Huntington’s – BioQuakes

In the ongoing search to understand and combat neurodegenerative diseases, scientists have recently made a significant breakthrough in unraveling the complex mechanisms behind Huntington’s Disease. This progress not only sheds light on why this devastating condition progresses slowly but also offers a promising lead in developing effective treatments to halt its fatal course.

Huntington’s disease, a hereditary disorder, is caused by a genetic mutation involving the HTT gene. This mutation results in the repetition of a specific DNA sequence, ultimately leading to the destruction of brain cells and the onset of debilitating symptoms. Until recently, it was believed that the number of repeats in the HTT gene remained constant throughout an individual’s life. However, groundbreaking research presented at the annual meeting of the American Society of Human Genetics has revealed a discovery: in certain brain cells, these repeats can multiply over time, reaching hundreds of copies. This expansion of repeats within vulnerable brain cells is now understood to be a driving force behind the progression of Huntington’s disease.

Geneticist Bob Handsaker of the Broad Institute of MIT and Harvard, who spearheaded this research, emphasized the pivotal role of these repeat expansions in triggering the cascade of events that culminate in the death of brain cells. By examining individual brain cells from both affected and unaffected individuals, Handsaker and his team uncovered a pattern of repeat expansion within a specific type of brain cell known as striatal projection neurons. These expansions, reaching up to 1,000 repeats in some cases, were uniquely concentrated in cells susceptible to Huntington’s disease.

Additionally, the research revealed an important threshold where the activity of thousands of genes within these brain cells changes significantly. This point, reached at around 150 repeats of the disease-causing gene, leads to a quick decline in gene activity, resulting in cell death within months. The exact reasons behind this sudden change are still unknown, presenting a mystery for further study.

However, amidst these uncertainties, the research offers a glimmer of hope for potential interventions. By targeting the process responsible for repeat expansion, namely the malfunction of a DNA repair protein called MSH3, scientists envision a novel approach to slow the progression of Huntington’s disease. By preventing further expansion of repeats, it may be possible to halt the relentless deterioration of brain cells, thereby halting the disease in its tracks.

As learned, Genetic mutations are changes in the DNA sequence that can lead to alterations in the proteins produced by genes. In the case of Huntington’s disease, a mutation involving the HTT gene leads to the repetition of a specific DNA sequence, ultimately causing the disease’s devastating effects on brain cells. By targeting the malfunction of a DNA repair protein called MSH3, scientists aim to address the underlying cause of repeat expansion, offering a potential avenue for intervention. This demonstrates how knowledge of genetic mutations can inform strategies for treating genetic disorders.

This research marks a significant shift in our understanding of Huntington’s disease and opens new avenues for therapeutic intervention. It highlights the importance of exploring innovative strategies that go beyond conventional approaches focused solely on reducing levels of the disease-causing protein. As we delve deeper into the intricate mechanisms underlying neurodegenerative diseases, such as Huntington’s, we inch closer to the prospect of effective treatments that could transform the lives of millions worldwide.

In the words of Dr. Leora Fox, Assistant Director of Research and Patient Engagement for the Huntington’s Disease Society of America, this research represents a pivotal moment in Huntington’s research, offering renewed hope. As we continue to unravel the complexities of Huntington’s disease, this latest breakthrough stands as a sign of progress in the ongoing quest to cure this condition. Are you confident in this breakthrough? What are your thoughts?

The process of Human Gene Editing developed with the goal to prevent future generations from suffering from genetic diseases present in past generations, like our own. Human gene editing, provided it is done only to the correct disease, alters the DNA in embryos, eggs, and sperm to the when reproduction occurs, the gene for the disease or disability is not inherited. However, two weeks ago the National Academies of Sciences and Medicine issued a report stating that human gene editing is being used to enhance people’s health or abilities. This is considered unethical according to organizers of a Global Summit on human gene editing.

Human gene editing has been given a “yellow light” because the process is not yet approved to be done on people. There are high hopes that diseases caused by only 1 genetic mutation such cystic fibrosis and Huntington’s disease will be eliminated due to this process. Unfortunately diseases that are caused by more than one genetic mutation, such as autism or schizophrenia, are not curable by this process.

National Cancer Institute

Gene Editing on humans is such a controversial topic right now: is it ethical to change genes? should the practice be used to change physical appearances? Ultimately, if Human Gene Editing is approves, who decides when it becomes too much, or unethical. This grey area is presented to be somewhere between when it is appropriate to help aid the life of a human, ridding them of a disease, and when enhancements are made.

BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: Huntington’s

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