Abstract: Objective To detect the polymorphism of platelet specific antigen (HPA) -1-6/17 gene in patients with thrombocytopenia (ITP) in Qingdao, and to analyze its relationship with genetic susceptibility to ITP disease. Methods 126 ITP patients diagnosed and treated in the Affiliated Hospital of Qingdao University from 2013 to 2016 were selected as the research objects, and 120 healthy people in the hospital during the same period were selected as the control group. Genomic DNA was extracted by QIAamp DNA Blood Mini Kit , and HPA-1-6/17 was genotyped by PCR-SSP. Results The HPA gene polymorphism of ITP patients and normal population in Qingdao conformed to Hardy-Weinberg law（P>0.05）. There was no significant difference in genotype frequencies and alleles of HPA1-2, HPA4-6 and HPA17 between ITP group and normal people（P>0.05）. There were significant differences in HPA-3 genotype and allele frequency between the two groups（P<0.05）. Compared with the control group, the frequency of HPA-3 aa genotype in ITP group was significantly lower（P<0.05）, and the frequency of HPA-3 bb genotype was significantly higher（P<0.05）. The frequency of HPA-3a gene in ITP patients was significantly lower than that in control group（P<0.05）, and the frequency of HPA-3b gene was significantly higher than that in control group（P<0.05）. Logistic regression analysis showed that the increase of frequency of HPA-3b gene was associated with ITP genetic susceptibility（P<0.05）. Conclusion sHPA-3 system is related to the occurrence of ITP. The frequency of HPA-3b gene in ITP patients is significantly higher than that in control group, which may be a susceptible factor for ITP.

Key words: Thrombocytopenia, Platelet specific antigen, Genetic susceptibility, Genetic polymorphism