Wednesday, August 21, 2019
Williams Syndrome A Genetic Disorder Psychology Essay
Williams Syndrome A Genetic Disorder Psychology Essay Williams Syndrome is a genetic disorder that is caused by a deletion of genes on chromosome seven. It is a rare disorder, occurring in about every 1 in 20,000 births and affects males and females equally. Small upturned nose, wide mouth, full lips, small wide-spaced teeth, a relatively low IQ, cardiovascular disease and an irregular cognitive profile are some classifications of Williams Syndrome. (Laing, Butterworth, Ansari, Gsodl, Longhi, Panagiotaki, et al., 2002). Many of the physical features of Williams Syndrome are due to the deletion of the gene elastin on chromosome seven. There are some aspects of language that appear to be intact for those with Williams Syndrome including social interaction, however, spatial language, number, planning and problem solving appear to be impaired in most individuals (Laing et al., 2002). Not all features of language are affected in children and adults with Williams Syndrome. Williams Syndrome has a characteristic language delay and there is evidence to suggest that language development follows an alternate pathway than what is seen in language development of a typical child (Laing et al., 2002). Laing et al. performed three experiments in order to assess joint attention, pointing and precision grips. The same children were used over the course of all three experiments and mental age of typically developing children was calculated to match those in the Williams Syndrome group. In the first experiment it was found that the children with Williams Syndrome performed atypically on tasks set to deduce the level of joint attention these children were providing. The second experiment administered was used to establish credibility findings of the first experiment. The researchers are observing if the children with Williams Syndrome can establish reference and therefore test t heir ability to point in response to specific stimuli. Laing et al. found that children with Williams Syndrome produced few pointing behaviors. The third experiment determined if the reason for the difference in pointing between the control group and the Williams Syndrome group was due to impaired motor skills. This was found to not be an issue as the children with Williams Syndrome and those in the control group were relatively similar in their motor skills. These issues in joint attention are thought to be part of the reason there is a language delay among children with Williams Syndrome as joint attention and pointing are both critical in language development (Laing et al., 2002). A study performed by Mervis and John (2008) was designed to tests strengths and weaknesses of children with Williams Syndrome with their vocabulary abilities. Mervis and John performed three experiments in order to determine the specific strengths and weaknesses in abilities of Williams Syndrome children in relation to vocabulary. The first experiment used the following standardized tests; the Kaufman Brief Intelligence Test (vocabulary and matrices) the Peabody Picture Vocabulary Test-third edition (concrete vocabulary, including object names, action words, and descriptors) and the Test of Relational Concepts (conceptual/relational language). The first experiment compared typically developing children against Williams Syndrome children in two assessments of vocabulary: concrete vocabulary and conceptual/relational vocabulary. Mervis and John found that the Williams Syndrome group performed better on concrete vocabulary than conceptual/relational vocabulary. Even though the scores fo r children on concrete vocabulary were high for children with Williams Syndrome, performance on these tests showed signs that even this area of language is not completely undamaged. The second experiment took the results of the first three standardized tests and included the Differential Ability Scales Pattern Construction subtest. Mervis and John examined the relation between conceptual/relational language comparative of visuospatial construction. The children with Williams syndrome performed better on tests related to conceptual/relational language as compared to scores on the visuospatial construction tasks. Mervis and John (2008) note that Williams Syndrome is distinguished by strengths and weaknesses within the vocabulary element of language. The third experiment used the formulated sentences subtest on the Clinical Evaluation of Language Fundamentals-fourth edition (CELF-4), in order to evaluate a variety of relational concepts. This experiment measured the knowledge of some m ore evolved relational concepts using the CELF-4. It was concluded that not all, but most children with Williams Syndrome have difficulty in simple relational words and it encompasses both relational terms meant to link two words or short phrase and also to relational terms meant to connect simple sentences into one complex sentence (Mervis and John, 2008). Mervis and John determined that children with Williams Syndrome do seem to have strength in vocabulary in general but rather concrete vocabulary. Laing and Jarrold (2007) sought to determine the spatial language skills of children with Williams Syndrome as compared to typically developing children. While noting that some aspects of language are usually intact for children with Williams Syndrome, spatial skills and non-verbal skills are usually the most impaired. In this experiment, the sample included 17 children with Williams Syndrome and 17 children that were classified as typically developing. There were several tests administered: Picture matching tasks, semantic picture matching, Spatial picture matching, grammatical knowledge task, perception task, naming task, and animal knowledge task. The test was given on a computer that displayed 4 pictures at the same time. There was a target sentence presented for each trial, which appeared on the screen and changed depending on the task. Results found that the Williams Syndrome group and the typically developing group performed with no significant differences on any measure excep t perception scores. There was also found to be a significant difference between the groups on the spatial picture-matching task. Due to the problems with understanding the semantics of spatial skills, it was hypothesized that this lends to problems in language processing in general (Laing Jarrold, 2007). For those with Williams Syndrome, there may be a great effort to form appropriate spatial mental models that may form the foundation for the production and comprehension of verbal descriptions of space (Laing Jarrold, 2007). Research performed by Laws and Bishop (2004) studied social communication, which is normally thought of as a relative strength for the Williams Syndrome population. Laws and Bishop performed a study on the different pragmatic facets of language. Groups of 19 children with Williams Syndrome, 24 with Downs Syndrome, 17 with specific language impairment and 32 typically developing children were studied. The Childrens Communication Checklist (CCC) was used in order to obtain data on social interaction for these four groups. On the checklist, there are two subscales that describe speech production: speech output and syntax. There are five subscales that describe the childs communication behaviors: inappropriate initiation, coherence, stereotyped conversation, use of conversational context conversational rapport. Two more subscales assess aspects of development: social relationships and interests. The raters were asked to respond to these items and rate them on a scale of four possibilitie s: does not apply, applies somewhat, definitely applies and unable to judge (Laws Bishop). When analyzed, experimenters found that individuals with Williams Syndrome had pragmatic impairments. The areas that were found to be the most impacted were the inappropriate initiation of conversation and the use of stereotyped conversation (Laws Bishop, 2004). The children do however have very strong expressive language skills and tend to be very social individuals (Laws Bishop, 2004). Since Williams Syndrome is a rare genetic disorder occurring in every 1 in 20,000 live births more information is needed regarding their communicative abilities. There is evidence to suggest that their language delay is due information traveling through a different pathway than with typically developing children. Spatial language is also a problem that with intervention can be improved along with conceptual and relational vocabulary. Pragmatic language is an issue, however the Williams Syndrome population tends to be overly friendly and very strong expressively. It was found that as these issues seem to dissipate in adulthood as well as the Williams Syndrome population, depending on the severity level, these children can live independently or with support.
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