My friend has a baby who was just born. they are worried that he doesn't have enough chromosomes, and his hand only has 1 line on it. what could it b?

See a Doctor: Your friend should have their child evaluated by a physician if they are concerned. The "one line" on the hand you speak of may be a simian crease which is actually associated with too many chromosomes; trisomy 21 or commonly known as down syndrome. There is really not enough information to make a determination, but genetic testing and other symptoms may shed some light on their concern.

Geneticist can help: Parents in consultation with the OB and peds doctors may choose to keep private what they discuss and learn. In general, if a newborn has appearance that is unusual, a test or tests will be done for chromosomes and genetic information, and, if available, a pediatric geneticist will be called. Even if the baby is given a tentative diagnosis, family and friends should wait for final test results.