This site is intended for health professionals only

14,000 taking part in Alzheimer's genome scan

The genetics underlying late-onset Alzheimer's disease could be revealed thanks to a new study led by a Cardiff scientist who has been awarded a £1.3m grant from the Wellcome Trust for the research.

Professor Julie Williams of the School of Medicine will lead a team of UK experts studying DNA samples taken from 14,000 people worldwide in search of the genes that not only predispose people to Alzheimer's, but which can protect them from developing the disease too.

The researchers will use a powerful screening technique called "genome-wide association" scanning to analyse the DNA samples, the first 1,000 of which will come from participants in Wales.

Professor Williams said: "Alzheimer's is a genetically complicated story involving many genes, so we need large sample sizes to make sure any genetic links that we find are not mere coincidence.

“With access to 14,000 DNA samples, this is the largest genetic study ever to look at Alzheimer's and will undoubtedly produce some valuable insights into what causes this devastating illness.”

According to the Alzheimer's Research Trust, there are over 700,000 people currently living in the UK with dementia, of which Alzheimer's is the most common form. This figure is expected to double within the next 20 years.

The new study will take DNA samples from 6,000 people with late-onset Alzheimer's disease and 8,000 healthy "control" samples from Britain and America to identify common genetic variations that increase the risk of the disease.

"It's very likely that we will find some unexpected associations” said Professor Williams. “We know already that certain genes are involved in more than one form of dementia and that even genes that affect cholesterol level can be a risk factor for Alzheimer's. We need to build a complete picture of the different pathways that lead to the disease. With this knowledge, we should, in time, be able to derive tangible clinical benefits."

"Genome-wide association" involves studying 500,000 genetic markers across the human genome. Work on genotyping the DNA samples - in other words, screening for the particular genetic mutations that are linked to Alzheimer's disease - will be performed by Dr Panos Deloukas's group at the Wellcome Trust Sanger Institute.

"Alzheimer's disease is a major burden on our society and this burden will only increase as our population ages," said Professor Richard Morris, Head of Neurosciences and Mental Health at the Wellcome Trust, which is funding the study. "It is essential that we develop our understanding of the underlying causes of the disease, and genome-wide association scans offer a powerful tool to do just this."

The project has been welcomed by Rebecca Wood, Chief Executive of the Alzheimer's Research Trust who said: "This is an exciting project that could lead to real progress in our understanding of Alzheimer's."

Cardiff University