Huntington’s Disease Case Study
Huntington’s disease is a genetic disorder of the nervous system characterized by insidious onset typically between the ages of 30-50 years and a combination of progressive trochaic hyperkinesis and mental disorders. It is also called Huntington’s chorea. Chorea remains from the Greek word “choreia”, which means “dances”. It is called in such way because of a form of hyperkinesis, which is characterized by rapid uncontrolled movements that occur in different groups of muscles (Ehret, Day, Wiegand, Wojcieszek, & Chambers, 2007). Huntington’s disease is an autosomal dominant neurodegenerative disorder of the nervous system, which is still considered incurable. The etiology of this disease is still unknown. There are no more or less reliable or understandable reasons, which would explain inferential cause of disease.
Given the history and anamnesis of Jordan and detection of the disease in his mother, there is a chance that the son could get the same gene defect (repeatability CAG) genetically. Huntington’s disease is a genetic disorder that is caused by a dominant gene; that is why in about 50% of cases it is inherited. That is with probability 1: 2 Jordan may inherit the corresponding gene from the mother. In addition, this condition affects likelihood of whether the mother was heterozygous for the corresponding gene, or it was homozygous. If the mother was homozygous dominant with two alleles, Jordan in any case inherited illness from her. If the mother was heterozygous, the probability of Jordan to inherit the disease gene is 50%. The probability of this is caused by the fact that Jordan could inherit a recessive allele or dominant. The dominant allele inheritance in Jordan respectively may develop characteristic symptoms of the disease after 30 years. However, the severity of symptoms depends on the prevailing power of the dominant component of the recessive in their contiguity. Moreover, the dominant components are able to grow with aging. Their indirect effect and sharper changes of physical and psychologcal aspects manifest with senescence.
Jordan kids have the same probability of 50% to inherit a dominant gene from the father.
Logically, the risk of disease in men and women would have to be equal.
Nevertheless, the risk of having a child with this disease statistically is much higher from ill father than from sick mother, though at the moment the cause of a more pronounced inheritance from the father is unknown (Killoran et al., 2012).
In addition, a variant of primary origin mutations in individuals without hereditary factor is available. This risk of disease manifestation is absolutely equal in men and women. The cause of this effect can be explained by idiopathic nature of disease appearance.
Dominant disorders and violation is rarely lethal due to the presence of the corresponding recessive component. That is, in terms of heterozygous inheritance of a dominant allele symptoms do not occur immediately but develop over time, allowing the individual organism to some extent physically and socially adapt to them. What is more, gradual progress in the development of the disease gives time to find adequate treatment and support an appropriate level of activity.
A special feature of Huntington’s disease is that the average age of onset of the disease is ranged between 30-50 years, but the signs of the disease may manifest in year-old children and people in old age. Since the appearance of the first symptoms, life expectancy is around 15-20 years.
Death usually occurs not due to Huntington’s disease but because of its attendant complications, including pneumonia, cardiac disease, and trauma. Also, a common cause of death is suicide. Suicide may be justified frustration of abstract thinking; people cease to be able to plan their actions, follow rules, or assess adequacy of their actions. Gradually, there may be problems with memory, depression and panic, emotional deficit, egocentrism, aggression, obsessions, problems with the recognition of others, hypersexuality, and increased harmful hhabits, such as alcoholism or gambling (Gil & Rego, 2008).
In addition to the human inability to adequately influence the performance of physical functions, a possibility of presymptomatic test is justified because of possible risk factors, such as the presence of disease in parents. From another point of view, complete genetic analysis will reveal pathology to overt symptoms, and thus allow people to prepare for possible future consequences. Results of test can shock a person because of a threat of disease appearance and its menacing symptoms. However, taking the test is reasonable aspect because in this case the conditions for social and physical adaptation are facilitated.
Diagnosis is not based only on the clinical picture but also on the results of the respective analysis. A comprehensive diagnosis of Huntington’s disease includes genetic analysis, clinical detection of the symptoms of the disease, and hereditary factor (NINDS Huntington’s Disease Information Page, 2014). This is especially true when examining patients on the early stages of the disease, as the symptoms of Huntington’s chorea usually are very reminiscent to the manifestation of schizophrenia. Correct diagnosis is very important for the appointment of adequate treatment of Huntington’s disease and proper patient management policies.
Science can already tell what is going on in the human body having Huntington’s syndrome. Firstly, gradually dying of cells occurs. Nervous system cells, including brain cells and striatum, are affected most quickly and greatly, and that causes the symptoms of the disease (Gil & Rego, 2008).
Huntington’s disease is an incurable disease since the therapy reduces primarily to the elimination of certain symptoms instead of the causes of neuronal cells death. However, prenatal diagnosis and presymptomatic tests are the first steps not only to further adequate social adaptation but also to possible prevention of disease and genetic studies aimed at treatment of a mutation at the molecular level.