Characterization of a Functional Polymorphism in the 3' UTR of SLC6A4 and its Association With Drinking Intensity
Alcoholism: Clinical and Experimental Research Published Online: 20 Nov 2008

The propensity for severe drinking is hypothesized to be regulated by differential expression of serotonin transporter gene (SLC6A4) in the human brain. The SLC6A4 promoter region 5-HTTLPR has been examined previously as a candidate polymorphic variant associated with severe drinking.

In this study, we investigated whether other SLC6A4 single nucleotide polymorphisms (SNPs) are associated with drinking intensity among treatment-seeking alcoholics and whether these polymorphic variants result in differential SLC6A4 expression levels.

One of the 6 polymorphisms we examined, rs1042173 in the 3' untranslated region (3'-UTR) of SLC6A4, showed a significant association with drinking intensity. The G allele carriers for rs1042173 were associated with significantly lower drinking intensity (p = 0.0034) compared to T-allele homozygotes. In HeLa cell cultures, the cells transfected with G allele showed a significantly higher mRNA and protein levels than the T allele-transfected cells.

These findings suggest that the allelic variations of rs1042173 affect drinking intensity in alcoholics possibly by altering serotonin transporter expression levels. This provides additional support to the hypothesis that SLC6A4 polymorphisms play an important role in regulating propensity for severe drinking.

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Request Reprnit E-Mail: ming_li@virginia.edu

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