Down Syndrome Fast Facts

(CNN)Here's a look at Down syndrome.

Down syndrome is a genetic condition that affects cognitive ability, causing mild to severe learning disabilities and distinctive facial characteristics. There are three types of Down syndrome: translocation, mosaicism and trisomy 21. Trisomy 21 is the most common and contributes to 95% of cases.
Characteristics:
English physician John Langdon Down first characterized it in 1866.
    It is a condition or syndrome, not a disease.
    It is due to extra material in chromosome 21. In those with trisomy 21, the individual possesses a full extra copy of the chromosome.
    Risk factors that might lead to the conception of a child with Down syndrome include advanced maternal age or a parent with Down syndrome. A couple that already have a child with Down syndrome has a one percent chance of conceiving another.
    The condition can be diagnosed through various prenatal screening tests.
    Physical characteristics - small stature, decreased muscle tone, irregular shaped ears, a flat face, eyes that slant upward, a deep crease across the palm of the hands, the ability to extend joints beyond the usual range, a large space between the big toe and the next toe, and a large tongue relative to the mouth size.
    Health - Those with the condition may also have, or are at risk for, heart defects, vision and/or hearing impairment, thyroid conditions, obesity, gastrointestinal conditions, memory loss, seizures and some cancers.
    Statistics:
    In the United States, about 6,000 children are born with Down Syndrome annually.
    In 2008, More than 250,000 people in the United States had Down syndrome.
    Life expectancy is currently 50-60 years.
    Language Tips from the National Down Syndrome Society:
    Down syndrome, without an 's, is the preferred spelling.
    "A child/adult with Down syndrome" is the preferred reference, as opposed to "he/she has Down's," or is "afflicted" or "suffers."
    The emphasis should be that he/she is a child/adult first, and as a secondary consideration it could be said that the individual has Down syndrome.