A recent report in the New England Journal of Medicine on research carried out by scientists at the Medical Research Council Prion Unit, shows that a strong genetic resistance to a disease called kuru (meaning trembling with fear) has occurred in a matter of decades as a direct response to it.
Kuru is an extremely rare form of dementia found in the highlands of Papua New Guinea. It is very like new variant Creutzfeldt-Jakob disease (vCJD) , better known as mad cow disease, and BSE in cattle. Kuru, restricted to a small highland area of the island, affected a tribe called the Fore (pronounced for-ay). Kuru was the first transmissible spongiform encephalopathy (prion disease) discovered in humans.
Kuru devastated people of the Fore tribe in the mid 20th Century. It was caught during funeral rites of their dead when the body was ritually cooked and eaten. The cannibalistic ritual of primarily women and children, involved eating the brain of the dead to show respect in mourning. It was banned in the late 1950s by the New Guinea government and the practice ceased when it was found to cause kuru.
Lead author, Professor John Collinge, Director of the MRC Prion Unit and his team, studied 3000 people from the affected and surrounding area, including 709 who had taken part in the funeral rituals, 152 of whom subsequently died of kuru. They discovered a unique variation in the prion protein gene called G127V in people from the Purosa valley region where kuru was most common. The gene mutation appears to offer high or complete protection against the disease.
Kuru, like vCJD, is believed to have an incubation period of many years. Signs and symptoms of progressive neurological deterioration caused by the disease include disordered movement, tremors, unsteadiness, mood disorder, and in some, dementia. Death occurs within 6 to 12 months of the first appearance of symptoms. There is no treatment for Kuru.
Professor John Collinge says their findings have positive implications for people with kuru and its resultant dementia. “Kuru comes from the same disease family as CJD so the discovery of this powerful resistance factor opens up new areas for research taking us closer to understanding, treating and hopefully preventing a range of prion diseases”.
Source: A Novel Protective Prion Protein Variant that Colocalizes with Kuru Exposure. Published in New England Journal of Medicine11/19/2009.