Atlas Folding

Huntington’s Disease is a genetic disorder characterized by a loss of coordination and general motor skills (chorea) over time, accompanied by a corresponding decline in mental faculty.

Huntington’s Disease is named for the American physician Dr. George Huntington who first described the disease in a paper in 1872 at the age of 22. Having built upon research that his father and grandfather had performed, he was able to confirm that the disease was hereditary and that it was accompanied by loss of mental capacity as well. Dr. Huntington’s description of the disease in his paper On Chorea was so accurate and concise that he was afforded the honor of having the disease named after him.

Huntington’s sufferers experience unintentional, uncoordinated and sometimes wild, jerky movements as well as slurred speech. People carrying the Huntington’s gene typically begin to experience symptoms at or around age 40, however patients with severe CAG repetition can show signs at a very young age; symptomatic patients under the age of 20 are said to have Juvenile HD.

While the disease itself is not directly fatal, the loss of motor control in advanced sufferers causes an array of life-threatening complications. Surviving those, the patient will ultimately die from loss of autonomic breathing functions or heart failure.

Life expectancy of those with late onset HD is approximately 15-20 years after the appearance of symptoms. Unfortunately juvenile HD patients are by definition afflicted with very high CAG repetition rates which cause a much more rapid progression of symptoms and complications.

After decades of research it was discovered in 1983 that Huntington’s Disease is caused by a single gene, and in 1993 it was further discovered that the gene is at the 4p16.3 site on chromosome 4 and that it contains a CAG code of variable length.  This abnormal number of CAG repeats in the gene is a highly reliable way to test for Huntington’s Disease, and in fact the disease became one of the very first genetic disorders for which a test was developed.

The gene for Huntington’s Disease is “autosomal dominant”, which means that the offspring of a parent with the gene have a 50% chance of receiving it themselves as it is not sex specific.

Every individual with the gene, about 1 in 100,000 worldwide, will experience symptoms of varying degrees and age onsets.