A previous sib-pair linkage analysis of lnmaxalc in COGA found significant evidence for linkage (LOD = 3.5) on chromosome 4q21.3, near marker D4S2407 [6]. We were unable to replicate this finding in our dataset; however, we only had a subset of families and did not have the additional chromosome 4 microsatellite markers used in their study. Interestingly, our SNP-based analyses detected a weak signal in the same chromosome 4 region, suggesting that SNPs provided more information if indeed a true linkage signal exists. Instead, our peak LOD scores were found on chromosome 1, proximal to locations linked to other alcohol phenotypes [1].
