Tags: Disease.
FG syndrome (FGS; also known as Opitz–Kaveggia syndrome) is a rare genetic syndrome linked to the X chromosome and causing physical anomalies and developmental delays. First reported by Opitz and Kaveggia in 1974 its major clinical features include retardation hyperactivity hypotonia (low muscle tone) and a characteristic facial appearance including macrocephaly (an abnormally large head).