Huntington's Disease: Family Fight
... of getting HD. In order to find the origin of a genetic disorder, one must first find the gene that causes it. In 1993, after a ten-year search, scientists announced the discovery of the gene which causes Huntington's disease. This breakthrough has led to the development of a direct gene test for HD which can be used to predict the onset of Huntington's before symptoms develop. This test is more accurate and less complicated than the genetic marker test which has been in place since 1986. The gene discovery shows the Huntington's disease is caused by a genetic stutter---a stretch of DNA repeated over and over at one end of a gene on Chromosome four. Efforts continue to determine precisely how this genetic mutation leads to the symptoms of the disease. There exists an instability or error when the chromosomes reproduce, probably in sperm production (e.g. only in paternal descent is there anticipation or an increase in the number of CAG repeats). This probably started as a random mutation with a 'founder' effect. (That means that someone back probably in the 1600's had the original mutation.) The more often this pattern, or “genetic stutter” is repeated, the earlier symptoms will show. Symptoms of Huntington’s disease are different for each individual. However, the most common symptoms are chorea, poor short-term memory and judgment, depression, irritability, and apathy. Chorea, the most obvious of the symptoms, is quick, uncontrollable, jerky movements of the limbs and face. These movements cause patients to have trouble with activities that involve motor skills such as walking. Most patients are able to recall people and things, unlike Alzheimer patients, however as the disease progresses, they will suffer declining mental skills. Depression, irritability and apathy can be noted before and after the onset of chorea in a percentage of the Huntington's disease population. Some patients may exhibit schizophrenic-like behavior. Also, the inability to do sequential tasks (Sort clothes to coloreds and whites, wash coloreds in cold water, put in dryer, then wash whites in hot water, put in dryer while folding coloreds), to clumsiness making it difficult to perform simple tasks to the chorea interfering with your ability to do things are also major symptoms. If there is a positive family history of Huntington's disease, the presence of an extrapyramidal movement disorder (when nerve impulses are not properly transferred to the muscles) is usually enough to confirm a diagnosis. Conventional neurological examinations and the presence of depression and other psychological disturbances are not enough to provide an accurate diagnosis. The disease affects each person differently and symptoms can advance faster or slower depending on the person. Most of those who suffer from the disease will begin to see these symptoms between the ages of 30 and 50. However, the age of onset can range from 2 to 80. There have been some cases where children under the age of ten have shown symptoms of Huntington’s disease. However, this is very rare. HD can run its course in 10 to 25 years. Many patients do not die from the disease. Instead, they die from complications such as heart failure or pneumonia. Huntington’s disease is referred to as a family disease. This is because it does not only affect one person. The other obvious people that it affects are those directly related to the patient. Children of HD patients have a 50% chance of inheriting it from his or her parent. Unfortunately, some people give up before the struggle even begins. They treat the fifty-fifty risk factor as if it meant 100 percent certainty that they will get the disease. Many of these people think that once diagnosed they will turn into “vegetables.” This can lead to depression in people who may not even have the gene. Also, the suicide rate among HD patients is seven times the American average. I believe that these misconceptions are largely due to a lack of education on the disease. It can take de...