nterleukin-17F rs763780 (7488A/G) gene polymorphism obviously affecting the expression and activity of
IL17F and may affect primary immune thrombocytopenia (PIT) susceptibility and its clinical features in Egyptian
children and adults. 105 ITP patients divided into (63 pediatric and 42 adult patient) and 112 age and sex
matched healthy controls were enrolled in this case control study. All patients were subjected to history taking;
clinical examination, CBC, bone marrow aspiration and genotyping of IL17F rs763780 polymorphism by (PCRRFLP)
technique. Our results revealed significant decrease in the mutant heterozygous genotype AG and also in
IL-17F mutant allele G frequency in ITP patient group and associated with increased risk for ITP compared with
the control group (P=0.04 and P=0.005 respectively). Furthermore, the mutant allele G frequency was significantly
decreased in childhood onset than adult onset ITP (OR=0.31, P=0.02) and also was significantly
lower in chronic ITP when compared with newly diagnosed and persistent ITP (P=0.005). Patients with the AA
genotype showed severe thrombocytopenic state at diagnosis than those with the AG genotype (P=0.04). We
concluded from our results that interleukin-17F rs763780 (7488A/G) polymorphism is strongly correlated with
susceptibility and severity of ITP.