Down Syndrome

Down syndrome is a set of cognitive and physical symptoms that result from having an extra chromosome 21 or an extra piece of that chromosome. It is the most common chromosomal cause of mild to moderate intellectual disabilities. People with Down syndrome also have some distinct physical features, such as a flat-looking face, and they are at risk for a number of other health conditions.

Understanding Down syndrome and other intellectual and developmental disabilities is part of the reason the NICHD was established. Today, the Institute continues to lead research on the causes, progression, treatment, and management of Down syndrome, as well as on conditions and diseases that are associated with the syndrome.

New NIH Initiative: NICHD is pleased to be part of INCLUDE (INvestigation of Co-occurring conditions across the Lifespan to Understand Down syndromE), an NIH-wide initiative that launched in June 2018 in support of a Congressional directive in the fiscal year 2018 Omnibus Appropriations. The project aims to understand critical health and quality-of-life needs for individuals with Down syndrome, with the aim of yielding scientific discoveries to improve the health, well-being, and neurodevelopment of individuals with Down syndrome, as well as their risk and resilience common diseases that they share with individuals who do not have Down syndrome. INCLUDE will investigate conditions that affect individuals with Down syndrome and the general population, such as Alzheimer’s disease/dementia, autism, cataracts, celiac disease, congenital heart disease, and diabetes.

Common Name

  • Down syndrome

Medical or Scientific Names

  • Down syndrome
  • Trisomy 21
  • 47,XX,+21
  • 47,XY,+21