A description of trisomy 18

Trisomy 18 is a chromosomal condition associated with abnormalities in many parts of the body. People with trisomy 18 have slow growth before birth and a low birth weight. Features of trisomy 18 include a small, abnormally shaped head,a small jaw and mouth,and clenched fists with overlapping fingers. Due to the presence of several life-threatening medical problems, many individuals with trisomy 18 die before birth or within their first month. Five to 10 percent of children with this condition live past their first year, but usually do not live past the age of 3.