A groundbreaking study published in Cell on January 16 has shed light on the long-standing question of why Huntington’s disease symptoms typically appear in midlife, despite patients being born with the genetic mutation. Researchers have discovered that the DNA sequence driving the disease expands slowly over decades in specific brain cells before rapidly lengthening and killing the cell.
Contrary to previous assumptions, the inherited mutation doesn’t immediately harm cells. Instead, the stretch of DNA remains stable for years, gradually increasing in number until it reaches a toxic threshold. This tipping point triggers cell death, leading to the characteristic neurodegenerative symptoms associated with Huntington’s disease.
The study, conducted in donated human brain tissue and led by scientists at Harvard Medical School, the Broad Institute of MIT, and McLean Hospital, offers a new understanding of the disease and its relationship to other disorders caused by abnormal DNA repeats. This breakthrough has significant implications for developing new treatment strategies for Huntington’s and other related conditions.
The researchers’ findings also provide insight into why some brain cells are more susceptible to the mutation than others, and how this affects disease progression. By unlocking these mysteries, scientists hope to develop innovative therapies that target the root causes of these devastating diseases.
Source: https://hms.harvard.edu/news/new-understanding-how-genetic-mutation-causes-huntingtons-disease