Three hundred twenty-six genetic variations in genes encoding nine members of ATP-binding cassette, subfamily B (ABCB/MDR/TAP), in the Japanese population.

We screened DNAs from 48 Japanese individuals for single-nucleotide polymorphisms (SNPs) in nine genes encoding components of ATP-binding cassette subfamily B (ABCB/MDR/TAP) by directly sequencing the entire applicable genomic regions except for repetitive elements. This approach identified 297 SNPs and 29 insertion/deletion polymorphisms among the nine genes. Of the 297 SNPs, 50 were identified in the ABCB1 gene, 14 in TAP], 35 in TAP2, 48 in ABCB4, 13 in ABCB7, 21 in ABCB8, 21 in ABCB9, 13 in ABCB10, and 82 in ABCB11. Thirteen were located in 5' flanking regions, 237 in introns, 37 in exons, and 10 in 3' flanking regions. These variants may contribute to investigations of possible correlations between genotypes and disease-susceptibility phenotypes or responsiveness to drug therapy.