Congenital generalized Lipodystrophy (BSCL) or Berardinelli-Seip syndrome (Mendelian inheritance in man, catalog no. 269700) is a rare autosomal recessive syndrome characterized by paucity of body fat since birth and insulin resistance. The pathophysiology of this condition is unclear, but defects in insulin function and impaired adipogenesis have been described as important factors in the etiology of the disease. Recently, two gene loci have been identified to harbor the mutations causing this disorder: BSCL1 mapped to human chromosome 9q34 (1, 2) and BSCL2 mapped to human chromosome 11q13 (1, 3). This report describes the natural history of the disease in two siblings (female and male) of Lebanese origin who have mutations in the BSCL2 locus (669delGTATC).