Prions changed one population's genes

Kuru, a fatal prion disease, spread through mortuary feasts in the Papua New Guinea highlands. Cases fell once the practice stopped. A 2009 study of more than 3,000 people, co-led by Australian researcher Michael Alpers, found that survivors who had been exposed were mostly heterozygous at PRNP codon 129. It also found a new variant, G127V, only in the kuru region and never in people with kuru. It seems to protect against prion disease.