Fig 1. DPP4 gene locus on human chromosome 2q24.2 and tagging SNPs.

The DPP4 gene is located on the reverse strand, consists of 26 exons and 25 introns, and spans 82.3 kb from nucleotide position 162,848,755 to nucleotide position 162,931,052 (Ensembl reference data). A region from 5 kb upstream to 5 kb downstream of the gene was analyzed. This genomic region does not overlap with other known gene loci. The 44 common HapMap SNPs of the locus are shown (minor allele frequencies ≥0.05). The locations of the 14 tagging SNPs are highlighted by white circles. HapMap-derived linkage disequilibrium data (r²x100) are indicated in shaded diamonds (black diamond without value stands for r² = 1.0). SNP–single nucleotide polymorphism.