Brain disease "resistance gene" could offer insights into CJD

A community in Papua New Guinea that suffered a major epidemic of a CJD-like fatal brain disease called kuru has developed strong genetic resistance to the disease, according to new research by Medical Research Council (MRC) scientists, from the MRC Prion Unit in the UCL Institute of Neurology.

Kuru is a fatal prion disease, similar to CJD in humans and BSE in animals, and is geographically unique to an area in Papua New Guinea. The infection was passed on at mortuary feasts, where mainly women and children consumed their deceased relatives as a mark of respect and mourning. This practice was banned and ceased in the late 1950s. Medical Research Council experts assessed more than 3,000 survivors of the mid-20th Century epidemic and found a gene variation, G127V, in people from the Purosa valley region of the Eastern Highlands.

This gene mutation, which is found nowhere else in the world, seems to offer high or even complete protection against the development of kuru and has become frequent in this area through natural selection over recent history, in direct response to the epidemic. This is thought be perhaps the strongest example yet of recent natural selection in humans.

Professor John Collinge, Director of the MRC Prion Unit & Head of the Department of Neurodegenerative Disease said: “It’s absolutely fascinating to see Darwinian principles at work here. This community of people has developed their own biologically unique response to a truly terrible epidemic. The fact that this genetic evolution has happened in a matter of decades is remarkable. 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.”

Dr Simon Mead who led the research said: "This work is a classical example of recent and strong human evolution, and sheds light on the mechanisms of the protein misfolding diseases"

The study which began in 1996, was published in the New England Journal of Medicine on 19 November 2009.

More >> MRC Press release | BBC News | Telegraph

Reference >> A Novel Protective Prion Protein Variant that Colocalizes with Kuru Exposure. Simon Mead, Jerome Whitfield, Mark Poulter, Paresh Shah, James Uphill, Tracy Campbell, Huda Al-Dujaily, Holger Hummerich, Jon Beck, Charles A. Mein, Claudio Verzilli, John Whittaker, Michael P. Alpers, and John Collinge. New England Journal of Medicine  Volume 361:2056-2065. November 19, 2009                              

Text derived from material supplied by the MRC.