Kuru: Gene variants may protect against brain disease linked to cannibalism

A genetic study in an extremely remote community in Papua New Guinea has uncovered new insights into a brain disease that people spread by eating their dead relatives, which killed thousands of people in the 20th century.^th century.

Papua New Guinea’s Eastern Highlands province, a collection of mountains, canyons and fast-flowing rivers, was isolated from the rest of the world until the early 1920s.^th Century outsiders realize it is home to about a million people.

Some tribes known as the Fore practiced a practice of cannibalism known as “peaceful feasting,” in which the bodies of deceased relatives were eaten as part of funeral rituals.

This sometimes means they consume abnormally folded proteins (called prions) that cause a fatal neurodegenerative disease called kuru, which is related to Creutzfeldt-Jakob disease (CJD). However, locals believe that kuru is caused by witchcraft. At least 2,700 kuru deaths have been recorded in the Eastern Highlands.

Simon Mead The professor from University College London and colleagues examined the genomes of 943 people from the region, representing 68 villages and 21 language groups. Researchers say that although this region of Papua New Guinea covers just over 11,000 square kilometers and is smaller than Jamaica, the different groups are genetically distinct, like the Finns and Spanish, who are about 3,000 kilometers apart.

Research has found that not everyone who attends a mortuary feast succumbs to the disease. Meade and his colleagues say communities appear to have begun to develop some resistance to kuru, which can cause tremors, loss of coordination and ultimately death.

Research has found that some older women who survived the feast carried a mutation in the gene encoding the prion protein that may have made them resistant to kuru.

By the 1950s, as mortuary feasts became illegal, the kuru epidemic began to recede, but visitors noticed that in some villages the number of women had dwindled because too many people were dying of kuru. Meade said women and children may be most vulnerable to the disease because they eat the brains of their dead relatives.

However, genetic evidence suggests that despite fears about the disease, there was an influx of women into the Fore tribal areas, particularly areas with the highest incidence of kuru.

“It seems to us that the gender bias caused by kuru may cause bachelors in kuru-affected communities to search for wives from further away than usual because of a lack of potential wives locally,” Mead said.

He said the team wanted to understand what factors protect against prion diseases such as Creutzfeldt-Jakob disease, which caused a serious epidemic in the UK in the 1990s.

“(Our work) lays the foundation for testing genetic factors that may help the Fore resist kuru,” Mead said. “Such resistance genes may suggest therapeutic targets.”

Ella Deveson The study provides new insights into the “rich and unique cultural, linguistic and genomic diversity” of the Eastern Highlands, said the professor at the Garvan Institute of Medical Research in Sydney, Australia.

“This demonstrates that genomics can be used almost to look into the past – to read the genetic signatures of past epidemics and understand how they shaped today’s populations.”