Polymorphism of HLA-DR2,DQw1 haplotypes in Asian Indians.

We examined the polymorphism of DR2,DQw1 haplotypes in Epstein-Barr virus-transformed B-lymphoblastoid cell lines (HTCs) and unrelated (32 Canadian Caucasians and 24 Asian Indians) individuals by restriction fragment length polymorphism (RFLP) and oligonucleotide typing. The data demonstrate that three subtypes of DR2,DQw1 haplotypes, DRw15(B1.1501).DQw6a(A1.0102,B1.0602),DRw15(B1.1502). DQw6b(A1.0103,B1.0601), DRw16(B1.1601).DQw5(A1.0102,B1.0502) are present in HTCs and Canadian Caucasians. Of these, DRw15(B1.1501).DQw6a (A1.0102,B1.0602) haplotype was present in majority (81.3%) of Caucasians. Among Asian Indians, this haplotype was present only in one DR2,DQw1-positive individual. In addition, three new haplotypes representing different combinations of DRB1, DQA1 and DQB1 genes were demonstrable in Asian Indians. These new haplotypes are DRw15(B1.1501).DQw6b(A1.0103,B1.0601),DRw15(B1.1501). DQw5(A1.0102,B1.0502), and DRw15(B1.1501).DQw6c(A1.0102, B1.0601). The most frequent haplotypes among Asian Indians were DRw15(B1.1502).DQw6b(A1.0103,B1.0601) and DRw15(B1.1501). DQw6b(A1.0103,B1.0601). The distribution of subtypes of DR2,DQw1 haplotypes in Asian Indians was significantly different from that in Canadian Caucasians. The results in the present study have important implications for HLA and for HLA-disease associations.