About Us | Privacy | Site Map
February 8, 2012
Font Size
A
A
A

Down Syndrome (cont.)

Medical Author:
Medical Editor:

Down Syndrome Symptoms (the Effects of Trisomy 21)

It is now well known that the extra genes on the additional chromosome 21 are the cause of Down syndrome. Scientists are trying to determine which of the genes on chromosome 21 cause different characteristics of the disorder when present in three copies. Some genes may be more active and others less active due to the extra copy, and some of the genes may have a stronger influence on the characteristics of Down syndrome than others. Currently, about 400 genes on chromosome 21 have been identified, but the function of most remains unknown.

Until recently, scientists hypothesized that the most important genes involved in Down syndrome were located in an area on chromosome 21 called the Down syndrome critical region. However, scientists have found that genes outside this region are also important in Down syndrome.

Women's Health

Find out what women really need.




Read What Your Physician is Reading on Medscape

Down Syndrome »

In 1866, Down described clinical characteristics of the syndrome that now bears his name.

Read More on Medscape Reference »

Medical Dictionary


Use Pill Finder Find it Now

Pill Identifier on RxList

  • quick,
    easy,
    pill identification

Find a Local Pharmacy

  • including
    24 hour
    pharmacies