Williams syndrome
From Wikipedia, the free encyclopedia
| Williams syndrome Classification and external resources |
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| ICD-10 | Q93.8 |
|---|---|
| ICD-9 | 758.9 |
| OMIM | 194050 |
| MedlinePlus | 001116 |
| eMedicine | ped/2439 |
| MeSH | D018980 |
Williams syndrome (also Williams-Beuren syndrome) is a rare genetic disorder,[1] occurring in about 1 in 7,500 live births.[2] It is characterized by a distinctive, "elfin" facial appearance, along with a low nasal bridge; an unusually cheerful demeanor and ease with strangers, coupled with unpredictably occurring negative outbursts; mental retardation coupled with unusual (for persons who are diagnosed as mentally retarded) language skills; a love for music; and cardiovascular problems, such as supravalvular aortic stenosis and transient hypercalcaemia. The syndrome was first identified in 1961 by Dr. J. C. P. Williams of New Zealand. [3]
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[edit] Symptoms
Williams syndrome shares some similarities with autism (such as difficulty understanding the state of mind of conversational partners[4]) and fetal alcohol syndrome (e.g., certain facial features, possible learning disabilities, and negative potential outbursts),[5] although persons with Williams generally possess very good social skills, such that this condition is sometimes called "cocktail-party syndrome". There also appears to be a higher prevalence of left-handedness and left-eye dominance in those with Williams,[6] and cases of absolute pitch appear to be significantly higher amongst those with the condition.[7]
[edit] Relativity and perception
Another symptom of Williams syndrome is lack of depth perception and an inability to visualize how different parts assemble into larger objects (in assembling jigsaw puzzles, for example). This problem is caused by a defect in the brain that creates a sparsity of tissue in the visual systems of the brain. When asked to perform tasks involving spatial relations, with their brains scanned by fMRI, people with Williams Syndrome showed weaker activity in the dorsal area of the brain, which is along the top and back of the brain and associated with vision and spatial relations.[citation needed] (fMRI measures brain activity by measuring blood flow through different parts of the brain.)
When asked to copy a picture, those with Williams Syndrome drew the small details while those diagnosed with Down Syndrome drew the big picture (Navon Task).[8]
[edit] Cause
| Williams Syndrome genes[9][10] | |
|---|---|
| ASL · BAZ1B · BCL7B · CLDN3 · CLDN4 CLIP2 · EIF4H · ELN · FZD9 · FKBP6 GTF2I · GTF2IRD1 · HIP1 · KCTD7 LAT2 · LIMK1 · MDH2 · NCF1 NSUN5 · POR · RFC2 · STX1A · TBL2 TRIM50 · TRIM73 · TRIM74 WBSCR14 · WBSCR18 · WBSCR21 WBSCR22 · WBSCR23 · WBSCR24 WBSCR27 · WBSCR28 |
Williams syndrome is caused by the deletion of genetic material from the region q11.23 of chromosome 7. The deleted region includes more than 20 genes, and researchers believe that the loss of several of these genes probably contributes to the characteristic features of this disorder. CLIP2, ELN, GTF2I, GTF2IRD1, and LIMK1 are among the genes that are typically deleted in people with Williams syndrome. Researchers have found that loss of the ELN gene, which codes for the protein elastin, is associated with the connective-tissue abnormalities and cardiovascular disease (specifically supravalvular aortic stenosis (SVAS) and supravalvular pulmonary stenosis (SVPS)) found in many people with this syndrome. Studies suggest that deletion of LIMK1, GTF2I, GTF2IRD1, and perhaps other genes may help explain the characteristic difficulties with visual–spatial tasks. Additionally, there is evidence that the loss of several of these genes, including CLIP2, may contribute to the unique behavioral characteristics, learning disabilities, and other cognitive difficulties seen in Williams syndrome.
[edit] In popular culture
Williams syndrome was featured in a 2007 episode of Law & Order: Special Victims Unit entitled "Savant," in which a girl with the condition is the only witness to the attack of her mother. The girl did not see the attacker but heard him speak, and her absolute pitch helped the police catch her mother's assailant.
