Black Death immunity came at a cost to modern-day health

A genetic variant that appears to have boosted medieval Europeans’ ability to survive the Black Death centuries ago may contribute — albeit in a small way — to an inflammatory disease afflicting people today. 

Researchers used DNA collected from centuries-old remains to discern the fingerprints that bubonic plague during the Black Death left on Europeans’ immune systems. This devastating wave of disease tended to spare those who possessed a variant of a gene known as ERAP2, causing it to become more common, researchers report October 19 in Nature. That variant is…