DQ-DP region on human chromosome 6, SNP markers, and genomic structure of BRD2 (RING3). Top, arrows along the chromosome denote genes, which are labeled, and their direction of transcription; asterisks denote SNP markers. Bottom, BRD2 (RING3) gene exploded to show the relation of the exonic sequences with SNPs, the CA repeat microsatellite, and other DNA variations.