Mayo Clinic researchers, along with collaborators from the National Institutes of Health (NIH) and University of Oslo, Norway, have discovered that a miscue of the body's genetic repair system may cause Huntington's disease, a fatal condition that affects 30,000 Americans annually by destroying their nervous system.
Until now, no one knew how Huntington's begins, only that it is incurable. The findings appear in the online issue of the journal Nature .
“We showed that when single-strand breaks in DNA caused by oxidative lesions were repaired, the Huntington's gene continued to add extra replacement segments,” explains Cynthia McMurray, Ph.D., a Mayo Clinic molecular biologist who led the study team. “Over time, this expansion -- especially in nerve cells -- becomes toxic.”
The finding is significant because so little is known about Huntington's. According to Dr. McMurray, the finding is the first confirmed connection between the DNA repair and progression of the disease. Leaders at the NIH, which sponsored the study, are optimistic the findings will lead to advances.
“As so often happens, basic research on a fundamental biological process -- in this case, enzymes involved in DNA repair -- leads to new insights about how diseases arise and new approaches for treating or preventing them,” said NIH Director Elias Zerhouni, M.D.