Molecular pathogenesis and clinical variability of homozygous β 0-thalassemia in populations of Jammu region of J&K state (India)

Abstract

This study was undertaken to evaluate the variation in the clinical presentation of homozygous β 0-thalassemia from severe disease to a beta-thalassemia intermedia phenotype and to look for the contribution of associated factors in this variation of clinical course. Type of β 0-thalassemia mutations, associated α-thalassemia, and Xmn I polymorphism in the gamma globin gene, which are known to affect the clinical course of the disease, were investigated from 15 homozygous β 0-thalassemia patients comprising 11 patients with β-thalassemia major and 4 patients with β-thalassemia intermedia. Transfusion dependency and the age at which the patient presented with symptoms were used to assess the degree of clinical severity of these patients. Three different β 0-thalassemia mutations viz. CD 41-42 (-TTCT), CD 8-9 (+G) and 619bp deletion, were encountered among the 30 βthalassemia alleles. It was observed that the type of β 0-thalassemia mutations was not different between the two groups, but co-inheritance of one or more α-gene deletions and the presence of the XmnI polymorphism were associated with lesser severity of the disease.