In the Wes Anderson film The Royal Tenenbaums, the character of Dudley has fictional Heinsbergen Syndrome, which features many similarities with Williams syndrome. Dudley has difficulty understanding spatial relations (dyslexia, colorblindness, inability to solve puzzles) coupled with an acute sense of hearing.
In the season 4 episode 13, No More Mr. Nice Guy, of the television program House, Dr. House incorrectly diagnosed a patient with Williams syndrome based on a suspected genetic inability to identify suspect causes, leading to the patient's "niceness".
[edit] References
- ^ Williams Syndrome Information Page. National Institute of Neurological Disorders and Stroke (February 14, 2007). Retrieved on 2007-09-13.
- ^ Stromme Petter, Bjornstad Per G, Ramstad Kjersti (2002). "Prevalence estimation of Williams syndrome". Journal of child neurology 17 (4): 269-71. doi:. PMID 12088082.
- ^ Dobbs, David. "The Gregarious Brain.", New York Times, July 8, 2007. Retrieved on 2007-09-25. "If a person suffers the small genetic accident that creates Williams syndrome, he’ll live with not only some fairly conventional cognitive deficits, like trouble with space and numbers, but also a strange set of traits that researchers call the Williams social phenotype or, less formally, the “Williams personality”: a love of company and conversation combined, often awkwardly, with a poor understanding of social dynamics and a lack of social inhibition."
- ^ Rhitu Chatterjee. "Rare Disorder Offers Fresh Insight into Language Rhitu Chatterjee", National Public Radio, 10 Jul 2006.
- ^ Fetal Alcohol Syndrome: Guidelines for Referral and Diagnosis. CDC (2004).
- ^ Van Strien JW, Lagers-Van Haselen GC, Van Hagen JM, De Coo IF, Frens MA, Van Der Geest JN (2005). "Increased prevalences of left-handedness and left-eye sighting dominance in individuals with Williams-Beuren syndrome". J Clin Exp Neuropsychol 27 (8): 967–76. doi:. PMID 16207621.
- ^ Sacks O (May 1995). "Musical ability". Science 268 (5211): 621–2. doi:. PMID 7732360.
- ^ Bihrle AM, Bellugi U, Delis D, Marks S (1989). "Seeing either the forest or the trees: dissociation in visuospatial processing". Brain Cogn 11 (1): 37–49. doi:. PMID 2528973.
Cited by- Robert Finn. "Different Minds" (reprint), Discover magazine, June 1991.
- Ágnes Lukács. Language Abilities in Williams Syndrome (DOC). - dissertation
- Dagmara Annaz. The Development of Visuo-spatial Processing in children with Autism, Down Syndrome, and Williams Syndrome (PDF). - thesis
- ^ Merla G, Howald C, Henrichsen CN, et al (August 2006). "Submicroscopic deletion in patients with Williams-Beuren syndrome influences expression levels of the nonhemizygous flanking genes". Am. J. Hum. Genet. 79 (2): 332–41. doi:. PMID 16826523.
- ^ Schubert C, Laccone F (November 2006). "Williams-Beuren syndrome: determination of deletion size using quantitative real-time PCR". Int. J. Mol. Med. 18 (5): 799–806. PMID 17016608.
[edit] Further reading
- Williams JC, Barratt-Boyes BG, Lowe JB (1961). Supravalvular aortic stenosis. Circulation 24:1311-1318.
- Beuren AJ, Apitz J, Harmjanz D (1962). Supravalvular aortic stenosis in association with mental retardation and a certain facial appearance. Circulation 26:1235-1240.
- Beuren AJ (1972). Supravalvular aortic stenosis: a complex syndrome with and without mental retardation. Birth defects Orig Art Ser VIII 5:45-56.
- Bellugi U, Lichtenberger L, Mills D, Galaburda A, Korenberg JR (1999). Bridging cognition, the brain and molecular genetics: evidence from Williams syndrome. Trends Neurosci 22:197-207.
[edit] External links
- David Dobbs. "The Gregarious Brain", New York Times Magazine, July 8, 2007.
- Health Care Supervision for Children with Williams Syndrome
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