Five SNPs, which are evenly distributed in the POMC region (average inter-marker distance: 3,860 bp), were selected from the NCBI dbSNP database (http://www.ncbi.nlm.nih.gov/SNP) (Table 2). Of these SNPs, two (rs6719226 and rs6545976) are in the upstream region, one (rs3769671) is in intron 1, one (rs6713532) is in intron 2, and one (rs1866146) is in the downstream region. As an additional measure of SNP coverage, we downloaded the HapMap CEU and YRI genotype data of SNPs located in the POMC gene region (chr2:25234077–25249516) (only nine SNPs, including the five SNPs we studied, with minor allele frequency > 2%), and then we evaluated whether these five SNPs can capture most information from the other four SNPs using the Tagger program in Haploview 4.0 (29). These five SNPs gave a mean r2 of 0.70 with the nine HapMap SNPs in the CEU (CEPH Europeans) population and 0.85 with the nine HapMap SNPs in the YRI (Africans) population. Thus, these five SNPs can potentially capture most of the genetic information of all other markers in the POMC region.
