BSCL2 and Berardinelli-Seip congenital lipodystrophy: Dysfunctional seipin, resulting from mutations in the BSCL2 gene, causes congenital generalized lipodystrophy type 2, a severe inherited disorder characterized by near-complete loss of adipose tissue, likely due to impaired mesenchymal stem cell differentiation into preadipocytes [41].