title: Increased frequency of the G972R variant of the insulin receptor substrate-1 (irs-1) gene among girls with a history of precocious pubarche.
abstract: To test the hypothesis that lower sex hormone-binding globulin (SHBG) concentrations are associated with heterozygosity for the G972R variant of the IRS-1 gene among adolescent girls with a history of precocious pubarche (PP) and hyperinsulinemic ovarian hyperandrogenism.Association study. Academic research environment. Adolescent girls with a history of PP and healthy adolescent female control subjects. Determine body mass index; measure serum androgen, insulin-like growth factor (IGF)-binding protein 1, lipids, IGF-1, and SHBG concentrations; perform glucose tolerance tests; and assay for G972R variant of the IRS-1 gene. Serum androgen, IGFBP-1, and SHBG concentrations; IRS-1 genotypes.Twenty-five of 54 (45%) girls with a history of PP developed hyperinsulinemic ovarian hyperandrogenism at adolescence. Frequency of heterozygosity for G972 was 31% among girls with a history of PP, 40% among girls with hyperinsulinemic ovarian hyperandrogenism, and 19% among healthy control subjects. Sex hormone-binding globulin concentrations were lower among girls heterozygous for G972R variant. Predictors of progression from PP to hyperinsulinemic ovarian hyperandrogenism included chronological age, insulin, low-density lipoprotein cholesterol, and IGFBP-1 concentrations. The low mean SHBG concentration found among G972R carriers suggests that this variant may be a minor locus associated with development of hyperinsulinemic insulin resistance and ovarian androgen excess in girls with a history of PP.
authors.affiliation: Endocrinology Unit, Hospital Sant Joan de Deu, University of Barcelona, Barcelona, Spain.
authors.forename: Lourdes
authors.initials: L
authors.lastname: Ibáñez
authors.forename: Maria Victoria
authors.initials: MV
authors.lastname: Marcos
authors.forename: Neus
authors.initials: N
authors.lastname: Potau
authors.forename: Carlie
authors.initials: C
authors.lastname: White
authors.forename: Christopher E
authors.initials: CE
authors.lastname: Aston
authors.forename: Selma Feldman
authors.initials: SF
authors.lastname: Witchel
mesh_terms: D000293:Adolescent; D000728:Androgens / Q000097:blood; D005260:Female; D005787:Gene Frequency; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D017588:Hyperandrogenism / Q000150:complications; D006946:Hyperinsulinism / Q000150:complications; D055504:Insulin Receptor Substrate Proteins; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000097:blood; D008499:Medical Records; D009994:Osmolar Concentration; D010049:Ovarian Diseases / Q000150:complications; D010750:Phosphoproteins / Q000235:genetics*; D011629:Puberty, Precocious / Q000097:blood / Q000150:complications / Q000235:genetics*; D012738:Sex Hormone-Binding Globulin / Q000032:analysis
chemical_list: D000728:Androgens; C526292:IRS1 protein, human; D055504:Insulin Receptor Substrate Proteins; D018970:Insulin-Like Growth Factor Binding Protein 1; D010750:Phosphoproteins; D012738:Sex Hormone-Binding Globulin