Surprising Discovery Reveals Causes Behind Huntington’s Disease Progression

Boston: Scientists are making strides in understanding Huntington’s disease, a serious genetic disorder that affects the brain. This condition usually hits people in their prime, leading to the death of nerve cells and causing major issues with movement and thinking.

For a long time, researchers knew about the genetic mutation linked to Huntington’s, but they were puzzled why symptoms didn’t show up until later in life. New findings reveal that the mutation can sit quietly for decades before it becomes harmful. It grows into a larger mutation that eventually produces toxic proteins, leading to cell death.

Dr. Mark Mehler, who leads a brain disorders institute, called this research a “landmark” study. It tackles a big question in the field: why does a genetic disorder show up later in life? The symptoms of Huntington’s, like involuntary movements and personality changes, usually start between ages 30 and 50 and can worsen over 10 to 25 years.

The research team, including scientists from the Broad Institute and Harvard, analyzed brain tissue from 53 Huntington’s patients and 50 healthy individuals. They focused on a specific DNA sequence that repeats itself. In people with the disease, this sequence is repeated at least 40 times, while in healthy individuals, it’s only 15 to 35 times. They found that these repeats can expand significantly over time, and once they hit around 150 repeats, certain brain cells start to die.

Steve McCarroll, a co-author of the study, said the results were surprising. The study, published in the journal Cell, was partly funded by the Howard Hughes Medical Institute. The researchers noted that the repeat sequences grow slowly in the first two decades of life but speed up dramatically once they reach about 80 repeats.

The longer the repeats, the earlier the symptoms appear. Some scientists were skeptical at first, but McCarroll clarified that while fewer than 100 repeats aren’t enough to cause the disease, having at least 150 is.

This research could lead to new ways to delay or prevent Huntington’s, which currently affects about 41,000 Americans. While some experimental drugs have struggled in trials, the new findings suggest that targeting the expansion of DNA repeats might be a more effective approach.

Though there are no guarantees, McCarroll mentioned that many companies are now looking into this strategy. It’s an exciting time for research in this area, and there’s hope for better treatments in the future.