A polymorphism of the interferon-gamma-inducible protein 30 gene is associated with hyperglycemia in severely obese individuals

Hum Genet. 2012 Jan;131(1):57-66. doi: 10.1007/s00439-011-1043-4. Epub 2011 Jun 24.

Abstract

A previous expression profiling of visceral adipose tissue (VAT) revealed that the immune response gene interferon-gamma-inducible protein 30 (IFI30) gene was 1.72-fold more highly expressed in non-diabetic severely obese men with the metabolic syndrome as compared to those without. Given the importance of low-grade inflammation in obesity-related metabolic complications, we hypothesized that variants in the IFI30 gene are associated with cardiovascular disease (CVD) risk factors. A detailed genetic investigation was performed at the IFI30 locus by sequencing its promoter, exons and intron-exon junction boundaries using DNA of 25 severely obese men. Among the 21 sequence-derived single-nucleotide polymorphisms (SNPs), 5 tagged SNPs (covering 100% of the common SNPs identified) were genotyped in two independent samples of severely obese patients (total n = 1,283). Using a multistage experimental design, chi-square analyses and logistic regressions were performed to compare genotype frequencies and compute odds-ratios (OR) for low and high CVD risk groups (dyslipidemia, hyperglycemia/diabetes and hypertension). A significant association was observed with the non-synonymous SNP rs11554159 (p.R76Q), where GA individuals showed lower risk (OR = 0.67; P = 0.0009) for hyperglycemia/diabetes as compared to homozygotes for the major allele (GG). No association was observed between rs11554159 and VAT IFI30 mRNA levels (P = 0.81), and the expression levels were not correlated with fasting plasma glucose levels (P = 0.31) in 112 non-diabetic severely obese women. The localization of rs11554159 near the active site of IFI30 suggests a functional effect of this SNP. This study showed a novel association between rs11554159 (p.R76Q) polymorphism at the IFI30 locus and the risk of hyperglycemia/diabetes in severely obese individuals.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Cardiovascular Diseases / etiology
  • Cardiovascular Diseases / pathology
  • Case-Control Studies
  • Diabetes Mellitus / etiology
  • Diabetes Mellitus / pathology
  • Female
  • Genetic Predisposition to Disease
  • Genotype
  • Humans
  • Hyperglycemia / etiology*
  • Hyperglycemia / pathology
  • Linkage Disequilibrium
  • Male
  • Obesity / complications*
  • Obesity / genetics*
  • Oxidoreductases Acting on Sulfur Group Donors / genetics*
  • Polymorphism, Single Nucleotide / genetics*
  • RNA, Messenger / genetics
  • Real-Time Polymerase Chain Reaction
  • Risk Factors

Substances

  • RNA, Messenger
  • IFI30 protein, human
  • Oxidoreductases Acting on Sulfur Group Donors