New polymorphisms within human TAP2 in the ATP-binding domain and profiles of TAP polymorphism in Japanese.

Abstract

Four TAP1 alleles (0101, 0201, 0301 and 0401), and four TAP2 alleles (0101, 0102, 0103 and 0201) have been already identified in the Caucasian population. We investigated TAP1 and TAP2 polymorphisms in 106 healthy Japanese by PCR-low ionic strength single stranded conformation polymorphism (PCR-LIS-SSCP). Three of four TAP1 and all known TAP2 alleles were identified in these suhjects, and the allele frequencies of TAP1 were similar between the Japanese and the Caucasian populations, although those of TAP2 were different. Moreover, we found a new sequence variation at codon 577 (ATG→GTG:Met→Val) in the ATP-binding domain of the TAP2 gene. This variation was found in 12.4% of healthy Japanese (allele frequency: 6.6%), exhibited a strong linkage disequilibrium with DRB1* 0803-DQB1* 0601 and leaded to recognition of a new TAP2 allele, TAP2* Bky2 (allele frequency: 5. 1%).