A genetic link between mother and child leading to a dysfunction in how the brain processes sugar may predispose a metabolic impairment that is a precursor to Alzheimer's disease, researchers say.

"Overall, these findings show that their brains are not working properly to start with, and the metabolic impairment gets worse over time," explained lead researcher Lisa Mosconi, a research assistant professor of psychiatry at the Center for Brain Health at NYU Langone Medical Center in New York City.

There is evidence that having a parent affected with Alzheimer's disease increases the risk of developing Alzheimer's disease four-to tenfold, Mosconi said.

"However, we don't know why or how this happens. Our study shows for the first time that individuals with an Alzheimer's disease affected mother may be at increased risk for developing Alzheimer's disease themselves because their brains are not utilizing glucose in an effective way," she said.

Mosconi's team used PET scans to look at glucose metabolism in the brains of 66 healthy individuals for the study. Some of the participants had a family history of Alzheimer's disease, and some did not.

The researchers discovered that people whose mother had Alzheimer's had a much faster progressive reduction in the use of glucose in areas of the brain affected by the disease, compared with people who had a father with Alzheimer's or parents without the disease.

"At this point, we can only speculate that genes that are maternally inherited may alter brain metabolism," Mosconi said. "We need to follow subjects for longer time periods to ascertain whether the metabolic reductions are in fact forerunning cognitive deterioration."

(Agencies via Xinhua August 1, 2008)