Down syndrome, also called Trisomy 21, is a genetic
condition in which an individual has 47 chromosomes instead of 46. In most cases, an extra copy of
chromosome 21 is the cause of Down syndrome. This extra copy of the chromosome affects typical mental and
Severity of Down syndrome varies from person to person, but
common characteristics include:
- Decreased muscle tone at birth
- Small ears and mouth
- Upward slanting eyes
- Small stature
- Small hands and feet
Down syndrome is the most commonly occurring chromosomal
condition, and according to the CDC, one in 691 babies in the United States are
born with Down syndrome.
Children with Down syndrome might have delayed language
development and slow motor development.
Other health conditions that commonly occur with Down syndrome include
congenital heart disease, hearing problems, intestinal problems (blocked small
bowel or celiac disease), problems with memory or concentration, eye problems
(such as cataracts), or skeletal problems.
Most individuals with Down syndrome have an intellectual
disability, and they often have IQs within the mild to moderate range. Speech delays, as well as both fine and
gross motor delays are common, which can also interfere with cognitive
Children with Down syndrome can benefit from a variety of
therapies, including speech, occupational, and physical therapy. They might require special education,
while many others can be integrated in a typical classroom. There is no “cure” for Down syndrome,
but these therapies can help provide a person with skills for independent
According to the National Down Syndrome Society, life
expectancy for individuals with Down syndrome has increased from age 25 in 1983
to age 60 today. Many people with
Down syndrome attend school, work, live independently, maintain marriages and
relationships, and contribute to society in many other ways. To read more about self-advocacy, visit
the National Down Syndrome Congress.