Molecular characterization of thalassemia intermedia in Indians.

Thalassemia intermedia shows considerable heterogeneity. The purpose of this study was to evaluate the prevalence and effect of common molecular determinants in thalassemia intermedia. In 73 cases of thalassemia intermedia, the possible molecular basis was co-existent a-deletions (n=16/50), homozygous XmnI polymorphism (n=17/50), both factors (n=3/50), and milder beta-alleles (n=9/50) in homozygous beta-thalassemia (total 50 cases). In heterozygous beta-thalassemia, alphaalphaalphaanti-3.7 triplication was the predominant factor (14/23 cases).