In the differential diagnosis of LFS, another disorder that exhibits some features and symptoms of LFS and is also associated with a missense mutation of MED12 is Opitz-Kaveggia syndrome (FGS). Common features shared by both LFS and FGS include X-linked intellectual disability, hyperactivity, macrocephaly, corpus callosum agenesis and hypotonia. Notable features of FGS that have not been reported with LFS include excessive talkativeness, consistent strength in socialization skills, imperforate anus (occlusion of the anus) and ocular hypertelorism (extremely wide-set eyes).
