Down syndrome occurs when an individual has a
full or partial extra copy of chromosome twenty one. One in every six hundred
and ninety one babies in America is born with Down syndrome, making Down
syndrome the most common genetic condition. Approximately four hundred thousand
Americans have Down syndrome. The cause of Down syndrome is currently unknown,
but research has shown that it increases in frequency as a women ages. There is
definitive scientific research that proves that Down syndrome is not caused by
environmental factors or parents’ activities before or during pregnancy. The
additional partial or full copy of the 21st chromosome which causes
Down syndrome can originate from either the father or the mother. Approximately
5% of cases have been traced back to the father. Down syndrome is usually identified at birth by
the presence of certain physical characteristics such as low muscle tone, a
single deep crease across the palm of the hand, a slightly flattened facial
profile and an upward slant to the eyes. Since many couples are postponing parenting until
later in life, the incidence of Down syndrome is expected to increase.