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.

The symptoms of Down syndrome vary from person to person, and people with Down syndrome may have different problems at different times of their lives.

Down syndrome is caused by a random error in cell division that results in the presence of an extra copy of chromosome 21.

Researchers know some, but not all, of the risk factors for Down syndrome.

Health care providers can check for Down syndrome during pregnancy or after a child is born. There are two types of tests for Down syndrome during pregnancy.

There is no single, standard treatment for Down syndrome. Treatments are based on each individual’s physical and intellectual needs, as well as their personal strengths and limitations.

In addition to intellectual and developmental disabilities, children with Down syndrome are at an increased risk for certain health problems.

NICHD has a long-standing history of supporting and conducting diverse research on Down syndrome.

NICHD conducts and supports a variety of research projects related to Down syndrome.

Find answers to other common questions about Down syndrome, such as how to prepare teens with Down syndrome for adulthood and what health issues might affect adults with Down syndrome.

Links to websites of groups that study or provide information about Down syndrome.