OverviewA simian crease is a single palmar crease as compared to two creases in a normal palm. Simian crease occurs in about 1 out of 30 normal people, but is also frequently associated with other conditions such as Down syndrome, Aarskog syndrome or fetal alcohol syndrome.
Update Date 8/30/2014
Updated by: Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.