Over half of our genomes are made of repeating elements within DNA. In rare cases, these repeats can become unstable and grow in size. These repeat “expansions” cause neurodegenerative diseases such as ALS and Dementia as well as learning disorders and autism in Fragile X syndrome. Research to date has focused on how these expanded repeats cause disease, but little attention has been given to the repeats themselves and whether they might have normal functions in genes.
By focusing on the biology of healthy nerve cells, a team from the University of Michigan Department of Neurology found that repeats in the gene that causes Fragile X Syndrome normally regulate how and when proteins are made in neurons. This process may be important for learning and memory in these nerve cells and potentially in people. “The repeats function like a switch, slowing down protein production and then quickly turning things back on,” explains Peter Todd, MD., Ph.D., and Principal Investigator of this research.