Heterogeneity for congenital generalized lipodystrophy in seventeen patients from Oman

Abstract

Seventeen children with congenital generalized lipodystrophy or Berardinelli-Seip Congenital Lipodystrophy (BSCL) from 12 consanguineous sibships were observed in Oman. All children had widespread absence of adipose tissue from infancy together with apparent muscle hypertrophy and hepatomegaly. They did not appear to represent a single homogenous entity, and it was possible to subclassify the cases into two distinct groups. In the first group of seven cases, the features were similar to other published cases with acanthosis nigricans, raised insulin levels, and insulin resistance. In this group, there was an association between the degree of acanthosis nigricans and the severity of the disorder. Molecular analysis of these cases showed homozygosity at the BSCL2 locus on chromosome 11q13 in four of the seven cases. In the second group of ten cases, there were striking abnormalities in both skeletal and nonskeletal muscle. Reduced exercise tolerance and percussion myoxedema were observed in skeletal muscle, while infantile hypertrophic pyloric stenosis, prominent veins (phlebomegaly), disturbance of cardiac rhythm, and cardiomyopathy were observed in nonskeletal muscle. There was evidence against homozygosity in some cases for the known loci for BSCL, and this group may represent a new clinical syndrome with lipodystrophy at a different genetic location.