Huntington’s disease (formerly known as Huntington’s chorea) is an inherited disorder that causes mood changes, loss of mental abilities, and involuntary movements. Approximately 30,000 people in the U.S. have Huntington’s. Although it was previously considered a rare disorder, it is now recognized as one of the more common inherited diseases.
Symptoms
Huntington’s usually appear in middle age, although age of onset varies greatly. In general, the later the age of onset, the more slowly the disease progresses. Early symptoms include mood swings, trouble learning new information, or difficulty making a decision. As the disease progresses, symptoms include problems with coordination, uncontrollable movements (chorea), muscle spasms, and worsening memory loss. In the last stages of the disease, patients have progressive difficulty speaking, swallowing, and walking. A person with Huntington’s eventually dies from disease complications, such as heart failure or pneumonia. Duration of the disease, from diagnosis to death, is about 10-25 years.
Cause
Huntington’s disease is caused by a genetic defect on chromosome 4. This defect causes problems in a protein called huntingtin. The abnormal huntingtin protein tends to clump together in nerve cells. These clumps of protein damage and then destroy nerve cells in various parts of the brain, including the basal ganglia and cortex. A child of someone with Huntington’s disease is considered “at risk” for the disease, because he or she has a 50-50 chance of inheriting the faulty gene and developing the disease. A gene test is available to test for Huntington’s.
Treatments
Medications and rehabilitation therapies can help lessen many of the symptoms of Huntington’s. Counseling services can help families cope with the consequences of having a loved one with a progressive illness. A genetic counselor can help an “at risk” person make a decision about whether to have the gene test for Huntington’s.
For More Information
National Institutes of Health (NIH)
HD Society of America
Huntington’s Study Group
HD and Caregivers