Other AUD associations for both Plains American Indians and Finnish Caucasians have been found for GAL, a gene encoding the neuroendocrine peptide galanin57 and HNMT, that encodes histamine N-methyltransferase, implicated in metabolism of histamine.58 An earlier study found that 5-HTR1B, encoding a serotonin receptor, was associated with antisocial alcoholism in both Finnish Caucasians and Southwestern American Indians.59 Finally, a sufficiently powered study looking at association and sib-pair linkage analyses of the functional OPRM1 polymorphism A118G Asn40Asp, rs1799971 with AUD produced similar negative findings in US Caucasians, Finnish Caucasians and Southwestern American Indians.60 There have only been a few other candidate gene studies of AUD and intermediate phenotypes for AUD conducted in AI with mixed results.47
