The Effect of Xmn -1 Polymorphism and Coinheritance of Alpha Mutations on Age at First Blood Transfusion in Iranian Patients with Homozygote IVSI-5 Mutation.

Background : Thalassemia syndromes are the most prevalent hereditary hemoglobinopathies in the world. Iran is located on the thalassemia belt.  In this study, the effect of Xmn -1 polymorphism and coinheritance of alpha mutations on age at first transfusion and also transfusion interval in Iranian thalassemic patients with homozygous IVSI-5 mutation were assessed. Materials and Methods : In this retrospective cross-sectional study 154 transfusion dependent thalassemia (TDT) patients (140 patients with β-thalassemia major and 14 cases with β-thalassemia intermedia) who were homozygote of IVSI-5 mutation have been participated. Blood samples were collected from participants using EDTA containers for genomic DNA analysis. DNA extraction and amplification-refractory mutation to determine the Xmn -1 polymorphism were performed. Multiplex PCR was performed to identify alpha globin deletions.  Results: The mean age of participants was 29±7, 58 of them were male and 96 were female. A significant relation between presence of Xmn -1 polymorphism and age at receiving first transfusion was detected. Coinheritance of alpha thalassemia mutation does not have significant effect on age at first transfusion or transfusion interval. Conclusion : Presence of Xmn -1 polymorphism can delay the onset of transfusion in patients with homozygote IVSI-5 mutation.