Association between neurotensin receptor 1 gene polymorphisms and alcohol dependence in a male Han Chinese population

Neurotensin (NT) is a 13-amino acid multifunctional neuropeptide. Previous studies have demonstrated the roles of NT and its high-affinity receptor 1 (NTR1) in genetically mediated differential sensitivities to alcohol. However, no studies have investigated the association between NTR1 gene single-nucleotide polymorphisms (SNPs) and alcohol dependence (AD). We therefore examined this link. We genotyped three SNPs (rs6090453C/G, rs6011914C/G, and rs2427422A/G) of NTR1 gene in 127 AD patients and 131 healthy controls drawn from Han Chinese males. Allele and genotype frequencies were compared, and linkage disequilibrium and haplotype analysis were performed. For rs6011914C/G, the frequencies of GG genotypes in AD patients showed an increased trend compared with controls (p = 0.057), and the ratio of GG/(CG + CC) for dominant model in AD patients was significantly higher (p = 0.024). For rs2427422A/G, both the frequencies of G alleles and GG genotypes and the ratio of GG/(AG + AA) for dominant model in AD patients were significantly higher compared with controls (p = 0.003, 0.006, 0.002, respectively). There was no significant difference in the frequencies of alleles, genotypes, and dominant or recessive model for rs6090453C/G (all p > 0.05). There were three pairs of SNP linkage disequilibriums, and the haplotype frequencies differed significantly between patients and controls for the CCA (p = 0.005, less frequent in the patients) and CCG (p = 0.002, more frequent in the patients) haplotypes. The current study supported an association between NTR1 gene variants and AD in the Han Chinese population.