Unlike many other forms of dementia, Huntington's Disease (HD) strikes relatively early in a person's life. People may develop symptoms of this genetic neurodegenerative disease as early as their 30's--sometimes even in their 20's, when it is called juvenile Huntington's Disease. It is caused by an autosomal dominant mutation in the gene called Huntingtin that causes abnormal protein development that, in turn, damages brain cells. The mutant gene becomes toxic to the brain when repeated sections of this trinucleotide repeat disorder exceed a normal range, acting to accelerate neuron decay.
With HD being a genetic disorder, it may be passed to offspring. If one parent has the gene, there is a 50% chance that children will acquire the disease because the mutated Huntingtin gene is a dominant genetic trait. If both parents have the mutated Huntingtin gene, there is a 75% probability that children will acquire the disease. The result may be that the entire brain is affected; however, the most prominent symptom is affecting the vulnerable basal ganglia, which helps control movement and behavior.
When Huntington's strikes the basal ganglia, the condition is know as Huntington's Chorea, named because of the involuntary movements that make sometimes resemble dance moves--hence the Greek chorea, or dancing. The chorea does not come on strong at the start--it builds through a series of other symptoms before becoming so pronounced that it resembles the moves one may make in dancing. It may begin as a kind of restlessness or minimal lack of coordination, later including incomplete movements or skeletomuscular tasks. Sometime around the three year point after onset, motor dysfunction becomes more recognizable and obvious. Psychomotor skills are decremented and, eventually, movements such as chewing, swallowing, speaking, and maintaining balance are affected. Eventually, failure to intervene with appropriate treatments and feeding regimens results in severe weight loss and malnutrition...sometimes becoming the cause of death.
Symptoms & Prognosis
Although manifesting physically, Huntington's Disease (HD) is not without cognitive and behavioral symptoms as well. Some of these symptoms are irritability, OCD, depression, apathy, or anxiety. As HD progresses, one may notice memory deficits, compulsion, egocentrism, and speech problems. Although symptoms to this stage may mirror those of Alzheimer's Disease or Parkinson's Disease, as the patient reches the severe stage of the disease, they are unable to walk, feed themselves, speak, and become completely dependent on a caregiver for their sustainment.
Death is not typically the result of Huntington's Disease; rather, it is the result of complications--other diseases that take advantage of the decreased effectiveness of the body to ward off infection and disease. When a person is diagnosed with Huntington's Disease, they may expect to live an average of 10-15 years after becoming symptomatic.
Treatment and Outlook
Unfortunately, current treatments may only focus on affecting the symptoms of HD, not a cure. There are, like with other treatment regimens, often side-effects that make treatment choice similar to, well, pretty much any other malady. One of the resources that is widely available are support groups, often associated with hospitals, ancillary medical facilities, and social service organizations.
Genetic testing is used to confirm a diagnosis of Huntington's Disease, but a number of people who may have relatives or otherwise suspect that they are carrying the mutated gene also have the genetic test accomplished. Having a test done without a preliminary diagnosis is, of course, a personal choice--after all, when one voluntarily undergoes genetic testing, insurance companies tend to raise your rates simply because of the implication that if you thought you were vulnerable, you likely have the disorder. One should seek out counselling prior to having the test run so that they may make a proper and informed decision, as well as having a realistic understanding of outcomes.
Lists in this article adapted from Earlstein, F. (2016). Dementia Facts & Information. NRB Publishing: Nevada.
For more resources and references on Huntington's DIsease, see the following:
Huntington's Disease News & Research: https://www.drcarlforkner.com/dementia-memory-news