what is simeon's crease?

Question

I've been told that it's a certain crease found on the hand of some infants at birth, but no one seems to know what it is, or what it means and who simeon is.

Answer 1

It's "simian crease," as in monkey.

It may be a sign of genetic abnormalities, such as Down's syndrome, but it's often just a physical oddity.

Answer 2

It is a sign of downs syndrome