Prevalence of α(+)-Thalassemia in the Scheduled Tribe and Scheduled Caste Populations of Damoh District in Madhya Pradesh, Central India.

This study was carried out to ascertain the allelic frequency of α(+)-thalassemia (α(+)-thal) in Scheduled caste and scheduled tribe populations of the Damoh district of Madhya Pradesh, India. Random blood samples of Scheduled tribe (267) and Scheduled caste (168), considering the family as a sampling unit, were analyzed for the presence of the -α(3.7) (rightward) (NG&#95;000006.1: g.34164&#95;37967del3804) and -α(4.2) (leftward) (AF221717) deletions. α(+)-Thal was significantly higher in the Scheduled tribals (77.9%) as compared to the scheduled caste population (9.0%). About 58.0% scheduled tribals carried at least one chromosome with the -α(3.7) deletion and 20.0% scheduled tribals carried the -α(4.2) deletion. Frequency for the -α(3.7) allele was 0.487 in the scheduled tribal populations in comparison to 0.021 in scheduled castes. Allelic frequency for -α(4.2) was 0.103 and 0.024, respectively, in the above communities. No Hardy-Weinberg equilibrium for α-thal gene (p < 0.05) was detected in the tribal population, indicating the presence of selection pressures in favor of α-thal mutation and adaptation.