Natural radioactivity
and human mitochondrial DNA mutations

Lucy Forster*,,, Peter Forster,§, Sabine Lutz-Bonengel¶, Horst Willkomm, and Bernd Brinkmann*

* Institute of Legal Medicine, University of Münster, 48129 Münster, Germany;  Molecular Genetics Laboratory, McDonald Institute, University of Cambridge, Cambridge CB2 3ER, England;  Alleppey, Kerala, 689580 India; ¶ Institute of Legal Medicine, University of Freiburg, 79104 Freiburg, Germany; and  Institute of Pure and Applied Nuclear Physics, University of Kiel, 24098 Kiel, Germany

Edited by Henry C. Harpending, University of Utah, Salt Lake City, UT, and approved August 9, 2002 (received for review July 5, 2002)

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.

The full text and charts of this article can be found here at the National Academy of Sciences of the United States of America..