Summary
Berardinelli-Seip congenital lipodystrophy (BSCL) is characterized by the association of lipoatrophy, hypertriglyceridemia, hepatomegaly and acromegaloid features. BSCL belongs to the group of extreme insulin resistance syndromes, which also includes leprechaunism, Rabson-Mendenhall syndrome, acquired generalized lipodystrophy, and types A and B insulin resistance (see these terms). The prevalence of BSCL in the general population of Europe is estimated at 1/400,000. BSCL is associated with insulin resistance resulting in clinically overt diabetes mellitus with onset during the second decade. Complications include hypertrophic cardiomyopathy, a fatty liver with hepatic dysfunction, muscular hypertrophy, a number of endocrine disturbances (accelerated growth in infancy, precocious puberty etc.) and bone cysts with spontaneous fractures. Two causative genes have been identified: AGPAT2 (9q34), encoding a key enzyme in triglyceride biosynthesis (1-acyl-glycerol-3-phosphate-O-acyltransferase-2), and BSCL2 (11q13), encoding the seipin protein. Intellectual deficit is observed in the majority of patients carrying BSCL2 mutations. Transmission is autosomal recessive. Diagnosis is based on recognition of the clinical picture and associated biochemical disturbances, and may be confirmed by genetic testing. Differential diagnoses include laminopathies and Parry-Romberg syndrome (see these terms). Treatment consists of a low fat diet, and appropriate management of the insulin resistance and diabetes. Prognosis depends on the presence of associated complications.*Author: Pr L. Van Maldergem (January 2009)*.