BSCL2 and congenital generalized lipodystrophy type 2: Seipin/BSCL2 has been identified as the pathogenic gene for Berardinelli-Seip congenital lipodystrophy type 2 (BSCL2) and induces the most severe form of lipodystrophy, characterized by an almost complete absence of adipose tissue and associated metabolic disorders.