Alzheimer's Gene Tracked Down

A collaboration of scientists from the US, Canada, Europe and Asia have discovered a new gene that could be important in Alzheimer's disease... and hopefully they can remember where they put it. The researchers think that faults in a gene called SORL1 might help with the formation of clumps of protein in the brain, known as amyloid plaques. These plaques are a classic hallmark of Alzheimer's, so the researchers started to look at genes that are involved in processing amyloid proteins. To find the gene, the scientists combed through genetic data taken from many families where more than one person had Alzheimer's. They found that many of the people from the families had faults in SORL1, but not in six other genes that are thought to be involved in amyloid processing. To confirm the finding, they studied information from a wide range of families across the globe, and found the same mistakes in SORL1. The team also measured the levels of SORL1 protein in the blood of Alzheimer's sufferers. They found less than half the level of SORL1 in patients compared to unaffected people. And in lab experiments the researchers noticed that cells with low levels of SORL1 couldn't shift amyloid proteins around properly, which might suggest a way to explain the build-up of plaques in Alzheimer's patients with the faulty gene. So far, the team have found 29 different variations in the gene, in a region that's commonly faulty in the disease. At the moment they haven't mapped any of these specifically to Alzheimer's, but that will be the next stage of the project. They also want to find out if any other factors can influence the levels of SORL1, and how the different versions of SORL1 might contribute to the development of amyloid plaques.