Gene frequencies of the human platelet antigen-3 in different populations

Human platelet antigen (HPA) systems consist of more than 12 biallelic antigen polymorphisms in which a base pair substitution leads to change in an amino acid of a glycoprotein expressed on the platelet. HPA-3 is a HPA that is mentioned for possible induction of neonatal alloimmune thrombocytopenia, posttransfusion purpura, and platelet refractoriness. A summary is presented of previous reports on the gene frequencies of HPA-3 among different populations. The frequency of HPA-3a and -3b ranges from 0.50 to 0.61 and 0.38 to 0.50, respectively. A significant correlation between the population ethnicity and the gene frequencies was detected in this study. However, it is quite difficult to use HPA-3 gene as a gene marker to determine the similarity of gene population in different populations. In addition, the comparison of the heterogenicity of HPA-3 frequencies to another well-known HPA gene, HPA-1 gene demonstrates that there is a greater variation in HPA-3 frequencies than in the HPA-1 gene. There was no significant correlation between the incidence of autoimmune thrombocytopenia disorder and the HPA-3 gene polymorphism pattern.