Gene that once aided survival in the Arctic found to have negative impact on health today

http://www.eurekalert.org/pub_releases/2014-10/cp-gto101614.php

PUBLIC RELEASE DATE: 23-Oct-2014

Contact: Mary Beth O'Leary
Cell Press
Gene that once aided survival in the Arctic found to have negative impact on health today

In individuals living in the Arctic, researchers have discovered a genetic variant that arose thousands of years ago and most likely provided an evolutionary advantage for processing high-fat diets or for surviving in a cold environment; however, the variant also seems to increase the risk of hypoglycemia, or low blood sugar, and infant mortality in today's northern populations. The findings, published online October 23 in Cell Press's American Journal of Human Genetics, provide an example of how an initially beneficial genetic change could be detrimental to future generations.

"Our work describes a case where the same variant has likely been selectively advantageous in the past [but] disadvantageous under current environmental conditions," says senior author Dr. Toomas Kivisild, of the University of Cambridge, in the UK.

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When the investigators looked at the global distribution of the CPT1A variant, they found that it was present in 68% of individuals in the Northern Siberian population yet absent in other publicly available genomes. The variant has previously been linked to high infant mortality and hypoglycemia in Canadian Inuits, and its high frequency in these populations has been described as a paradox.

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