Gene locations that increase the risk of both Parkinson’s and Alzheimer’s diseases are not widespread; therefore, the two diseases appear not to share genetic risk, report researchers from the Cardiff University School of Medicine in Wales.
The finding, published online by JAMA Neurology, is based on a combined genome-wide association analysis (GWA) of data sets from the United States, France, Germany and the United Kingdom performed by Valentina Moskvina, PhD, and colleagues. The analysis included almost 3,200 individuals with Alzheimer’s disease and about 7,300 control individuals who did not have Alzheimer’s, as well as more than 5,300 people with Parkinson’s disease and almost 12,300 control individuals without it.
The investigators found no significant evidence that the specific gene locations studied were associated with both diseases, although they pointed out that other GWA studies indicate that Alzheimer’s and Parkinson’s diseases may “represent a biological continuum.”
It’s still possible that genes for the diseases may overlap, the scientists said, but the overlap does not appear to occur in the genes primarily associated with increased risk of each disease.