From the WUSTL Newsroom…
As people age, it can be hard to predict whether they will develop Alzheimer’s disease. With the exception of a few people with strong family histories of the disease, doctors don’t know who will develop Alzheimer’s, at what age or how quickly it will progress.
Two new studies led by Washington University School of Medicine in St. Louis aim to clarify the genetic underpinnings of Alzheimer’s, a disease characterized by memory loss and cognitive decline. By studying the DNA of thousands of people, the researchers seek to identify genetic factors that raise or lower the risk of developing the disease. They also intend to find and characterize markers of the disease in the cerebrospinal fluid that surrounds the brain and spinal cord and identify new treatments.
The studies are funded by two grants totaling $7 million from the National Institute on Aging of the National Institutes of Health (NIH) and led by Carlos Cruchaga, an associate professor of psychiatry and of neurology at the School of Medicine.
“We are taking two different approaches with the same goal: to understand the genetic architecture of Alzheimer’s disease so we can figure out why some people develop the disease and others don’t,” Cruchaga said. “Both approaches are unbiased — meaning we are going in with no expectations about what genetic variants or genes we are going to find.”
One set of studies is population-based. Cruchaga and colleagues will scan the genomes of about 4,000 people, some of whom have Alzheimer’s and others who don’t. They will compare the people’s genetic variations with known molecular signs of Alzheimer’s disease. Such molecular signs, also known as biomarkers, include levels of the protein tau and the protein fragment amyloid beta in the cerebrospinal fluid. The brains of Alzheimer’s patients are characteristically spotted with tau tangles and amyloid beta plaques.
The other set of studies looks at families with more than one member diagnosed with Alzheimer’s disease. Such families likely carry genetic risk factors for the disease. Researchers will study DNA from 1,260 people from 345 families, comparing individuals who developed Alzheimer’s with their relatives who did not, to look for genes associated with an elevated risk or, especially, a reduced risk of Alzheimer’s. Few genes are known that reduce risk, but they could be crucial for understanding why some people do not develop the disease.
For the complete article, click here.