Pooling of data reveals five new genes that boost Alzheimer’s risk
An international consortium analyzed genetic data from more than 94,000 individuals and in the process discovered five new genes that increase risk for Alzheimer’s disease.
The International Genomic Alzheimer’s Project (IGAP), composed of four consortia in the United States and Europe that have been collaborating since 2011 on genome-wide association studies (GWAS), conducted an analysis of both rare and common gene variants in patients with late onset Alzheimer’s disease.
“Having more and more samples in GWAS datasets is like adding more and more pixels to a photograph—it helps researchers see details that they otherwise wouldn’t and helps them decide where to focus further study,” said Marilyn Miller, director of the Genetics of Alzheimer’s Disease program in the Division of Neuroscience at the National Institute on Aging. “If the genes only appear in one out of 10,000 people, you need to find several samples containing those genes for results to be statistically significant.”
In fact, the study, funded in part by the National Institutes of Health and published last week in the journal Nature Genetics, was the largest-ever Alzheimer’s gene study.
“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,” says co-author Gerard Schellenberg, a professor of pathology and laboratory medicine at the University of Pennsylvania’s Perelman School of Medicine.
He noted that the Alzheimer’s Disease Genetics Consortium at Penn—part of IGAP—helped organize a significant portion of the data.
In addition to identifying the five new risk genes, the study confirmed the known association of 20 genes with risk of Alzheimer’s disease.
“An international team of researchers also reports for the first time that mutations in genes specific to tau, a hallmark protein of Alzheimer’s disease, may play an earlier role in the development of the disease than originally thought,” according to NIH. “These new findings support developing evidence that groups of genes associated with specific biological processes, such as cell trafficking, lipid transport, inflammation and the immune response, are ‘genetic hubs’ that are an important part of the disease process.”