Huntington’s disease is one of those conditions you might have heard mentioned in a medical drama or biology class, but few outside the medical field truly understand. While a relatively rare disease, it has a profound impact on patients and families. Here are the three main things you need to know about Huntington’s:
1. It is an autosomal dominant condition: This means only one copy of your genes, from your mother or father, must be affected for you to have the disease. That is a 50/50 chance of inheriting the disease if any one of your parents are affected.
2. It is progressive: This means that the nature of the condition will worsen, either gradually or rapidly, depending on the severity of the underlying genetic mutation.
3. It is incurable: Huntington’s disease is mainly managed supportively. Traditionally, the main aim of disease management has been to control and provide symptom relief rather than prolong life expectancy. Most will experience symptoms first in mid-adulthood (30s-40s), and average survival thereafter is 10-15 years after symptom onset.
The combination of the three – inherited, progressive, and incurable – that makes Huntington’s known as one of the most unforgiving conditions known to medicine. It tramples through tens and hundreds of generations, ending bloodlines with no hope in sight. Across Europe and the US, approximately 75,000 people have been diagnosed with the condition, with hundreds of thousands carrying the mutation that will eventually develop the disease (1).
However, the traditional picture of Huntington’s disease may be on the brink of transformation. A group of researchers at University College London has announced the results of a preliminary trial, in which an experimental gene therapy has slowed the progression of the disease by 75% over a period of three years. This was measured using the Unified Huntington’s Disease Rating Scale, which incorporates motor, cognitive, and functional aspects of the disease. In simple terms, the decline that would normally occur within one year would now take four years after the treatment (1).
Described as a major scientific breakthrough, this is essentially the first advancement seen in Huntington’s since the discovery of the gene responsible for the disease in 1993. In layman’s terms, this is a best-thing-since-sliced-bread type of development!
Not only does this give hope to families affected by Huntington’s, but it also opens doors to the potential treatment of similar inherited diseases via gene therapy. To understand the implications of this on future generations, we must first understand what gene therapy is.
- What is gene therapy?
Genes are the genetic material we inherit from our parents that contain all the instructions required for the human body to grow, function, and stay alive.
The simplest way to think of a gene sequence is to imagine a continuous chain of interlocking Lego bricks, made up of four random colours. In genes, the order or sequence of genetic material is vital. For example, let’s say you’ve connected your Legos, a green block first, followed by yellow, and then red. What happens if you swap the order of the green and yellow Lego? If we were just playing with Legos, then the worst that could happen is your little cousin getting upset and throwing a fit. For genes, a single switch in a sequence of thousands can result in debilitating conditions, such as Sickle Cell Disease.
In Huntington’s, the underlying genetic abnormality is different. It is known as a repeat expansion, where a section of a gene will repeat itself continuously, whereas in non-affected people, it is limited to a few copies. In the general population, it results in a correctly formed protein known as the Huntingtin protein, which is essential for the normal development and function of neurons. However, in individuals with a repeat expansion, the resulting protein is malformed and results in a toxic accumulation, leading to neuron death.
Here is where gene therapy comes in. With gene therapy, we can tackle the root problem instead of focusing on symptom management!
Gene therapy is a type of treatment that targets preventing or treating a disease by modifying the genetic material inside our cells. There are various types of gene editing tools, the most famous would be CRISPR-Cas9, for which Emmanuelle Charpentier and Jennifer Doudna received the 2020 Nobel Prize in Chemistry.
| Type of Gene therapy | How it works | Example |
| CRISPR-Cas9. | Directly modify gene sequence by ‘cutting and pasting’. | Sickle cell disease, beta-thalassemia. |
| Gene Silencing. | Turn off a harmful gene ; or reduce its effectiveness. | Huntington’s (AMT-130). |
| Gene modification with immunotherapy. | Genetically engineer immune cells to fight disease. | CAR-T cell therapy for cancers |
In simple terms, gene therapy attempts to manipulate the sequence of an abnormal gene in order to achieve the correct gene sequence. It can do that in various ways, each with its advantages and disadvantages.
