Scientists make surprise finding on what causes #Huntington’s disease - National | Globalnews.ca https://globalnews.ca/news/10964360/huntington-disease-cause-new-study/ “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.” (1/4)
“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.” (2/4)
“They focused on the Huntington’s mutation, which involves a stretch of DNA in a particular gene where a three-letter sequence – CAG – is repeated at least 40 times. In people without the disease this sequence is repeated just 15 to 35 times. They discovered that DNA tracts with 40 or more such “repeats” expand over time until they are hundreds of CAGs long. Once CAGs reach a threshold of about 150, certain types of neurons sicken and die.” (3/4)
“The research team estimated that repeat tracts grow slowly during the first two decades of life, then the rate accelerates dramatically when they reach about 80 CAGs.
“The longer the repeats, the earlier in life the onset will happen,” said neuroscience researcher Sabina Berretta, one of the study’s senior authors.” (4/4)
@auscandoc I hope this leads the way to a cure!
@auscandoc This is one of those news articles that talks about research but doesn't link to it. Here it is https://www.cell.com/cell/fulltext/S0092-8674(24)01379-5
I wanted to know if it applies to other CAG-polyglutamine repeat diseases like some of the spinocerebellar ataxias. "The dynamic we have described, in which the toxic effect of a DNA repeat is acquired only after decades of somatic expansion, could in principle also apply in other DNA-repeat disorders"
@axoaxonic Thanks for doing that. Meant to come back and do it .. but..