Natural radioactivity and human mitochondrial DNA mutations

Abstract

Radioactivity is known to induce tumors, chromosome lesions, and minisatellite length mutations, but its effects on the DNA sequence have not previously been studied. A coastal peninsula in Kerala (India) contains the world's highest level of natural radioactivity in a densely populated area, offering an opportunity to characterize radiation-associated DNA mutations. We sampled 248 pedigrees (988 individuals) in the high-radiation peninsula and in nearby low-radiation islands as a control population. We sequenced their mtDNA, and found that the pedigrees living in the high-radiation area have significantly (P < 0.01) increased germ-line point mutations between mothers and their offspring. In each mutation case, we confirmed maternity by autosomal profiling. Strikingly, the radioactive conditions accelerate mutations at nucleotide positions that have been evolutionary hot spots for at least 60,000 years.

Preconception exposure to mutagens: medical and other exposures to radiation and chemicals

“…Although no excess of infant mortality has been seen, a possibly higher increased rate of Down syndrome, but not other congenital malformations, has been documented (Jaikrishan et al 1999). No excess of mitochondrial DNA mutations were seen in exposed women (Forster et al 2002). & A second type of exposed cohort consists of the Japanese survivors of the American atomic bombs as a prototype for nuclear bomb tests, as mentioned above (Neel and Schull 1991;Schull 2003), and of other events or accidents involving ionizing radiation, e.g., in power generation disasters in Chernobyl and after the Fukushima, Japan earthquake and tsunami of 2011, and weapons testing in Russia (Dubrova et al 2002;Dubrova 2003).…”

Mealybug as a Model for Studying Responses to High Doses of Ionizing Radiation

“…However in a separate study, no significant difference was observed between the high-level exposed population and control population (Cheriyan et al, 1999). In addition, a recent report on mitochondrial DNA sequence analysis revealed that there is an increased rate of mitochondrial DNA mutations in the 'exposed population' than in the control population (Forster et al, 2002). Clearly more detailed studies are required to be done to conclusively associate genomic effects of chronic exposure to IR.…”

Study of stillbirth and major congenital anomaly among newborns in the high-level natural radiation areas of Kerala, India

“…There were reports of a higher prevalence (12/ 12,918 in HLNRA vs. 0/5,938 in control area) of Down syndrome in HLNRA (Kochupillai et al 1976) and a higher frequency of mitochondrial DNA mutation (22/595 in HLNR vs. 1/200 in NLNR; P<.01, likelihood ratio chisquare) in saliva samples (Forster et al 2002). Down syndrome report (Kochupillai et al 1976) was criticized for design issues (Sundaram 1977).…”