Gene Variation Linked with Alcoholic Drinking Intensity
Single nucleotide polymorphism in the SLC6A4 gene may have therapeutic implications
MONDAY, Nov. 24 (HealthDay News) -- An inherent genetic variation associated with serotonin may hold a clue to an individual's alcoholic drinking intensity, according to a report released online Nov. 20 in advance of publication in the January issue of Alcoholism: Clinical & Experimental Research.
Chamindi Seneviratne, Ph.D., of University of Virginia Department of Psychiatry and Neurobehavioral Sciences in Charlottesville, and colleagues investigated 275 treatment-seeking alcoholics (216 males, 59 females) of white and Hispanic origin for six genetic polymorphisms in the gene SLC6A4 coding for human serotonin (5-HTT) associated with drinking intensity. Using site-directed mutagenesis techniques, the researchers transfected cells with a plasmid carrying either T or G alleles of the gene, to measure the levels of serotonin transporter mRNA and protein expression.
The investigators found that rs1042173 in the 3' untranslated region of SLC6A4 gene showed a significant association with drinking intensity. Individuals who were homozygous for T allele of the SNP rs1042173 had more severe drinking intensity (associated with lower serotonin mRNA and protein levels) than G allele carriers, although both the allelic groups were heavy alcoholics (over or equal to five and four standard drinks/day for men and women, respectively).
"Further studies with a large sample size are needed to confirm our findings, and to determine whether alcohol-dependent individuals with these allelic differences at the 3' UTR SNP rs1042173 would vary in response to different types of specific serotonergic medication," the authors conclude.