(rs16969968 and rs8040868) tag the locus 1 signal defined by Saccone et al. (2009a, b, 2010). One SNP (rs11637630) tags locus 2, and two SNPs (rs680244 and rs514743) tag locus 3. The other SNPs appear to be separate LD signals from the three identified major loci. LD for five of the SNPs is available on Hapmap, with r2 ranging between 0.286 and 0.802, shown in Fig. 1. The correlation between SNPs in the sample selected for the mixture analyses was generally much lower, with r2 not exceeding 0.22, hence the ten SNPs could be included in the analyses simultaneously without the risk of instability of parameter estimates due to multicollinearity. Minor allele frequencies in the sample ranged between 0.235 and 0.402. SNPs were scored 0, 1, and 2 indicating the number of minor alleles.
