Early Intervention

Down syndrome is the most frequent genetic cause of intellectual disability and associated medical problems and occurs in one out of 691 live births, in all races and economic groups. Named after John Langdon Down, the first physician to identify the cell abnormality, Down syndrome is a chromosomal disorder caused by an error in cell division that results in the presence of a third chromosome 21 or “Trisomy 21.”

Down syndrome occurs when an individual has a full or partial extra copy of chromosome 21. This additional genetic material alters the course of development and causes the characteristics associated with Down syndrome.

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.

Life expectancy for people with Down syndrome has increased dramatically in recent decades – from 25 in 1983 to 60 today.

People with Down syndrome attend school, work, participate in decisions that affect them, have meaningful relationships, vote and contribute to society in many wonderful ways.

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 lead fulfilling and productive lives.

To learn more about the chromosomal causes of Down syndrome, the three types of Ds, and the history of its discovery, visit the National Down Syndrome Society’s website.