A total of 454 variants were found in the coding exons of the 17 genes, including 380 RVs (MAF ≤ 1% in both EAs and AAs), and 74 common variants (MAF > 1% in at least of one of the two populations). As expected, AAs had more rare variants than EAs (Table 2). Genes with longer cDNA tend to have more exonic variants (r=0.87, P=4.9×10−6). However, some genes are less conserved than others, although they have similar length of cDNA. Among these 454 variants, 61.5% were already in dbSNP version 137, and the transition/transversion ratio (Ti/Tv) was 3.50. The Ti/Tv is consistent with the results from the 1000 Genomes Exon Pilot Project (Marth et al., 2011), indicating low false-positive variant calling from our sequencing results. In addition to these 380 exonic RVs, eight RVs were found in introns within 5 bp of a splice junction.
