Huntington’s disease (HD) has long been impossible to cure, but new research is finally giving fresh hope. HD is a progressive, hereditary brain disease that affects movement, cognition and emotions. Doctors often diagnose HD when people show clear movement problems, typically around 30-50 years of age, after which patients live about 15-20 years.

The global prevalence of HD is about five per 100,000 people. While it is not as prevalent as Alzheimer’s disease, the disease starts much earlier in life, often when people are still in work and raising families.

Sadly, there is no cure. But a couple new research papers, by our team and others, suggests this may be about to change.

The causes of HD long remained a mystery since it was discovered in the 19th century. But in 1993, researchers uncovered that HD is caused by repetitive expansions of three DNA letters (C, A and G) in the Huntingtin (HTT) gene, resulting in the production of a mutant huntingtin protein.

This gene normally has a section that repeats the letters CAG over and over. In healthy people, the repeat is lower than 35. Repeat lengths greater than 39 will result in HD. The more repeats you have, the earlier symptoms usually start. In addition to your inherited CAG length, this sequence tends to continually expand in certain cells over a person’s lifetime, known as somatic expansion.

At the time, in 1993, the discovery generated lots of excitement. First, you could identify which relatives in a family with a history of the disease would develop it. Those of us working in HD clinics at the time were highly concerned about the ethical and mental........

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