Huntington’s disease is an inherited neurodegenerative disease caused by a genetic defect on chromosome 4. The Huntington’s disease gene is dominant, so that a single copy of the abnormal gene, inherited from one parent, is sufficient to cause the disease. Therefore, the children of a Huntington’s disease patient have a 50% chance of developing Huntington’s disease.
Huntington’s disease is caused by the gradual degeneration of parts of the basal ganglia, primarily affecting the cells of the caudate nucleus and putamen, which are directly related to movement.
Behavioral changes are usually the first symptoms, and include antisocial behavior, irritability, moodiness, restlessness or impatience among others.
Motor disorders such as facial grimacing, rapid and sudden jerky movements of the arms, legs, face and other body parts, slow and uncontrollable movements or unsteady gait are also present.
The main cognitive deficits are related to memory and learning ability, reasoning and problem solving, organization, planning, sequencing and flexibility.
There is currently no cure. There are medications that can help control some symptoms, such as chorea or depression and anxiety, but they cannot slow or stop the disease.
References: MSD Manuals (2020). Huntington’s disease. MSD manual version for professionals.