Single- and multilocus allelic variants within the GABA(B) receptor subunit 2 (GABAB2) gene are significantly associated with nicotine dependence

Am J Hum Genet. 2005 May;76(5):859-64. doi: 10.1086/429839. Epub 2005 Mar 9.

Abstract

Twelve single-nucleotide polymorphisms (SNPs) in the human gamma-aminobutyric acid type B (GABA(B)) receptor subunit 2 gene (GABAB2) were tested for association with nicotine dependence (ND) in an extensively phenotyped cohort of 1,276 smokers and nonsmokers, representing approximately 404 nuclear families of African American (AA) or European American (EA) origin. The GABAB2 gene encodes a subunit of the GABA(B) receptor for GABA, an inhibitory neurotransmitter involved in the regulation of many physiological and psychological processes in the brain. The gene is located within a region of chromosome 9q22 that showed a "suggestive" linkage to ND. Individual SNP analysis performed using the PBAT-GEE program indicated that two SNPs in the AAs and four SNPs in the EAs were significantly associated with ND. Haplotype analysis using the Family-Based Association Test revealed that, even after Bonferroni correction, the haplotype C-C-G of rs2491397-rs2184026-rs3750344 had a significant positive association with ND in both the pooled and the AA samples. In the EAs, we identified two haplotypes, C-A-C-A and T-A-T-A, formed by SNPs rs1435252-rs378042-rs2779562-rs3750344, that showed a highly significant negative and positive association with ND, respectively. In summary, our findings provide evidence of a significant association of GABAB2 variants with ND, implying that this gene plays an important role in the etiology of this drug addiction.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Alleles
  • Black or African American / genetics
  • Cohort Studies
  • Female
  • Genetic Predisposition to Disease*
  • Genetic Variation*
  • Haplotypes
  • Humans
  • Male
  • Middle Aged
  • Polymorphism, Single Nucleotide
  • Receptors, GABA-B / genetics*
  • Tobacco Use Disorder / genetics*
  • White People / genetics

Substances

  • Receptors, GABA-B