Congenital generalized lipodystrophy, also known as Berardinelli-Seip syndrome, is a rare genetic disease characterized by a near absence of adipose tissue from birth or early infancy, severe insulin resistance, and metabolic abnormalities. Symptoms include acanthosis nigricans, muscular hypertrophy, hepatomegaly, altered glucose tolerance, and hypertriglyceridemia. The disease is caused by mutations in the AGPAT2 gene on chromosome 9q34.3 and follows an autosomal recessive pattern of inheritance.