198-LB: A Novel Heterozygous Mutation in Peroxisome Proliferator-Activated Receptor Gamma (PPAR-γ) Gene in a Woman with Familial Partial Lipodystrophy

Background: The nuclear peroxisome proliferator-activated receptor gamma (PPAR-γ) plays a role in the regulation of glucose and lipid metabolism in adipocytes by regulating their differentiation, distribution and function. Heterogeneous mutations of PPAR-γ can cause loss of gene function or reduce its expression leading to a clinical variety of phenotypes that characterize type 3 familial partial lipodystrophy syndrome. The most common features of this syndrome are abnormal body fat accumulation, muscle hypertrophy, insulin resistance, hypertriglyceridemia, polycystic ovary syndrome and hepatic steatosis. Case report: A 32-year-old-woman was referred to the Endocrinology Division of PUC-SP for treatment of a severe hypertriglyceridemia diagnosed 4 years ago with recurrent episodes of acute pancreatitis and eruptive xanthomas since then. Also, diabetes mellitus (DM) was diagnosed 1 year ago with poor glycemic control. Her sister also had severe hypertriglyceridemia, recurrent episodes of acute pancreatitis and died in 2016. No DM was reported in her family. On physical examination, we found the presence of lipodystrophy, acanthosis nigricans on the neck and eruptive xanthomas on trunk, upper limbs, and thighs. BMI=24.9kg/m2; waist circumference=96cm. Abdominal CT scan revealed splenomegaly and fatty liver disease. Genetic sequencing showed a heterozygous (autosomal dominant inheritance) in the PPAR-γ of a Chr3 variant: 12.416.957 T> C (or alternatively c.1073T> C - ENST000002287820), promoting the substitution of leucine in codon 358 by proline (p.Leu358Pro). Conclusion: The substitution of the amino acid leucine in codon 358 for proline is highly conserved in several species, and computer programs for predicting in silico of pathogenicity, suggesting that this new heterozygous mutation in the PPAR-γ gene is probably related to the type 3 familial partial lipodystrophy syndrome.