Note: Single-source report; awaiting corroboration.
Huntington’s disease arises from a mutation in the gene that produces the huntingtin protein. This mutation creates a defective protein with toxic effects in brain cells, particularly in regions controlling voluntary movement, leading to cell death.
Individuals with Huntington’s often experience uncontrollable, irregular movements known as chorea, body stiffness, and movement difficulties. Symptoms worsen over time and may include problems with swallowing, cognition, emotions, posture, and speech. Eventually, patients may lose the ability to walk or care for themselves, and some may experience hallucinations or delusions.
The genetic mutation involves repeated DNA sequences in the huntingtin gene. Most people have fewer than 27 repeats, but those with 36 or more typically develop Huntington’s. Individuals with 27 to 35 repeats usually do not develop the disease but can increase risk for their children. A higher number of repeats generally leads to an earlier onset of symptoms.
Genetic testing can determine the number of repeats but is not sufficient for diagnosis, which requires clinical evaluation and observation of specific movement symptoms.
Current treatments do not prevent or slow Huntington’s disease. Researchers, including Dr. X. William Yang and colleagues, are investigating ways to modify the gene and reduce defective huntingtin protein levels. Studies also examine the roles of other genes using animal models where huntingtin gene repeats increase over time, closely mirroring human cases.