Molecular pathogenesis and clinical variability of homozygous β⁰-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 β⁰-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 β⁰-thalassemia mutations, associated α-thalassemia, and XmnI polymorphism in the gamma globin gene, which are known to affect the clinical course of the disease, were investigated from 15 homozygous β⁰-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 β⁰-thalassemia mutations viz. CD 41–42 (−TTCT), CD 8–9 (+ G) and 619 bp deletion, were encountered among the 30 beta-thalassemia alleles. It was observed that the type of β⁰-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.

Keywords:

• HOMOZYGOUS
• THALASSEMIA
• INTERMEDIA
• GLOBIN