The International Genomic Alzheimer’s Project (IGAP) analyzed information from more than 94,000 individuals and found new information on the underlying causes of Alzheimer disease (AD), including five new genes that increase risk for the disease. Their findings were published in Nature Genetics.
Alzheimer’s disease progresses unstoppably and eventually cause significant reduction in brain size and capacity. Scientists believe that IL-33 protein could reverse the process. Image credit: ADEAR/NIA via Wikimedia, Public Domain
The study, which was funded in part by the National Institute on Aging (NIA) and other components of the National Institutes of Health (NIH), follows results from a 2013 study, and used more genetic data than any other study of AD to date. In addition to confirming the known association of 20 genes with risk of Alzheimer’s and identifying the new risk genes, the team identified which cellular pathways might be implicated in the disease process.
The IGAP team is led by Gerard Schellenberg, PhD, a professor of Pathology and Laboratory Medicine from the Perelman School of Medicine at the University of Pennsylvania, with lead authors, Brian Kunkle and Margaret Pericak-Vance from the University of Miami, and Benjamin Grenier-Boley and Jean-Charles Lambert from INSERM in Lille, France.
“The Alzheimer's Disease Genetics Consortium at Penn, one of the key components of IGAP, has helped organize a significant portion of the data used in this work,” Schellenberg said. “Only by pooling our data and working with international collaborators can we make these significant discoveries that we hope will pave the way for Alzheimer’s disease prevention and treatments.”
The researcher’s analysis implicated the immune system, lipid metabolism, and amyloid precursor protein (APP) metabolism. Mutations in the APP gene have been shown to be directly related to early-onset Alzheimer’s. The present study, using data from late-onset Alzheimer’s patients, suggests that gene variants affecting APP and amyloid beta protein processing are associated with both types of AD. In addition, for the first time, the study implicated a genetic link of AD to tau-binding proteins. Taken together, the findings suggest that therapies developed by studying subjects with early-onset disease could also be applied to the late-onset form of Alzheimer’s.
Source: University of Pennsylvania