Genetic diversity of hemoglobinopathies, G6PD deficiency, and ABO and Rhesus blood groups in two isolates of a primitive Kharia Tribe in Sundargarh District of Northwestern Orissa, India

Abstract

Tribal communities constitute about 8.2% of the total population of India. Their health needs are even larger than elsewhere in India; this study investigates the genetic diversity in relation to hemoglobinopathies, G6PD deficiency and, ABO and Rhesus (D) blood groups in two sects, i.e. Dudh (converted Christian) and Dhelki (Hinduised) Kharia, a primitive tribe in Sundargarh district of Orissa in Central-Eastern India. A randomized screening of 767 Kharia tribals (377 males and 390 females) belonging to all age groups and both sexes was done. Laboratory analysis was carried out following the standard methodology and techniques. Contrasting differences were observed in the frequency of hematological genetic disorders such as β-thalassemia, sickle cell, hemoglobin E, G6PD deficiency, ABO and Rhesus (D) blood groups between the two subgroups. Dudh Kharia had no hemoglobin variant allele other than the high prevalence of β-thalassemia trait (8.1%), whereas, their counterpart Dhelki Kharia had the high prevalence of sickle cell allele (12.4%), hemoglobin E allele (3.2%), and β-thalassemia allele (4.0%). Frequency distribution of hemoglobin variants between Dudh and Dhelki Kharia tribe was statistically highly significant (p < 0.001). High G6PD deficiency was detected 19.2% and 30.7% in Dudh Kharia and Dhelki Kharia, respectively (p < 0.001), the average being 24.4% in Kharia tribe. Kharia tribes show a trend for replacement of sickle cell gene with G6PD-deficiency gene as the clinical manifestations of G6PD deficiency are mild (do not result in a complete loss of enzyme activity) against the sickle cell disease with high morbidity and mortality. Rhesus (D)-negative blood group was 1.1% in Dudh Kharia and absent in Dhelki Kharia (p < 0.05). This study showed genetic isolation of the two sects of Kharia tribe. Antimalarial drugs administration needs to be done with caution. Hematological disorders pose a major health challenge having multifaceted implications in public health genetics.