Scientists have identified four new genes that increase predisposition to Alzheimer's disease.
More than 11,000 people with Alzheimer's were analysed by researchers from Mount Sinai School of Medicine, along with almost the same number of older people who showed no signs of dementia.
The authors of the study, published in journal Nature Genetics, hope that the findings will improve treatment for the condition by helping medical professionals to detect which individuals will develop Alzheimer's before the onset of the disease.
Researcher Joseph Buxbaum said: "Follow up studies of the genes identified, to determine how they affect brain biochemistry, are now possible in our samples, and this can help us understand how the genes contribute to Alzheimer's disease."
This comes after the Alzheimer's Society called for routine dementia screening in people over the age of 75.
While the charity believes that more than 750,000 people in the UK are living with dementia, it claims that more than half of these have not yet been diagnosed with the condition.