Genes That Affect Brain's Immune Cells May Increase Risk of Alzheimer's

A study in Science Translational Medicine found genes that affect the brain's immune cells may contribute to the risk of developing early-onset or late-onset Alzheimer's, reports Being Patient . The researchers identified two genes, MS4A4A and TREM2, in the microglia, which influence the levels of a protein also called TREM2. Scientists think this protein regulates the microglia's ability to purge amyloid and tau from the brain, and the alteration of its levels by the two genes exacerbates the danger of developing Alzheimer's. An examination of 813 older adults found some had Alzheimer's, while some had mild cognitive impairment, and some were considered cognitively normal. "We observed TREM2 risk variants more often in people who had Alzheimer's or were mildly cognitively impaired, compared with those who were cognitively normal," said Washington University School of Medicine Professor Celeste Karch. She noted about 30 percent of the study population exhibited some level of variation with the MS4A4A gene, which could either raise their risk of Alzheimer's or shield them from it. NeuroGenomics and Informatics Group Professor Carlos Cruchaga said the findings suggest "if we can do something to raise levels of the TREM2 protein in the cerebrospinal fluid, we may be able to protect against Alzheimer's disease or slow its development."