Chromosome 4, which has been implicated in a previous linkage study of maximum drinks, did not pass our threshold for linkage evidence in the first stage of our primary analysis, but additional analyses of this chromosome indicated modest evidence for both linkage and association. In Saccone et al. [1] linkage to maximum drinks was found at marker D4S2407 on chromosome 4, which is located at 104.75 cM according to the Marshfield genetic map. Build 35.1 of the NCBI physical map puts this marker at approximately 97.60 Mb. This is near our linkage LOD score of 2.14 at rs1378876 located at 97.25 Mb on the same build (97.35 Mb on the GAW Illumina map). Hence, our supplementary analysis indicates some support for prior results on chromosome 4; however, our primary, two-stage analysis of the full genome does not support chromosome 4 and instead points to chromosome 7 as the strongest candidate for harboring a quantitative trait locus. The contrast between the chromosome 4 results for our primary analyses reported here and previous COGA findings is likely explained in part by the
