Thalassemia among the tribal communities of India

Abstract

Though the tribal communities constitute a major part of India, unfortunately they are highly vulnerable to many hereditary disorders causing high degree of morbidity and mortality. To map out thalassemia among the Indian tribes, an extensive review study was conducted from the literature published since last 20 years. Literature review shows that thalassemia and other haemoglobinopathies are highly prevalent (0.028-18%) among the tribal communities. Some types of deleterious mutation are restricted to some particular tribes. Such as tribes of Maharastrya and Gujrat have shown prevalence of 619bp deletion mutations in 49.2% and 45.5% carriers, respectively. HbS (codon 6A→T) mutant allele is widespread among many Indian tribes. HbE mutation among the Bodo Kachari of Assam is found to be the highest observed frequency in the world followed by the tribes of adjoining Tripura. The evidence of the hereditary persistence of rare HbF is also prevalent among the Indian tribes. In case of Gond in Central India, HbF levels varied as much as 42.55% with high G-gamma values. Since last 20 years the high frequencies of these mutant alleles is maintained by the tribal populations probably due to consanguinity and endogamous mating for a long period of time, along with ignorance, lack of awareness and conveyance, lowincome status and high cost of treatment make them vulnerable. Thus, action like community awareness, screening of carriers, establishment of prenatal diagnosis facilities, optimum treatment of thalassemia babies etc. should be taken immediately.