The genetics underlying late-onset Alzheimer's disease could soon be revealed thanks to a collaboration of leading UK experts. The team, led by scientists at Cardiff University, has received £1.3 million from the Wellcome Trust, the UK's largest medical research charity, to scan the entire human genome in search of the genes that predispose people to or protect them from developing the disease.
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. Yet currently, only £11 is spent on UK research into Alzheimer's for every person affected by the disease, compared to £289 for cancer patients.
Now, a team led by Professor Julie Williams from Cardiff University will use a technique known as genome-wide association scanning to analyze DNA samples taken from 14 000 people - 6000 with late-onset Alzheimer's disease and 8000 healthy 'control' samples from the UK and US - to identify common genetic variations that increase the risk of the disease.
"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," says Professor Williams. "With access to 14 000 DNA samples, our study is the largest genetic study ever to look at Alzheimer's and will undoubtedly produce some valuable insights into what causes this devastating illness.
"It's very likely that we will find some unexpected associations. 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 scanning is a powerful technique involving 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," says 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.