In the experimental trial conducted by University College London, researchers used a gene silencing method. They achieved this via viral vectors, which are essentially harmless viruses that act as delivery trucks. Scientists engineer these delivery trucks to carry mRNA (think of them as mini instruction manuals) into brain cells to silence the harmful genes and subsequently result in lower numbers of the toxic protein being produced. Sounds fairly straightforward, doesn’t it? However, this whole process involved a 12-hour brain surgery. Due to the blood-brain barrier, gene therapy must be infused into the brain directly. Therefore, all 29 patients in the study underwent brain surgery to receive this treatment. However, as brain cells do not regenerate, this is a one-time treatment, meaning patients will not have to undergo additional surgeries (2).
2. How can gene therapy positively impact society?
Gene therapy can transform the world as we know it. Not only does it have the potential to cure what are thought as incurable diseases, but it also unfolds an exciting new branch of treatment known as personalized medicine. With gene therapy, the days of a ‘one size fits all’ concept can be eliminated and replaced with tailored therapies specific to a patient’s unique genetic makeup. This is specifically important in the treatment of cancers that often have various and complex genetic mutations. Additionally, these ‘one-time’ treatments can potentially replace lifelong therapies. In recent decades, medicine has seen a fundamental shift in care from symptomatic management to preventive management. As a famous Arabic proverb says, ‘prevention is better than cure’.
3. How can gene therapy negatively impact society?
Genetic breakthroughs can unfold in several directions, and transformation does not always mean improvement. Great scientific advances, such as gene therapy, require a great amount of money and time to accomplish. In 2023, an estimated $5.9Bn was spent on gene therapy research alone. Unfortunately, that makes gene therapy extremely expensive, costing an average of millions of dollars per patient. In the UK, the NHS pays £2.6m per patient for the Haemophilia B gene therapy known as Hemgenix. Unless you’re one of Elon Musk’s many children, the chances are you don’t have millions of dollars readily available to spend. Therefore, we might see an exacerbation of a prominent plight in medicine: the widening of global health gaps. Access to such life-transforming therapies will realistically be limited to wealthier nations. This can significantly deepen a well-established inequality between the rich and poor, not only in medicine, but across various aspects of life (3).
Those who oppose gene therapy will often cite one singular argument in their defence: This is not ethical. They aren’t entirely wrong. The ethical considerations that one must account for when discussing genetic therapies are so extensive that they deserve a separate article on their own. Gene therapy is a very powerful tool, one that can be used to ‘fix’ whatever problems are present in our genetic material. But then comes the main question: what classifies as a disease? What classifies as a problem? Recently, we have seen a shift in advocacy from cure to acceptance. For example, many advocates for Autism will argue against a ‘cure’, as they worry that eliminating certain conditions may devalue the people living with them
Our genetic material determines almost everything. Eye colour, skin tone, hair texture, height, etc. Yes, gene therapy can ensure parents that their children will be born free of disease, but are we guaranteed to stop there? Are we guaranteed not to go beyond, to not submit to greed and leave nothing to nature and everything to technology? Could this be the beginning of an artificial future?
In reality, the majority of gene therapy research has been theoretical in nature. Scientific trials often face many setbacks, whether financial, ethical, or technological. The possibilities are endless and will revolutionize healthcare. The Huntington’s AMT-130 trial represents one of many breakthroughs in modern medicine. It opens up new avenues and research into other inherited conditions. However, absolute power corrupts absolutely. As we stand on the brink of a new era in medicine, it is crucial that innovation moves hand-in-hand with ethics, equity, and humility.
References
1. Ucl (2025) Gene therapy appears to slow Huntington’s disease progression, UCL News. Available at: https://www.ucl.ac.uk/news/2025/sep/gene-therapy-appears-slow-huntingtons-disease-progression (Accessed: 03 October 2025).
2. Gallagher, J. (2025) Huntington’s disease successfully treated for first time, BBC News. Available at: https://www.bbc.com/news/articles/cevz13xkxpro (Accessed: 03 October 2025).
3. Gallagher, J. (2024) Haemophilia B: My £2.6m blood has ‘cured’ my haemophilia, BBC News. Available at: https://www.bbc.com/news/articles/c4nnn51rdrzo (Accessed: 03 October 2025).