Biology - Prader-Willi Syndrome - Research Paper Example

?Prader–Willi Syndrome Introduction 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 characteristics 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 person’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 adolescence, 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 insatiable appetite resulting in increased obesity. The cause for this has not been proven although it is alleged that the deletion of chromosome 15 affects the functioning of the hypothalamus. Skin picking, anxiety, depression and hallucinations are also evident. Genetically, the disorder occurs as a result of chance mutation, chromosome translocations, and gene deletions. The risk of infected patient is dependent on the factor that caused the disorder. Testing the parent can deduce the cause of the disorder to the child (Caldwell & Taylor 60). Diagnosis It mostly focuses on neurodevelopmental, neurocognitive and developmental aspects of PWS including behavior and crisis management, educational concerns, vocational and accommodation options. Early diagnosis such as growth hormone therapy can increase the chances of change. Symptoms vary from mild to severe in a person lifetime. It has also been discovered that the disease can affect various organs of the body. Earlier on, the disorder was treated by clinical presentation while today; it is done through genetic testing especially for newborns with pronounced hyptonia. Daily prescription of growth hormone is indicated for children patients. Growth hormone injections increases muscle mass; reduce appetite as well as weight gain and support linear growth. Genetic testing is done to s determine the absence of the paternal gene that contributes to the syndrome on chromosome 15. The test is done in all individuals most specifically on very young children to detect those characteristics. PWS Infants have a very high vulnerability to other complications at birth such as caesarian delivery and respiratory problems, injuries at birth, suffocation resulting in full blown PWS (Whittington 14). Treatment Prader-willi syndrome has no cure, making several treatments available to reduce the symptoms. Constant therapies should be administered during infancy to improve muscle tone. These include speech and occupational therapy. Conducive coupled with sophisticated learning environment is recommended in children as well as extra care to cater for the low intellectual capacities. With severe obesity being the most dangerous problem associated with the disorder, regular exercise, proper diet habits and increased physical activity should be the norm. The goal of treatment should be to achieve and maintain healthier weight not necessarily an ideal weight. Other medical findings show that PWS patients have less bone density which may cause fractures. Increasing he density occurs through a process called bone resorption and production of bone matrix containing minerals. Decrease in bone matrix can be detected by measuring urinary N-telopeptides of type 1 collagen. Mineral bone content and body composition can be determined by dual energy X-ray absorptiometry (DXA). Thick and sticky saliva is detected during the early days of PWS development increasing tooth wear by erosion and abrasion. The condition is facilitated by genetic imprinting. Patients should regularly seek dental medication to treat dental related problems (Holm & Stephen 154). Self injurious behaviors evident among the patients are eye poking, banging the head on surfaces and walls, skin picking and rectal picking. Others are biting, pinching and hitting that occurs on body parts as legs, arms and fingers. These can be approached by dopaminergic system, serotonergic systems and endogenous opioid peptide systems. Works Cited Jackie Waters. An examination of the cognitive, medical and psychological aspects. Print. Joyce Whittington & Tony Holand. Development and Manifestations: Cambridge University Press. Print. Mary Caldwell & Ronald Taylor, Selected Research and Management Issue: Prader-Willi Syndrome, Springer Verlag. Print. Merlin Butler, Management of Prader-Willi Syndrome , Prader- Willi Syndrome Association.Print. Vanja Holm & Stephen Sulzbcher. prader-willi syndrome: University Park Press. Print. Read More