Novel nonsense mutation in UNC80 in a Turkish patient further validates the sociable skill and severe gastrointestinal problems as part of disease spectrum.

NALCN channelosome complex contributes to maintaining resting membrane potential. The complex has four domains including two intracellular domains (UNC79 and UNC80), one transmembrane domain (NALCN) and one extracellular domain (FAM155A). Mutations in UNC80 were previously linked to infantile hypotonia with psychomotor retardation and characteristics facies 2.