A team of researchers in Italy has identified a trio of gene mutations — two of them novel — believed to be linked to Alzheimer’s disease
For more than 10 years, results of genetic studies have identified mutations and variations that can either cause Alzheimer’s disease or increase the risk for developing the disease.
Specifically, familial Alzheimer disease, which affects between 5 percent and 10 percent of all cases of the disease, is believed to be influenced by mutations on genes coding for presenilin, a protein linked to plaque formation. (Alzheimer’s is often accompanied by a buildup of certain proteins or plaques in the brain.)
To arrive at their results, Sandro Sorbi, a researcher at the University of Florence, Italy, and colleagues obtained DNA from 45 individuals with familial Alzheimer’s disease. These individuals were outpatients from the neurology departments at the Universities of Florence and Parma, and the Santa Maria Nuova Hospital in Reggio Emilia, Italy.
In their research, the team identified “several families” carrying presenilin mutations, and encountered one presenilin mutation associated with “variable age of onset” Alzheimer’s disease — from 35 to 85 years old — in one family, and two “new” presenilin mutations associated with early onset disease, defined as age 49 to 54 in two other unrelated families.
The results of this study “confirm and extend the concept that the clinical manifestation of [both presenilin gene] mutations may be typical for [Alzheimer’s disease] and more similar to other dementias,” the authors wrote in their study, which appears in the November issue of The Archives of Neurology.
“In addition, the identification of new mutations is important, particularly for developing diagnostic testing programs based on the frequency of mutations in specific populations and for further enlarging our understanding of the great variability of [familial Alzheimer disease],” they wrote.
Sorbi’s team’s results may be significant — or at least may help drug makers exploit these two new mutations to develop therapeutics. According to researchers at Columbia University, “destroying” the body’s ability to create plaque “is a key strategy in developing Alzheimer’s therapeutics, because most researchers are betting that the disease stems from an excess of the beta amyloid peptides. … “
“Approaching the problem from the other side of the equation — preventing plaque from building up by stopping the production of the peptides — should also work,” the school said in a recent paper.