Huntington’s Disease

Huntington’s disease is a genetic disorder that causes nerve cells to gradually break down and die. This disease is very rare, affecting about five in every 100,000 people in the United States. A mutation in the HTT gene causes it to fold incorrectly and clump together. These clumps over time begin to damage the brain cells. Huntington’s disease follows a dominant inheritance pattern which means that only one mutated copy of the HTT gene is needed to express the effected phenotype / have the disease.

Symptoms of Huntington’s disease usually start between ages 30 – 50 years old for adult onset. However, if there is a known family history of the disease, the phenotype can be expressed at an earlier age which is why it is important to get genetic testing done. Common symptoms of Huntington’s disease include a variety of motor, cognitive, and emotional symptoms. One of the first signs of the disease is chorea, which is a twisting movement that a person cannot control. Chorea usually begins in the extremities (fingers and toes) and spreads to other parts of the body. Other motor symptoms could include muscle stiffness, balance problems, and speech problems. Cognitive symptoms could range from impaired judgement and slowed reaction time to difficulty learning. Finally, emotional symptoms of Huntington’s disease are anxiety, depression, anger, and personality changes. These symptoms are due to the degeneration of the neurons in the brain due to the mutated HTT gene. The gene can no longer provide instructions to make the huntingtin protein which is necessary for normal neuron function.

The most common treatment for the symptoms of Huntington’s disease is medication. VMAT2 inhibitors can be prescribed to reduce the involuntary movements that someone with this disease may experience. Some medications that treat diseases like Parkinson’s can also help people who suffer from Huntington’s disease. An example of these medications includes dopamine agonists and levodopa. To relax muscles, a Botulinum toxin injection can be useful as well. For emotional symptoms, antidepressants and mood stabilizers can be beneficial in reducing symptoms.

References

Huntington’s disease. Massachusetts General Hospital. (n.d.). https://www.massgeneral.org/neurology/treatments-and-services/huntingtons-disease

U.S. Department of Health and Human Services. (n.d.). Huntington’s disease. National Institute of Neurological Disorders and Stroke. https://www.ninds.nih.gov/health-information/disorders/huntingtons-disease

What is Huntington’s disease? Cleveland Clinic. (2025, December 30). https://my.clevelandclinic.org/health/diseases/14369-huntingtons-disease