Alcohol use disorder and GABAB receptor gene polymorphisms in an Italian sample: haplotype frequencies, linkage disequilibrium and association studies

• Published in: Annals of Human Biology Vol. 44; no. 4; pp. 384 - 388
• Main Authors: Caputo, Fabio, Ciminelli, Bianca Maria, Jodice, Carla, Blasi, Paola, Vignoli, Teo, Cibin, Mauro, Zoli, Giorgio, Malaspina, Patrizia
• Format: Report
• Language: English
• Published: Taylor & Francis 19.05.2017
• Subjects: AUD; GABBR1; GABBR2; Single nucleotide polymorphism; SNP
• ISSN: 0301-4460; 1464-5033
• DOI: 10.1080/03014460.2017.1287307

Background: Alcohol use disorder (AUD) is a complex trait with genetic and environmental influences. Several gene variants have been associated with the risk for AUD, including genes encoding the sub-units of the γ-aminobutyric acid (GABA) receptors. Aim: This study evaluated whether specific single nucleotide polymorphisms (SNPs) in genes encoding GABA B receptor sub-units can be considered as candidates for the risk of AUD. Subjects and methods: Seventy-four AUD subjects and 128 Italian controls were genotyped for 10 SNPs in genes encoding GABA-B1 and GABA-B2 sub-units (GABBR1 and GABBR2). Allele, genotype, and haplotype frequencies were tested for the association with the AUD trait. Results: A significant difference between AUD individuals and controls was observed at genotype level for rs2900512 of GABBR2 gene. The homozygous T/T genotype was not found in the controls, whereas it was over-represented in the AUD individuals. Under the recessive model (T/T vs C/T + C/C) this result was statistically significant, as well as the Odds Ratio for the association with the AUD trait. Conclusions: The results provide preliminary data on the association between GABA B receptor gene variation and risk of AUD. To confirm this finding, studies with larger samples and additional characterisation of the phenotypic AUD trait are required.