Huntingtons Disease :: essays research papers

Huntingtons DiseaseHuntingtons disease, or Huntngtons chorea, is a genetic disease thatcauses selective neural cell death, which results in chorea, or irregular,jerking movements of the limbs caused by involuntary muscle contractions, anddementia. It can cause a lack of concentration and depression. It also maycause atrophy of the caudate nucleus, a part of the brain. However, symptomsvary between individuals, with some sufferers channeliseing symptoms that others donot. Those suffering from Huntingtons disease normally begin displayingsymptoms between the ages of 30 and 50, but has been known to show itself inpeople as young as two and as old as 80.Huntingtons disease is inehrited from one of the victims parents.Since the gene for HD is dominant, there is a 50% chance of a sufferersoffspring inheriting the disease. Because a victim usually does not begin todisplay symptoms until after the period in which he or she would have childrenand the disease may have been misdiagnosed in e arlier generations as Parkinsonsdisease or other similar affliction, he or she king pass along the gene withouteven knowing it.The gene for Huntingtons disease is located on the short arm ofchromosome four in cytogenetic bind 4p16.3. It was first identified in 1993.While everyone posseses this gene, in someone suffering from Huntingtonsdisease, the number of repeats of a certain trinucleotide, cytozine-adenine-guanine (CAG), is much larger than what it is in a normal person. In an averageperson, the number of repeats is between 9 and 37. But is a sufferer of HD, therepeat count is from 37 to 86. While nobody has launch a direct correlationbetween the number of repeats and the age when symptoms appear, there isevidence that people with very high numbers of repeats contract the rarer early-onset Huntingtons disease, which usually affects people under the age of 20.It is estimated that between .1 and 10 % of people who suffer from Huntingtonsdisease have obtained it through new muta tions.There are three diametric tests for Huntingtons disease. The first,presymptomatic testing, is for people who are at risk for the disease. Thesecond, prenatal testing, is a testing of a fetus at risk for the disease. Thethird type of testing, validating testing, is used on someone suspected ofhaving Huntingtons disease.Treatment of Huntingtons disease usually involves counciling andeducation about the disease of both the family and the patient. Since thesymptoms are so varied in both type and severeness from patient to patient,medical treatment must be individualized.Depression, a common symptom, is usually treated with tricyclic