DNA methyltransferase 3B (DNMT3B -579G>T) promotor polymorphism and the susceptibility to pediatric immune thrombocytopenic purpura in Egypt.

Idiopathic thrombocytopenic purpura (ITP) is an autoimmune disease characterized by increased platelet destruction. Although the etiology of ITP remains unclear, it is accepted that both environmental and genetic factors play an important role in the development of the disease. The present study aimed at exploring a novel molecular determinant that may influence the susceptibility and course of ITP in Egyptian children. To achieve our aim, genotyping of DNMT3B -579G>T promotor polymorphism by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) assay. The current study was conducted on 140 ITP patients and 150 age and gender matched healthy controls. The results obtained revealed that DNMT3B -579 TT homotype was significantly higher in ITP patients and conferred almost three fold increased risk of ITP (OR=3.16, 95%CI=1.73-5.79). There was no statistically significant difference between ITP patients with wild or mutant genotypes as regards their clinical or laboratory data. Furthermore, there was no statistical difference in the distribution of DNMT3B -579G>T genotypes between acute and chronic ITP patients. In conclusion, DNMT3B -579G>T promotor polymorphism represents a novel genetic risk factor for ITP but not a predictor for tendency to chronicity in pediatric ITP in Egypt.