Since scientists identified the gene responsible for Huntington’s disease in 1993, it’s now possible to do a genetic test to find out if someone carries the mutated version that causes it. Genetic testing can be used for diagnosis when symptoms appear, helping to avoid misdiagnosis, as symptoms can vary and may also result from other conditions. A doctor can order a blood test to confirm or rule out HD.
Since the mutation is inherited and present from birth, adults can also opt for testing even before any symptoms show up. Around 15-20% of people at-risk (those with a 50% chance of carrying the mutation and with a known family history of HD) choose to undergo a pre-symptomatic test. Guidelines exist to ensure the test is done in a supportive way, preparing the person for the result. Undergoing a genetic test should always be a personal choice, and proper support and follow-up are crucial. Presymptomatic testing is usually done at specialized genetic departments at hospitals, and not all hospitals offer it — sometimes a referral to an expert HD center is necessary. Even after starting the testing process, you can pause, delay, or choose not to receive your results at any time.
Testing when you have no symptoms (presymptomatic, or predictive testing) is a personal choice. Some people want clarity for life planning, and make decisions, such as having children. while others prefer not to know. The decision should always be voluntary and supported.
Access to genetic counselling, mental health support, and peer or association networks is important before, during, and after testing. Remember that access to these services and the way counselling is offered can differ by region or country. There is no single “right” time to test — only the time that feels right for you. The process can be paused or postponed at any stage, and there is no obligation to ever take or complete the test.
Before deciding to take the genetic test, it’s important to understand what Huntington’s disease (HD) is and how it is inherited. Learn about your own family history, what the HD gene mutation (CAG repeats that determine whether HD will develop) means, and how symptoms may develop over time. The test can tell you if you have the gene change, but it cannot tell you exactly when symptoms will start or how the disease will progress.
Understanding both what the test can and cannot tell you helps you make an informed decision. Talking with a healthcare provider who understands HD is really important. Take your time — there’s no need to rush. Once you get your results, it’s final, so be sure you’re ready. Also, have a supportive and trusted person by your side to talk to about your decision. Remember, you’re not alone in this.
Testing can bring clarity to planning and relieve uncertainty; it can also provoke strong emotions and alter family dynamics. Support and counselling are critical to manage both immediate reactions and long-term decisions. For some people, knowing is helpful; for others, choosing not to know feels right. People have different personalities, perspectives, and circumstances, and that is why there is no right or wrong choice.
The test determines whether you have the genetic mutation that causes Huntington’s disease. You will also get information about how many CAG repeats there are in your mutation. The number of repeats gives a hint about when you might expect disease symptoms to appear. But keep in mind that the number of CAG repeats doesn’t tell the whole story on its own, so it’s important to talk them through with a specialist (a geneticist and a psychologist), who can help explain what the results mean for you personally.
A positive test means you carry the Huntington’s disease mutation and will develop HD at some point in your life. It is not a life sentence: many people with a positive result continue to live full and meaningful lives, working, forming relationships, have and raise children (with or without the risk), and stay active. People find their own ways to cope with and live with HD.
There are different ways to have children when carrying the Huntington’s disease mutation. Children conceived naturally have a 50% chance of inheriting the mutated gene. Other options exist to reduce or avoid passing on the mutation, such as embryo testing during in vitro fertilization (IVF) before pregnancy, early prenatal testing, or using donor sperm or eggs from someone without the mutation.
Each option involves emotional, practical, and ethical considerations. Discussion with a geneticist and reproductive specialist is recommended, together with psychological support to explore which path feels most appropriate for each situation.
Results are delivered confidentially to you, usually in a face-to-face meeting with a geneticist and a psychologist. They will explain what your CAG number means and how it might affect you. It is best to have a plan in advance of who you want to inform about the result. And many people choose to bring their partner or somebody else they trust and are close to. It’s your decision, and clinicians will respect your confidentiality. However, it’s helpful to think about what information your family members might need so they can handle the situation as effectively as possible. Counsellors can help you think about whether and how to share information with family, and what practical steps to take next. Follow-up support should be offered, including emotional support, medical check-ups, planning for therapies or trials, and legal or financial guidance.
