The results showed that the OR value of ITP susceptibility of TT genotype relative to CC genotype in the SNP1858 polymorphism of PTPN22 gene was 5.01, with 95%CI (1.81, 13.86) and p = 0.002, indicating the risk of ITP in the population with TT genotype was higher than that in the population with CC genotype. Here, PTPN22 is linked to autoimmune thrombocytopenic purpura.