NEW YORK, June 23, 1999 -- A single alteration in the DNA alphabet occurring in a newly discovered human gene causes an unusual form of hereditary dementia characterized by amyloid deposits in the brain, one of the hallmarks of Alzheimer's disease, according to a new study by New York University School of Medicine scientists. The discovery solves a longstanding medical mystery involving descendants of a British woman who died in 1883 and may help lead to a better understanding of Alzheimer's and other dementias.

The NYU School of Medicine researchers found the genetic alteration, or mutation, in a gene they dubbed "BRI." The unusual mutation, which occurs at a "stop codon," produces an abnormal protein fragment that forms plaques in the brain of affected family members, according to the new study in June 24 issue of Nature. The researchers developed a blood test to detect the mutation.

"Our hope is that this genetic mutation, which causes a disease as devastating as Alzheimer's, will lead to a better understanding of how neurons are actually lost in the brain," says Jorge Ghiso, Ph.D., Associate Professor of Pathology at NYU School of Medicine, an author of the new study. "This is an important finding because it will give us another window onto the brain diseases associated with amyloid."

According to Creighton H. Phelps, Ph.D., Director of the Alzheimer's Disease Centers Program at the National Institute on Aging, "This exciting discovery provides new opportunities to uncover the cascade of events leading to the loss of synapses and neurons triggering the development of dementia. If we can interfere with this cascade, common to many of the dementias, including Alzheimer's, we may be able to stall the disease process in its tracks."

Amyloid is a general term used to describe proteins that form so-called beta-sheets, which fold in a particular way to form deposits in the brain. A number of brain disorders associated with dementia are linked
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Contact: Deborah Miller
Deborah.Miller@med.nyu.edu
212-263-5800
New York University Medical Center and School of Medicine
23-Jun-1999