Mayo Clinic researchers have discovered the inner workings of a defective DNA repair process and are first to explain why certain mutations are not corrected in cells. The finding is important because genetic instability and accumulations of mutations lead to disease. This discovery may lead to ways of fixing the process to avoid Huntington’s disease and some types of colon cancer. The Mayo team discovered that under certain conditions, a key protein fails to recognize a specific form of DNA that it needs to begin the repair process by recruiting additional proteins. They report their findings in a recent issue of Nature Structural and Molecular Biology. (http://www.nature.com/nsmb/journal/v12/n8/pdf/nsmb965.pdf). By failing to initiate repair, the defective mechanism may give rise to disabling inherited brain diseases such as Huntington’s disease, which causes select brain nerve cells to waste away. Huntington’s affects 30,000 adults in the United States, and another 150,000 Americans may be at risk of inheriting it. Friedreich’s ataxia is another neurodegenerative disease that may one day have a treatment based in part on this finding, as could a form of heritable colon cancer (hereditary non-polyposis colon cancer).
