Genetic Risk Factors for Inhibitor Development in Patients with Hemophilia and Rare Bleeding Disorders

Inhibitor development is a lifelong challenge for patients with bleeding disorders who received replacement therapy. Most commonly, inhibitor formation was observed in hemophilia A patients but patients with rare bleeding disorders (RBD) especially patients with deficiency of factor XIII (FXIII) and factor V (FV) can develop an inhibitor against exogenous factors. Several factors considered as risk factors for inhibitor formations in these patients. Genetic risk factors are the main accused that can cause inhibitor formation in hemophilia patients but are less important in RBDs.For this review study, we searched MEDLINE and Web of Science databases for English sources and the following key words: hemophilia, inhibitor, rare bleeding disorder, rare inherited disorder, acquired hemophilia, acquired rare bleeding disorders, treatment complication, genetic in hemophilia, polymorphism in rare bleeding disorder, mutation in hemophilia and other required keywords.Hemophilia A (HA) patients who had large deletion, nonsense mutation or intron 22 inversion are more susceptible for inhibitor development. Gene polymorphisms in immune system are also considered as other risk factors in HA patients.