CF mutant heterozygote advantage in heavy metal exposure

Teeth and leg bones from Iron Age people are showing a 21st century scientific-research team that there might be an evolutionary silver lining to the gene defects that cause cystic fibrosis (CF)

DNA analysis of ancient archeological finds is revealing that some CF gene defects may protect those who carry them from lead and other metal poisoning, or perhaps tuberculosis. [. . .]

Since the protective CF gene mutation is so common among people living in or coming originally from central and Western Europe, Farrell suspects that the mutation first arose in that part of the world, very likely in early Celtic populations. [. . .]

To understand what in the environment could cause the mutated CF gene to occur in the first place, Farrell turned to ancient burial remains. Evidence from his earlier studies already showed that transgenic mice carrying the gene might be resistant to lead toxicity. He wanted to see if there were links to people living in Europe during the Iron and Bronze Ages.

“This was an era in which people were exposed to toxic heavy metals for the first time in history,” he says. [. . .]

The first analyses are showing that specimens containing CF gene defects were not affected by lead or other metal poisoning, hinting at the mutation’s protective advantage. The specimens also contained very little tuberculosis. The scientists can’t pinpoint exactly where the first CF carrier may have lived, but they think current day Austria is a good candidate.

Via Jean M. The manuscript is freely available at Nature Precedings: Discovery of the Principal Cystic Fibrosis Mutation (F508del) in Ancient DNA from Iron Age Europeans