Findings: Genetic link to Alzheimer's

Scientists at the University of Wales College of Medicine are hunting for more of the genes that contribute to Alzheimer's disease.

Julie Williams, professor of neuropsychological genetics, said that at least four genes that are implicated could soon be discovered, writes Martin Ince.

Speaking at this week's British Neuroscience Association meeting in Harrogate, she said that her team was working on a group of 80 genes on chromosome ten of the human genome. This area is shared very strongly in families with at least one Alzheimer's sufferer.

Professor Williams said: "There are already four genes that are known to be associated with Alzheimer's, but three of these relate to rare, early-onset forms. The other, Apolipoprotein E (APOE), is associated with the more usual form of the disease in people over 65, and we think we can find others like it. We know there are several more important players to be found."

She said: "Everyone has two copies of every gene. If one of the two copies of APOE you carry has the Alzheimer's mutation, you have an increased risk of the disease. If both have the mutation, the risk is vastly increased, although we are still finding out how the effect works."

Professor Williams' group is about to publish a paper on of the 80 genes. About nine of these are being followed up in more detail because of suspicions that they could be associated with susceptibility to Alzheimer's. The group is also working on suspicious zones of human chromosomes nine and 12 in the search for at least four more Alzheimer's genes.

The disease has a number of pathways and involves both environmental and genetic factors whose importance will vary between individuals.

"We expect to pin down the genetic factors in the next decade, but the environmental ones could take longer. The result could be that we will be able to structure treatments for individuals instead of having a single treatment for all Alzheimer's sufferers," Professor Williams said.

Her group has used data from the Human Genome Project to compare genes from families with Alzheimer's with a sample taken from families in which the disease is absent. She said she wanted to find families in the UK that had at least one Alzheimer's sufferer. To take part in the study, call 029 2074 3242.