Identification of a novel mitochondrial DNA sequence variation within the human mitochondrial DNA Control Region in a population of Aegean population

Abstract

Objective: Environmental impacts, history as well as established cultural regulations, and many more other factors had shaped broadly diverse structure of human genetic patterns. A control region of human mtDNA has served as a good genetic determination marker in many fields such as evolutionary studies and forensic genetics. The allelic variations of mtDNA have been studied in many populations including Turkish populations. Previous studies in Turkish populations lacked large cohorts. In this study, non-coding hypervariable regions of human mitochondrial DNA with extended population of Turkish individuals from Aegean region have been investigated. Materials and Methods: To detect sequence variants in human mtDNA control region, 100 unrelated Turkish subjects were examined. Results: The outcomes revealed 13 variable sites in hypervariable region I (HVRI) and 20 variable sites in hypervariable region II (HVRII). Polymorphisms within HVRI were detected at the positions of 16173 (C>A) and 16175 (A>G) with the allelic variation frequencies of 53% and 60%, respectively. A novel nucleotide transversion from cytosine to adenine at 16173 position was detected. Only 35% of subjects were aligned with the Cambridge Reference Sequence for the poly-cytosine tract that locates between 303 and 309 nucleotides, whereas 60% of individuals had 8 and 15% of them had 10 cytosine polynucleotides. 263G and 73G polymorphisms were evaluated with higher frequencies for the HVSII region. Conclusion: Overall, results indicate that the determination of genotype distributions and allelic variations frequencies of human mitochondrial genome are significant to characterize admixture populations from different ethnic origins.