390/children10020341
- Moriyama CH, Massetti T, Crocetta TB, et al. Systematic review of the main motor scales for clinical assessment of individuals with down syndrome. Developmental Neurorehabilitation. 2020;23(1):39-49. http://www.tandfonline.com/doi/abs/10.1080/17518423.2019.1687598. doi: 10.1080/17518423.2019.1687598.
- Bull MJ, The Council on Genetics. Health supervision for children and adolescents with down syndrome. Pediatrics. 2022;149(5):e2022057010. doi: 10.1542/peds.2022-057010.
- Ting CH, Rahman MM, Chen YY, et al. Employment of people with Down syndrome: A scoping review. Narra J. 2024;4(3):e1431. doi:10.52225/narra.v4i3.1431
- Jea A, Smith ER, Robertson R, Scott RM. Moyamoya syndrome associated with Down syndrome: outcome after surgical revascularization. Pediatrics. 2005;116(5):e694-e701. doi:10.1542/peds.2005-0568
- Puszczalowska-Lizis E, Nowak K, Omorczyk J, Ambrozy T, Bujas P, Nosiadek L. Foot structure in boys with Down Syndrome. Biomed Res Int. 2017;2017:7047468. doi: 10.1155/2017/7047468.
- Fortea J, Zaman SH, Hartley S, Rafii MS, Head E, Carmona-Iragui M. Alzheimer’s disease associated with Down syndrome: a genetic form of dementia. Lancet Neurol. 2021;20(11):930-942. doi:10.1016/S1474-4422(21)00245-3
- Lopes J, Duarte N, Lazzari R, Oliveira C. Virtual reality in the rehabilitation process for individuals with cerebral palsy and down syndrome: a systematic review. J Bodyw Mov Ther. 2020;24(4):479-83. doi: 10.1016/j.jbmt.2018.06.006.
- Ptomey L, Szabo A, Willis E, Gorczyca A, Greene J, Danon J, Donnelly J. Changes in cognitive function after a 12-week exercise intervention in adults with down syndrome. 2018;11(3):486-90. doi: 10.1016/j.dhjo.2018.02.003.
- Al-Nemr A, Reffat S. Effect of Pilates exercises on balance and gross motor coordination in children with Down syndrome. Acta Neurol Belg. 2024;124(5):1499-1505. doi:10.1007/s13760-024-02517-w
- Milojevich HM, Slonecker EM, Lukowski AF. Participation in social skills therapy is associated with enhanced recall memory by children with down syndrome: An exploratory study. Behav Modif. 2019:145445519841051. doi: 10.1177/0145445519841051.
- Yu YE, Xing Z, Do C, et al. Genetic and epigenetic pathways in down syndrome: Insights to the brain and immune system from humans and mouse models. Prog Brain Res. 2020;251:1-28. doi: S0079-6123(19)30197-9.
- Tafazoli A, Behjati F, Farhud DD, Abbaszadegan MR. Combination of genetics and nanotechnology for down syndrome modification: A potential hypothesis and review of the literature. Iran J Public Health. 2019;48(3):371-378.
- Stagni F, Bartesaghi R. The challenging pathway of treatment for neurogenesis impairment in down syndrome: achievements and perspectives. Front Cell Neurosci. 2022;16:903729. doi: 10.3389/fncel.2022.903729.
- Okada S, Uejo T, Hirano R, et al. Assessing the efficacy of very early motor rehabilitation in children with down syndrome. J Pediatr. 2019;213:227-231.e1. doi: S0022-3476(19)30655-9.
- Neal GE, Effgen SK, Arnold S, Baldwin J, Jeffries LM. Description of school-based physical therapy services and outcomes for students with down syndrome. J Autism Dev Disord. 2019;49(10):4019-4029. doi: 10.1007/s10803-019-04109-7.
- Walker BJ, Washington L, Early D, Poskey GA. Parents’ experiences with implementing therapy home programs for children with down syndrome: A scoping review. Occup Ther Health Care. 2020;34(1):85-98. doi: 10.1080/07380577.2020.1723820.
- Priebe GA, Kanzawa MM. Reducing the progression of alzheimer’s disease in down syndrome patients with micro-dose lithium. Med Hypotheses. 2020;137:109573. doi: S0306-9877(19)31233-2.
Original Version of the Topic
Rajashree Srinivasan, MD. Down Syndrome. 08/07/2012
Previous Revision(s) of the Topic
Mi Ran Shin, MD, Melissa Trovato, MD. Down Syndrome. 8/25/2016
Mi Ran Shin, MD, Courtney Sagar, MD, Olga Morozova, MD. Down Syndrome. 5/4/2020
Kavita Nadendla, MD, Melissa K. Trovato, MD. Down Syndrome. 4/20/2023
Author Disclosure
Gabrielle AM Schneider, DO
Nothing to Disclose
Jessica De Curtis Fernandez, MD
Nothing to Disclose
Melissa K. Trovato, MD
Nothing to Disclose