Biology - Prader-Willi Syndrome Research Paper Example | Topics and Well Written Essays - 1000 words

Biology - Prader-Willi Syndrome - Research Paper Example It was first described by Andrea Prader and Heinrich Willi in 1956. It is a rare genetic disorder in which seven genes or some subsets are deleted, translocated or unexpressed on the paternal chromosome 15. For the genes affected in PWS, the paternal copy is expressed while the maternal one is silenced. The PWS genes are maternally imprinted making the copy inherited from the father active. With this copy absent in PWS due to chromosomal translocation, both copies are imprinted in the maternal realm making the normal genes absent. Therefore people with PWS have a working and a non-working copy. The characteristics of PWS are stunted development in the intellectual functioning same as those associated with intellectual disability. A chronic feeling of hunger that can lead to excessive hunger and life –threatening obesity arises. Then there is a likelihood of strange behavior or complications that may have effect on ones quality life or on the family members negatively. These ch aracteristics draw the quest for scientific research because the genes which are not expressed and thought to be responsible for the disorder are imprinted. PWS is an example that shows the function of imprinted genes in development. This knowledge has led to extensive research about imprinted genes, their occurrence and process of imprinting. There are two different genotypes for PWS which ultimately lead to two phenotypes, causing the need to understand the causes of the phenotypic differences, identifying the gene and their products and discern whether they are imprinted or no (Butler 12). However, the effects of the syndrome vary from individual to individual and on different factors. This has made the exact nature of the abnormality and whether one or more genes are involved to be unknown. Some physical and behavioral features are inherently present while others are not. The syndrome poses major implications for the developing baby in the uterus and throughout the personâ€℠¢s life. At birth there is extreme floppiness and subsequent cognitive, physical and behavioral abnormalities that eventually lead to widespread medical and social needs. Information on the disorder is got from parents whose children have ever developed it, or medical practitioners who have had such a case. The following are clinical features and signs of PWS at different levels of development: In utero, there is decrease in fetal movement, frequent abnormal fetal position and seldom excessive amniotic fluid, a condition known as polyhydramnios. At birth, there is often caesarian births, difficulties in feeding due to poor muscle tone affecting the sucking process, and respiratory difficulties. At infancy level, the difficulties in feeding advances, oversleeping is evident, crossed eyes and delay in intellectual development. At childhood there are notable delays in speech production, overeating from the age of 2-4 years leading to excessive weight gain and sleeping problems. At adol escence, puberty delays, obesity sets in followed by extreme flexibility and a short physique. In adulthood, infertility is common in males and females, vulnerability to diabetes mellitus, learning disabilities, obesity and reduced growth of pubic hair. The general physical appearance of a PWS adult victim comprise the following characteristics: incomplete sexual development, excess fat on the central part of the body, high, narrow forehead, small hands and feet, light skin and hair unlike other family members, and delayed motor development (Waters 85). Cognitively, PWS patients have low or below average intelligent quotient that is generally unusual. Children portray a high visual and perception capacity on reading and writing with poor articulatory and understanding processes. Coordinating received information word by word is relatively hard for them as well as poor arithmetic skills, leading to memory lapses and auditory retention span. Abnormal behavioral patterns include insati able appetite resulting in increased obesity. The cause for