Simpson-Golabi-Behmel syndrome (SGBS, also referred to as SGBS type 1) is a rare X-linked multiple congenital anomalies syndrome, characterized by pre- and postnatal overgrowth, distinctive craniofacial features, variable congenital malformations, organomegaly and an increased tumor risk.

A gap in the upper lip. This is a congenital defect resulting from nonfusion of tissues of the lip during embryonal development.