What is simian crease?

Palm lines. Most folks have two lines across the palm joining the side below the little finger with the space between the thumb and index finger. If only one is present, as in some monkeys ("simians") & in 1% of normal folks, it's a tip-off that the person may have another birth defect, especially trisomy 21, but ultimately it's of no use as the other defects will be obvious.

Related Questions

What is a simian crease/line?

Single palmar crease. Simian crease is a single line that goes across one's palm without a break in the crease or line. In some people this finding can be associated with down syndrome. Read more...
Single palmer crease. Most people have a split palm fold/crease that begins at the lateral palm border & turns up between the index & second finger.A second crease starts above the thumb & breaks up before reaching the lateral palm border.The simian (apelike) crease joins the two as one.It is thought to represent less muscle tone during fetal development.It occurs in both nl people & a higher # with Down syndrome. Read more...