What is simean crease?

The simian crease, also known as a single transverse palmar crease, is a single line that runs across the palm of the hand, instead of the typical two creases. It is a genetic variation that occurs in some individuals and can be associated with certain genetic conditions, such as Down syndrome. The presence of a simian crease is not necessarily indicative of any medical issues, as it can also occur in individuals without any health concerns.