Surprise finding sheds light on what causes Huntington's disease, a devastating fatal brain disorder

Scientists are unraveling the mystery of what triggers Huntington’s disease, a devastating and fatal hereditary disorder that strikes in the prime of life, causing nerve cells in parts of the brain to break down and die.

The genetic mutation linked to Huntington’s has long been known, but scientists haven’t understood how people could have the mutation from birth, but not develop any problems until later in life.

New research shows that the mutation is, surprisingly, harmless for decades. But it quietly grows into a larger mutation — until it eventually crosses a threshold, generates toxic proteins, and kills the cells it has expanded in.

“The conundrum in our field has been: Why do you have a genetic disorder that manifests later in life if the gene is present at conception?” said Dr. Mark Mehler, who directs the Institute for Brain Disorders and Neural Regeneration at the Albert Einstein College of Medicine and was not involved in the research. He called the research a “landmark” study and said “it addresses a lot of the issues that have plagued the field for a long time.”

https://apnews.com/article/huntingtons-disease-harvard-mit-genetic-involuntary-movement-b87b387b4ea37e41b43f4f9952b89117