Frequency of Human Platelet Antigens (HPA-2/3/5) Polymorphism in Iranians Evaluated by RFLP-PCR

ackground: Knowing the human platelet antigens (HPA) and genes frequency in different populations is important not only for population studies but also for clinical transfusion practice. HPA genes frequency in Iran is not evaluated, so we investigated the HPA-2, HPA-3, and HPA-5 frequency and their polymorphism. DNA from 120 Iranians (99 Iranian blood donors and 21 patients with platelet refractoriness) was isolated from peripheral blood mononuclear leucocytes and tested by restricted fragment length polymorphism analysis (RFLP). The frequency of HPA phenotypes was determined as follows: (in donors) HPA-2a/2a:75.4%, HPA-2a/2b:24.8%, HPA-3a/3a:8.1%, HPA-3a/3b:70.7%, HPA-3b/3b:21.2%, HPA-5a/5a:99 % and HPA-5a/5b:1%; (in patients) HPA-2a/2a:66.7%, HPA-2a/2b:33.3%, HPA-3a/3a:23.8%, HPA-3a/3b: 47.6%, HPA-3b/3b:28.6%, HPA-5a/5a:90.5%, and HPA-5a/5b: 9.5%. Frequency of genotypes evaluated by RFLP were as below: HPA-2a=0.87, HPA-2b=0.13, HPA-3a =0.28, HPA-3b=0.72, HPA-5a=0.99, and HPA-5b=0.01 in both donors and patients. HPA gene frequencies observed in Iranians were in the range obtained in previous studies but not exactly equal to other populations. It might be due to their relations with other populations. There was not any significant difference between two groups in this study.