HLA-DPB1 alleles in a population from south China.

Using the polymerase chain reaction (PCR) and hybridization with oligonucleotide probes, we analyzed the distribution of DPB1 alleles in 99 healthy unrelated individuals from the city of Guangzhou (Canton), South China. Twelve different DPB1 alleles were found in this panel. The most common allele was DPB10501 (62.6%). Other major alleles detected included DPB102 (DPB10201 and DPB10202), DPB11301, DPB10401, and a recently described allele, designated DPB12101. The hybridization pattern of DPB12101 showed that this allele shared sequences with DPB10301 and DPB10601 in the A and F hypervariable regions, while the C, D, and E regions were identical to those of DPB10202. DPB12101 was observed in 11% of the subjects tested. It was found to be in strong linkage disequilibrium with DRB11202. In family studies, segregation of the haplotype DRB11202, DRB30301, DQA10601, DQB10301, DPB12101 was observed. The second exon of DPB12101 was sequenced from codon 8 to codon 90 and the sequence, inferred from the pattern of hybridization, was confirmed. DPB10301, DPB10402, DPB10101, DPB11401, DPB11901, and another recently recognized allele, now designated DPB12401, were detected with low frequencies. DPB12401 had the same hybridization pattern as DPB10501 except for a probe that matches codons 85-90. In this region, DPB12401 encoded the amino acid sequence GPMTLQ instead of EAVTLQ as in DPB1*0501.