RESUMO
Idiopathic (immune) thrombocytopenic purpura (ITP) is a heterogeneous clinical disorder characterized by immune-mediated platelet destruction. Epigenetic changes in gene expression, including DNA methylation and histone modifications, might contribute to autoimmunity. Polymorphisms of the DNA methyltransferase 3B (DNMT3B) gene may influence DNMT3B activity on DNA methylation and increase the susceptibility to several diseases. The current study investigated the association between a single nucleotide polymorphism (SNP) in the promoter of DNMT3B gene and the risk for ITP in pediatric Egyptians. DNMT3B SNP was genotyped by PCR-restriction fragment length polymorphism in 71 pediatric ITP patients and 82 healthy controls matched for age and sex. The C/C wild genotype was not detected in ITP patients or in the controls. The frequencies of the T/T and C/T genotypes were 93.9 and 6.1% in the controls and 91.5 and 6.1% in ITP patients, respectively. There was no significant difference in either genotypes or allelic distribution between ITP patients and the controls. In conclusion, this polymorphism was almost equally distributed between ITP patients and the controls. These results demonstrated that this SNP may not be used as a stratification marker to predict the susceptibility to childhood ITP in Egypt.
