- Down syndrome is a set of cognitive and physical characteristics that result from having three (rather than two) copies of the 21st chromosome, or an extra piece of that chromosome. This condition is called trisomy 21.
- Scientists worldwide are still working to understand how the extra chromosome 21 genes cause an individual to have Down syndrome.
- Down syndrome is the most commonly occurring chromosomal condition. Each year, about 5,700 babies born in the United States have down syndrome, meaning that Down syndrome occurs in about 1 in every 640 babies in the U.S.
- Down syndrome affects people of all ages, races, and economic levels.
- We do not know for sure why Down syndrome occurs or how many different factors play a role. We do know that the chance of having a baby with Down syndrome increases with the mother's age. But due to higher fertility rates in younger women, most babies with Down syndrome are born to women under 35 years of age.
- People with Down syndrome have an increased risk for certain medical conditions such as congenital heart defects, respiratory concerns, hearing problems, Alzheimer's disease, childhood leukemia, and thyroid conditions. Many of these conditions are now treatable, so most people with Down syndrome lead healthy lives.
- A few of the common physical traits of Down syndrome are low muscle tone, small stature, an upward slant to the eyes, and a single deep crease across the center of the palm. Every person with Down syndrome is a unique individual and may possess these characteristics to different degrees or not at all.
- The average life expectancy for people with Down syndrome has increased dramatically in recent decades - from 25 years in 1983 to 60 years today.
- All people with Down syndrome have learning delays that are usually mild to moderate, but they also have many strengths and abilities.
- Quality educational programs, a stimulating home environment, good health care, and positive support from family, friends, and the community enable people with Down syndrome to develop their full potential and lead fulfilling lives.
- People with Down syndrome attend school, find work, participate in decisions that affect them, and contribute to society.
For more facts and information about Down syndrome, please visit the following sites:
Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)