Association of Br polymorphism of platelet GP Ia gene and immune thrombocytopenic purpura

Abstract

Studies on the molecular structure underlying Br(a)/Br(b) (HPA-5) platelet alloantigen show that a single base polymorphism at position 1648 on platelet mRNA coding for GP Ia results in a amino acid substitution at position 505 on the mature GP Ia which is associated with the two serologically defined Br types. While this polymorphism has no known effects on platelet function, the possible influence of this polymorphism in immune thrombocytopenia ITP is again unexplored. Therefore, the genotype frequency of Br polymorphism in ITP was compared with that of healthy general Korean population. Interestingly, there was a statistical difference (P=0.03) in genotype frequency of Br polymorphism. The association of Br(a)/Br(b) (HPA-5)genotype and occurrence of ITP may suggest the possible influence of genetic polymorphism on the pathogenesis of ITP.