Researchers Discover New Form of Prion-Caused Fatal Insomnia

Researchers at the University of Chicago and UC San Francisco have discovered a new prion-caused disease called sporadic fatal insomnia. Prions are proteins with an unusual conformation that prevents them from being destroyed by normal cellular processes, so that they accumulate in the brain. Creutzfeldt-Jakob disease, kuru, scrapie and the so-called “mad cow disease” in Britain are all caused by prions.

In 1986, researchers discovered an inherited disease called familial fatal insomnia that has now been identified in 24 families. A genetic defect has been identified, and it is thought to be the source of the prions that cause victims, usually in their 40s, to have trouble sleeping. Sleeplessness is followed by motor difficulties, weight loss, delusions and, eventually, death. Now the researchers report in today’s New England Journal of Medicine that they have identified a sporadic case in a California man who does not have the genetic defect but does have the prion. In an editorial, researchers from Case Western Reserve University say that they have found another case. The researchers speculate that the sporadic form may be more common than the familial form, causing many cases of otherwise unexplained dementia and delusions.

Compiled by Times medical writer Thomas H. Maugh II.