United States: Scientists are only now coming to realize what kind of factors precipitate Huntington’s disease, an inherited disorder that is generally fatal and typically surfaces in middle age; it results in the loss of nerve cells in specific regions of the brain.
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It is a genetic disorder that has been connected with a specific gene alteration for many years; however, until now, it has been difficult to understand how people could have the gene alteration and not receive any signs of the disease till later in their life-span.
Detailed new research suggests that the mutation is counter-intuitively actually relatively harmless for two decades.
But it turns into a small-scale mutation, and then one day, it grows into a large one, crossing the threshold, secreting toxic proteins, and sending the cells of the organism it has invaded to their doom.
Brain changes in Huntington's disease decades before diagnosis may guide future prevention trials: https://t.co/UkBwawvEbz
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According to Dr. Mark Mehler, who directs the Institute for Brain Disorders and Neural Regeneration at the Albert Einstein College of Medicine, “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?”
Mehler called the research a “landmark” study, mentioning “it addresses a lot of the issues that have plagued the field for a long time.”
What more are the experts stating?
Brain cell death finally causes movement, thinking, and behavior disturbances. The manifestations of Huntington’s disease consist of involuntary movements, disturbances of gait, change of personality, and impaired judgment; the disease develops in the 4th decade of life, with slow progression during 10-25 years, 9news.com reported.
These are the Huntington’s that experts at the Broad Institute of MIT and Harvard, McLean Hospital, Massachusetts, and Harvard Medical received from 53 individuals who died from it and 50 people who did not have the disease, sampling half a million nerve cells.
They concentrated on Huntington’s mutation, which is a mutation in a certain gene, where in DNA, there is a three-letter sequence, CAG, and it is repeated 40 times and above.
In people who do not have the disease, this sequence is performed just 15 to 35 times.
Surprise finding sheds light on what causes Huntington's disease, a devastating fatal brain disorder https://t.co/UkA3jUcIow
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They also found that DNA segments, which include 40 or more of these “repeats,” increase in length and eventually may contain hundreds of CAGs.
More specifically, as CAGs increase in number to a level of approximately 150, certain neurons degenerate and die.
According to Steve McCarroll, a Broad member and co-senior author of the study, the findings “were really surprising, even to us,” which were published on Thursday in the journal Cell.
Repeat tracts increase gradually over the first twenty years of life, and then the rate more than doubles once the individual has about eighty CAGs, according to the researchers.
Furthermore, as neuroscience researcher Sabina Berretta mentioned, “The longer the repeats, the earlier in life the onset will happen,” 9news.com reported.