Alzheimer's risk gene damages brain 50 years before disease starts


Washington, May 14 (ANI): A new study has revealed that carriers of a common Alzheimer's risk gene have impaired brain wiring, 50 years before the disease typically strikes. Paul Thompson, a UCLA professor of neurology, and his colleagues report that the C-allele of the CLU gene (an allele is one of two or more forms of a gene), which is possessed by 88 percent of Caucasians, impairs the development of myelin, the protective covering around the neuron's axons in the brain, making it weaker and more vulnerable to the onset of Alzheimer's much later in life. The researchers scanned the brains of 398 healthy adults ranging in age from 20 to 30 using a high-magnetic-field diffusion scan (called a 4-Tesla DTI), a newer type of MRI that maps the brain's connections. They compared those carrying a C-allele variant of the CLU gene with those who had a different variant, the CLU T-allele. They found that the CLU-C carriers had what brain-imaging researchers call lower "fractional anisotropy" - a widely accepted measure of white-matter integrity - in multiple brain regions, including several known to degenerate in Alzheimer's. Thompson said four things are surprising with the discovery of this gene's function: This risk gene damages your brain a full 50 years before people normally get Alzheimer's. The damage can be seen on an MRI scan, but there are no symptoms yet. It's now known what this mysterious gene does - namely, make your brain wiring vulnerable to attack by impairing the wiring before any senile plaques or tangles develop. The study has been reported in the online edition of the Journal of Neuroscience. (ANI)