XmnI POLYMORPHISM AND DISEASE SEVERITY IN PATIENTS WITH BETA THALASSEMIA FROM NORTHERN PAKISTAN
AbstractBackground: Thalassemia is a heterogeneous disorder and several genetic factors influence the severity of thalassemia. An accurate and early diagnosis of a mild thalassemia genotype helps to avoid unnecessary transfusion and its complications. The aim of this study is to identify the association between XmnI polymorphism and disease severity in patients with β-thalassemia from northern Pakistan. Methods: The cross sectional study was conducted at the Department of Haematology, Armed Forces Institute of Pathology (AFIP) Rawalpindi, from September 2006 to June 2009. A total of 90 subjects including 30 with thalassemia major, 30 with thalassemia intermedia and 30 normal individuals were studied. DNA from each subject was tested for 15 β-thalassemia mutations and the presence of XmnI polymorphism using Amplification Refractory Mutation System and Restriction Fragment Length Polymorphism respectively. Results: One normal and one thalassemia major subject were found to be positive for homozygous and heterozygous XmnI polymorphism respectively. Among the thalassemia intermedia group, XmnI polymorphism was found in 12/30 patients, of whom 10 were homozygous and 2 were heterozygous for it. Conclusion: XmnI polymorphism is an important genotypic factor in Pakistani population for making a prospective diagnosis of thalassemia intermedia and predicting the severity of the disease.Keywords: Thalassemia intermedia, XmnI endonuclease, Restriction Fragment Length Polymorphism, Northern Pakistan
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