Beta Thalassemia In Different Tribal Population In West Bengal, India

The Thalassemias are a group of anemia that results from a genetic defect whch reduces the rate of synthesis of normal globin chains. Beta Thalassemia results in severe microcytic, hypochromic, haemolytic anaemia among affected patients. It has emerged as one of the most common health problems among the tribal populations in West Bengal. A project entitled, “Status of Prevalence and Awarness Among Thalassaemia Population: Special reference to various tribes belonging in different Districts of West Bengal” has been sanctioned by the Department of Biotechnology, Govt. of India(BT/PR10336/SPD/24/293/2007). This study is aimed to observe the spectrum of various beta mutations among the tribes. In the screening schedule thalassemia awarness programme was conducted in various rural areas of West Bengal. We mainly confronted with the Sardar tribes in extreme south of West Bengal. In North Bengal there were Toto, Rabha, Oraon, Munda, Toppo, Baraik, Nagbanshi, Khalko, Kheria, Kerketta and Soren.

In the year 2009–2010, 1289 tribes were screened. Mass awarness programme were followed by collection of peripheral blood samples in EDTA vials and transported to the laboratory in ice packs. NESTROFT was done on spot using 0.36% Saline Buffer solution (Sodium chloride, Sodium dihydrogen phosphate, Disodium hydrogen Phosphate). Complete Blood Count was performed within 24 hours of collection. HPLC (High Performance Liquid Chromatography) was done to identify the beta samples. DNA was extracted from the blood of beta carrier and beta major and subjected to ARMS (Amplification Refractory Mutation System) PCR (Polymerase Chain Reaction) to detect the point mutations. Result:

Molecular Characterization of Beta globin gene mutations among these tribes have confirmed the presence of the following mutations: IVS-1 nt5 (G>C), IVS-1 nt1(G>T), codon 15 (G>A), codon 26 (G>A), the mutation which leads to HbE, codon 19 (A>G), codon 17 (A>T), -28 (A>G). The most common mutation observed among Totos and Rabhas were codon 26 (G>A) of North Bengal. The prevalence of Beta carrier among them is negligible. The mutation IVS-1 nt5 (G>C) is prevalent among the Oraon, Nagbanshi and Sardar tribes of Bengal. The other mutations which are present among them are codon 15 (G>A) and codon 30 (G>C). There are two codon 17 (A>T) and one -28 (A>G) mutations which are present among Mundas. The rest of them are mutation IVS-1 nt5 (G>C). In few cases presence of sickle cell anemia was observed. Our results have added to the existing data on the common beta globin gene defects which are prevalent among the general population of West Bengal, India.

No relevant conflicts of interest to declare.