An international research team led by scientists at the University of Edinburgh and the University of Queensland has identified three new genes linked to the risk of Alzheimer's disease

The study, supported by Alzheimer's Research UK and also involving researchers from the Icahn School of Medicine at Mount Sinai, is published today (18 May) in the journal Translational Psychiatry.

The researchers combined findings from an existing study of Alzheimer's genetics, with those from a new analysis involving the children of people with the disease. The findings are set to help researchers better understand the mechanisms underlying Alzheimer's and could open the door to new approaches for treating the disease.

To find genetic risk factors for diseases like Alzheimer's, researchers generally compare the DNA code of people with and without the disease. By carefully analyzing data from very large groups of people, researchers can pick out gene variations that are more common in people who have Alzheimer's. This approach has helped to find around 30 genes that are associated with Alzheimer's risk.

In this new study, Alzheimer's researchers used a technique that allowed them to cast their nets more widely and include many more people in their genetic analysis. The research involved genetic information from over 300,000 people from the UK Biobank.

As most of the participants were too young to be diagnosed with Alzheimer's, the research team looked to medical information about their parents, many of whom had developed the disease.

On average, children share 50% of their genes with each of their parents. While at the individual level having a parent with Alzheimer's doesn't mean you are at a much greater risk of the disease, by combining data from many thousands of people whose parents developed Alzheimer's the researchers were able to sift out genetic information relevant to the disease.

The team combined results from their new analysis with data from an existing genetic study involving 70,000 people with and without Alzheimer's disease. The findings highlight three new genes that may play a role in Alzheimer's risk.

"By focusing on people with a family history of Alzheimer's, we have been able to take advantage of a wealth of existing data to gain new insights into the genetics of the disease. One challenge of this method is that we rely on people to provide accurate information about whether their parents developed Alzheimer's, and in some cases, the disease can be mistaken for another form of dementia or go undiagnosed."

Prof Peter Visscher

"Dr. Marioni is unlocking the power of big data by applying cutting-edge statistical techniques to rich medical, genetic and lifestyle information provided by hundreds of thousands of research volunteers.

"There are currently no treatments to slow or stop the progression of Alzheimer's, but research can change this picture. Alzheimer's Research UK is proud to be supporting this pioneering research, none of which would be possible without the efforts of our dedicated supporters."