The Prevalence Of Hbb Mutations Among The Transfusion-Dependent And Non Transfusion-Dependent Hb E/Beta-Thalassemia Children In A Tertiary Center Of West Bengal, India

Hb E (HBB: c.79G>A)/beta-thalassemia (Hb E/beta-thal) is responsible for nearly half of all the different kinds of severe beta-thal. This disorder is characterized by a wide range of clinical variability ranging from mild, asymptomatic non transfusion-dependent thalassemia (NTDT) to severe transfusion-dependent thalassemia (TDT). The aim of the present study was to determine the prevalence of different beta-globin gene (HBB) mutations in Hb E/beta-thal subjects and their potential role in transfusion dependence. One hundred and ten consecutive children with Hb E/beta-thal attending the Pediatric Department of Burdwan Medical College, Burdwan, West Bengal, India were enrolled. Based on hemoglobin (Hb) electrophoresis or high-performance liquid chromatography (HPLC), patients were recruited and later beta-globin gene sequencing was done to find out the prevalence of different HBB mutations. Transfusion-dependent thalassemia was seen in 42 children (38.2%), while NTDT was seen in 68 children (61.8%). A total of 10 different beta-globin mutant alleles were characterized. The most frequent mutation on the beta-globin gene was IVS-I-5 (G>C) (HBB: c0.92+5G>C) in both groups. The beta-globin gene mutations alone cannot determine transfusion dependence among the Hb E/beta-thal patients.