Genetic variants of FOXA2: risk of type 2 diabetes and effect on metabolic traits in North Indians

J Hum Genet. 2008;53(11-12):957-965. doi: 10.1007/s10038-008-0335-6. Epub 2008 Sep 17.

Abstract

Here, we examined the association of genetic variants of FOXA2, an upstream activator of the beta-cell transcription factor network, with type 2 diabetes and related phenotypes in North India. We genotyped three SNPs (rs1212275, rs1055080, rs6048205) and the (TCC)( n ) repeat polymorphism in 1,656 participants comprising 1,031 patients with type 2 diabetes and 625 controls. SNPs rs1212275 and rs6048205 were uncommon (MAF < 5%) with similar distribution among patients and controls. We found a strong association of (TCC)( n ) common allele A5 with type 2 diabetes [OR = 1.66 (95% CI 1.36-2.04, p = 5.9 x 10(-7)) for A5 homozygotes]. Obese individuals with A5A5 genotype had enhanced risk when segregated from normal-weight subjects [OR = 1.92 (95% CI 1.47-2.51), p = 1.6 x 10(-6)]. A5 was also nominally associated with higher fasting glucose (p = 0.02) and lower fasting insulin (p = 0.0028) and C-peptide (p = 0.036) levels among controls. At the rs1055080 locus, GG was found to provide reduced risk among normal-weight subjects [OR = 0.59 (95% CI 0.40-0.88), p = 0.011]. Combination of protective GG and non-risk genotypes of (TCC)( n ) showed reduced risk of type 2 diabetes both among normal-weight [OR = 0.43 (95% CI 0.29-0.65), p = 1.2 x 10(-6)] and obese individuals [0.47 (95% CI 0.34-0.64), p = 4.3 x 10(-5)]. For the first time we demonstrated that FOXA2 variants may affect risk of type 2 diabetes and metabolic traits in North India, however replication analyses in other cohorts are required to confirm the findings.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Blood Glucose / metabolism*
  • C-Peptide / blood*
  • Case-Control Studies
  • Diabetes Mellitus, Type 2 / blood
  • Diabetes Mellitus, Type 2 / epidemiology
  • Diabetes Mellitus, Type 2 / genetics*
  • Female
  • Genetic Predisposition to Disease*
  • Genotype
  • Hepatocyte Nuclear Factor 3-beta / genetics*
  • Humans
  • India / epidemiology
  • Insulin / blood*
  • Male
  • Middle Aged
  • Obesity / genetics
  • Polymerase Chain Reaction
  • Polymorphism, Genetic / genetics*
  • Risk Factors

Substances

  • Blood Glucose
  • C-Peptide
  • FOXA2 protein, human
  • Insulin
  • Hepatocyte Nuclear Factor 3-beta