High-density single-nucleotide polymorphism (SNP) map in the 96-kb region containing the entire human DiGeorge syndrome critical region 2 (DGCR2) gene at 22q11.2

We constructed a high-density single-nucleotide polymorphism (SNP) map in the 96-kb region containing the DiGeorge syndrome critical region 2 (DGCR2) gene at chromosome 22q11.2, a human counterpart of mouse seizure-related gene SEZ-12. A total of 102 SNPs were isolated from the region by systematic screening among 48 Japanese individuals: 9 SNPs in the 5′ flanking region, 3 in the 5′ untranslated region, 2 in the coding regions, 77 in introns, 7 in the 3′ untranslated region, and 4 in the 3′ flanking region. By a comparison of our data with SNPs deposited in the dbSNP database in the National Center for Biotechnology Information, 80 SNPs (78.4%) were considered to be novel. The ratio of transition to transver-sion was 3.08 : 1. In addition, eight other types of genetic variations (one GA dinucleotide polymorphism and seven insertion/deletion polymorphisms) were discovered. The high-resolution map that we constructed will be a useful resource for analyzing gene scans of complex diseases mapped to this local segment on chromosome 22.