Gene scientists have taken a “leap forward” in Alzheimer's research with the potential to cut rates of the disease by a fifth, it has been revealed.
Two international British and French-led teams together identified three new genes closely linked to the illness.
Cancelling out their effects could prevent almost 100,000 cases of “common” late-onset Alzheimer's a year in the UK.
Clues from the genes are already challenging previous assumptions about how the disease develops and pointing the way towards possible new therapies.
Professor Julie Williams, who led the British team, described the breakthrough as “the biggest advance in Alzheimer's research in 15 years”.
Alzheimer's is the most common form of dementia, affecting more than half the 700,000 people in the UK suffering from the condition.
In less than 20 years, almost a million people in the UK are expected to be living with dementia. This figure is forecast to soar to 1.7 million by 2051.
The three genes are the first to be associated with the common form of Alzheimer's since 1993, when a mutant form of a gene called APOE was found to account for about a quarter of cases.
Two, known as clusterin, or CLU, and PICALM, were identified by the UK team. The third, complement receptor 1, or CR1, was identified by the French-led group.
Having certain versions of these genes increases the risk of Alzheimer's by 10% to 15%.
The British-led study was the largest genetic investigation of Alzheimer's ever conducted and involved analysing the DNA from more than 16,000 individuals over two years.
Professor Williams, from the Medical Research Council Centre for Neuropsychiatric Genetics and Genomics at the University of Cardiff, said:”If we were able to remove the detrimental effects of these genes through treatments, we could reduce the proportion of people developing Alzheimer's by 20%. In the UK alone this would prevent just under 100,000 people developing the disease.”