Six areas of the genome provided LOD scores suggesting evidence for linkage to the FIRST FIVE SRE phenotype in this Indian population. One location was on chromosome 6 at 147 cM that had a LOD score of 3.86. A previous study in this Indian population also found suggestive evidence for linkage on chromosome 6q24-25 for “any drug dependence/regular tobacco use” as well as Body Mass Index suggesting genes in that location may be associated with risk for substance dependence and other consumption-related phenotypes (Ehlers and Wilhelmsen, 2007). Additionally, this locus on chromosome 6 is centered only 2 cM from the location of the mu opioid receptor gene OPRM1. In an association study in this Indian population several SNPs in OPRM1 were found to be significantly associated with a level of response to alcohol phenotype (Ehlers et al., 2008b). Endorsing the expectation of a more intense response to alcohol after imbibing 2–3 drinks was significantly associated with having at least one minor allele for at least one of 7 SNPs (p<0.01) in the OPRM1 receptor gene.
