Open AccessDivergent Metabolic Phenotype between Two Sisters with Congenital Generalized Lipodystrophy Due to Double AGPAT2 Homozygous Mutations. A Clinical, Genetic and In Silico Study
Author(s) -
Víctor Cortés,
Susan V. Smalley,
Denisse Goldenberg,
Carlos F. Lagos,
María Isabel Hodgson,
José Luis Santos
Publication year - 2014
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0087173
Subject(s) - missense mutation , exon , genetics , biology , lipodystrophy , in silico , mutation , rna splicing , intron , phenotype , gene , rna , virus , antiretroviral therapy , viral load
Congenital generalized lipodystrophy (CGL) is a rare autosomal recessive disorder characterized by extreme reduction of white adipose tissue (WAT) mass. CGL type 1 is the most frequent form and is caused by mutations in AGPAT2 . Genetic and clinical studies were performed in two affected sisters of a Chilean family. These patients have notoriously dissimilar metabolic abnormalities that correlate with differential levels of circulating leptin and soluble leptin receptor fraction. Sequencing of AGPAT2 exons and exon-intron boundaries revealed two homozygous mutations in both sisters. Missense mutation c.299G>A changes a conserved serine in the acyltransferase NHX4D motif of AGPAT2 (p.Ser100Asn). Intronic c.493-1G>C mutation destroy a conserved splicing site that likely leads to exon 4 skipping and deletion of whole AGPAT2 substrate binding domain. In silico protein modeling provided insights of the mechanisms of lack of catalytic activity owing to both mutations.