Mitochondrial DNA studies in the South African Indian population

The polymorphisms of mitochondrial DNA (mtDNA) for the restriction enzymes HpaI, BamHI, HaeII, MspI, AvaII, and HincII were studied in a sample of 147 unrelated Indian individuals from South Africa, who were subdivided according to religion and language into four groups, namely, Tamil, Hindi, Gujerati and Moslem. They were found to be monomorphic with the enzymes BamHI, and HaeII, and little variation was observed with the enzymes MspI and HincII. Six individuals were found to contain the non-Caucasoid HpaI morph, HpaI-3, which is found more commonly in indigenous African populations. This suggests that some flow of maternal genes from indigenous African populations into the Indian population may have occurred. Despite these interactions, Indians in South Africa display very little mtDNA variation (F = 0.77) when compared with those living in Nepal (F = 0.35) and New Delhi (F = 0.51). When compared with other Caucasoid populations, Indians are more homogenous in their genetic structure, which may be attributable to the high level of inbreeding among them, due to strict caste endogamy and certain religious customs that are still practised by the majority of Indians today.