What is Down syndrome?

There is a nucleus in every cell in the human body where genetic material is stored in genes. Genes carry the codes responsible for all of our inherited traits and are grouped along with rod-like structures called chromosomes. Typically, the nucleus of each cell contains 23 pairs of chromosomes, half of which are inherited from each parent. 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 – although each person with Down syndrome is a unique individual and may possess these characteristics to different degrees, or not at all.

There are three types of Down syndrome Trisomy 21 (nondisjunction) accounts for 95% of cases, Translocation accounts for about 4%, and Mosaicism accounts for about 1%.

The cause of the extra full or partial chromosome is still unknown. Maternal age is the only factor that has been linked to an increased chance of having a baby with Down syndrome resulting from nondisjunction or mosaicism. There is no definitive scientific research that indicates that Down syndrome is caused by environmental factors or the parents’ activities before or during pregnancy. The additional partial or full copy of the 21st chromosome causes Down syndrome to originate from either the father or the mother. Approximately 5% of the cases have been traced to the father

Facts About Down Syndrome!

Down syndrome occurs in 1 out of 691 live births.
Down syndrome occurs in individuals of all races and economic levels.
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.
More than 400,000 people living in the United States have Down syndrome.
The incidence of births of children with Down syndrome increases with the age of the mother. But due to higher fertility rates in younger women, 80% of children with Down syndrome are born to women under 35 years of age.
Life expectancy for people with Down syndrome has increased dramatically in recent decades – from 25 in 1983 to 60 today.
Many people with Down syndrome hold jobs in adulthood, live independently, have meaningful relationships, vote, and contribute to society.
There are three types of Down syndrome: trisomy 21 (nondisjunction) accounts for 95% of cases, translocation accounts for about 4%, and mosaicism accounts for about 1%.
Individuals born with Down syndrome have an increased risk for certain medical conditions such as congenital heart defects, respiratory and hearing problems, Alzheimer’s disease, childhood leukemia, and thyroid conditions. Many of these conditions are now treatable, so most individuals with Down syndrome live 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.
All individuals born with Down syndrome experience cognitive delays, but the effect is usually mild to moderate and is not indicative of the many strengths and talents that each individual possesses.

What is Down syndrome?

NDSS - National Down Syndrome Society

Facts About Down Syndrome!

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