Effect of high background natural radioactivity on human mitochondrial DNA in Ramsar, the north of Iran

Radioactivity is known to induce tumours, chromosome lesions, and mini-satellite length mutations, but also effects on the DNA sequence. Ramsar region, in the north of Iran with the highest background of natural radiation (226Ra) in the world, with a densely populated area, offers an opportunity to characterise radiation-associated DNA mutations. We sampled 30 individuals from this area and 15 cases from Tehran as controls. We sequenced their mtDNA and found multiple variations in multiple nucleotide positions in Ramsar inhabitants. 16519 and T > C were the most frequent NPS and variables in our study. In this preliminary investigation, we conclude that an elevated level of natural background radiation in Ramsar region had a significant effect on the control region of mtDNA. We think this is the first report from Ramsar in this field. Moreover, using molecular and biological pathways and study of gene expression to understand the cellular and molecular response of human mtDNA to low-dose radiation exposure is recommended.