Gene frequencies of the HPA-1 to HPA-8w platelet antigen alleles in Taiwanese, Indonesian, and Thai

Human platelet antigen (HPA) systems consist of more than eight biallelic antigen polymorphisms in which a base pair substitution leads to change in an amino acid of a glycoprotein expressed on the platelet. HPA typing is essential in the diagnosis and treatment for a variety of diseases. We developed a polymerase chain reaction (PCR)-based method to detect HPA-1 through HPA-8w. In this method, the amplified PCR products were used to recognize the polymorphism after restriction enzyme digestions. Among 295 Taiwanese, 107 Indonesian, and 137 Thai subjects studied, HPA-1a, 2a, 4a, 5a, 6a, 7aw, and 8aw genes were present in every sample tested. HPA-1b, 2b, 4b, 5b, and 6b were rarely found among subjects. Only monomorphic HPA-7aw and 8aw alleles were noted in the samples. HPA-3a and 3b alleles showed frequencies of 0.595/0.405, 0.504/0.496, and 0.507/0.493 in Taiwanese, Indonesian, and Thai subjects, respectively. Our report is the first PCR-based method to detect most of the HPA antigen variants in Taiwanese, Indonesian, and Thai. The genomic typing results were also confirmed by direct sequencing for uncertain and some representative cases. The prevalence rates of HPA-1, 2, 3, 4, and 5 in this study were also consistent with other previous reports using different methods.