Genetic characterisation of the North-West Indian populations: analysis of mitochondrial DNA control region variations

Background: Human mitochondrial DNA presents several interesting characteristics, making it a favourable tool in the field of molecular anthropology, medical genetics, population history, and forensic science. Aim: The present study investigated the mitochondrial DNA (mtDNA) control region variations in diverse ethnic groups of North-West India for which population data is insufficient. Subjects and methods: The complete mtDNA control regions of 197 unrelated (for up to three generations) healthy individuals belonging to different ethnic groups of North-West India were sequenced. The haplotype frequencies, haplogroup distribution, and pairwise F_ST values between the studied and other worldwide populations were generated to study patterns of variation in human mtDNA. Results: The results ascertained high gene diversity (0.998) in the studied maternal lineages, identifying 166 distinct haplotypes, of which 158 were unique and characterised by 117 variable sites. Three haplogroups: M3, M30, and U7 were observed to be the most prevalent, and phylogeographically a total of 55.86% of sequences were characterised into South Asian, followed by West Eurasian (40.18%) and East Asian (3.96%), ancestry haplogroups. Pairwise genetic differentiation comparisons revealed maternal homogeneity in the studied groups. No population substructure was detected within the North-West Indian populations. Conclusion: The results of this preliminary study will contribute to an existing database of mtDNA variations of the Indian population and facilitate prospective studies investigating population genetics and human diseases.