- Williams syndrome
Infobox_Disease
Name = Williams syndrome
Caption =
DiseasesDB =
ICD10 = ICD10|Q|93|8|q|90
ICD9 = ICD9|758.9
ICDO =
OMIM = 194050
MedlinePlus = 001116
eMedicineSubj = ped
eMedicineTopic = 2439
MeshID = D018980Williams syndrome (WS; also Williams-Beuren syndrome or WBS) is a rare
neurodevelopmental disorder caused by a deletion of about 26 genes from the long arm ofchromosome 7 . 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; a predisposition to violent outbursts;mental retardation coupled with unusual (for persons who are diagnosed as mentally retarded)language skills; a love formusic ; and cardiovascular problems, such assupravalvular aortic stenosis and transienthypercalcaemia . The syndrome was first identified in 1961 by Dr.J. C. P. Williams ofNew Zealand . [cite news |first=David |last=Dobbs |authorlink= |coauthors= |title=The Gregarious Brain. |url=http://www.nytimes.com/2007/07/08/magazine/08sociability-t.html |quote=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. |publisher=New York Times |date=July 8 ,2007 |accessdate=2007-09-25 ]ymptoms
Individuals with Williams syndrome are highly verbal and sociable, but lack common sense and typically have low intelligence. The condition has been contrasted with
autism , who lack social interests. Individuals with WS hyperfocus on the eyes of others in social engagements. [cite journal |author=Riby DM, Hancock PJ |title=Viewing it differently: Social scene perception in Williams syndrome and Autism |journal=Neuropsychologia |volume=46 |issue=11 |pages=2855–60 |year=2008 |pmid=18561959 |doi=10.1016/j.neuropsychologia.2008.05.003 |url=] There also appears to be a higher prevalence ofleft-handedness and left-eye dominance in those with Williams,cite journal |author=Van Strien JW, Lagers-Van Haselen GC, Van Hagen JM, De Coo IF, Frens MA, Van Der Geest JN |title=Increased prevalences of left-handedness and left-eye sighting dominance in individuals with Williams-Beuren syndrome |journal=J Clin Exp Neuropsychol |volume=27 |issue=8 |pages=967–76 |year=2005 |pmid=16207621 |doi=10.1080/13803390490919119] and cases of absolute pitch appear to be significantly higher amongst those with the condition.cite journal |author=Sacks O |authorlink=Oliver Sacks |title=Musical ability |journal=Science |volume=268 |issue=5211 |pages=621–2 |year=1995 |month=May |pmid=7732360|doi=10.1126/science.7732360] People with Williams syndrome often havehyperacusis andphonophobia which resemblesnoise-induced hearing loss , but this may be due to a malfunctioning auditory nerve. [cite journal |author=Gothelf D, Farber N, Raveh E, Apter A, Attias J |title=Hyperacusis in Williams syndrome: characteristics and associated neuroaudiologic abnormalities |journal=Neurology |volume=66 |issue=3 |pages=390–5 |year=2006 |month=February |pmid=16476938 |doi=10.1212/01.wnl.0000196643.35395.5f |url=http://www.neurology.org/cgi/pmidlookup?view=long&pmid=16476938] [cite journal |author=Johnson LB, Comeau M, Clarke KD |title=Hyperacusis in Williams syndrome |journal=J Otolaryngol |volume=30 |issue=2 |pages=90–2 |year=2001 |month=April |pmid=11770962 |doi= |url=] Individuals with Williams syndrome also report higher levels of fears, which may be associated with hyperacusis. [cite journal |author=Blomberg S, Rosander M, Andersson G |title=Fears, hyperacusis and musicality in Williams syndrome |journal=Res Dev Disabil |volume=27 |issue=6 |pages=668–80 |year=2006 |pmid=16269236 |doi=10.1016/j.ridd.2005.09.002 |url=]Visual perception
Individuals with Williams syndrome have difficulties with
visual processing , but this is related to how complex spatial relationships are rather than issues withdepth perception . [cite journal |author=Van der Geest JN, Lagers-van Haselen GC, van Hagen JM, "et al" |title=Visual depth processing in Williams-Beuren syndrome |journal=Exp Brain Res |volume=166 |issue=2 |pages=200–9 |year=2005 |month=October |pmid=15965761 |doi=10.1007/s00221-005-2355-1 |url=]Cause
Infobox generic
name = Williams Syndrome genescite journal |author=Merla G, Howald C, Henrichsen CN, "et al" |title=Submicroscopic deletion in patients with Williams-Beuren syndrome influences expression levels of the nonhemizygous flanking genes |journal=Am. J. Hum. Genet. |volume=79 |issue=2 |pages=332–41 |year=2006 |month=August |pmid=16826523 |doi=10.1086/506371 |url=] cite journal |author=Schubert C, Laccone F |title=Williams-Beuren syndrome: determination of deletion size using quantitative real-time PCR |journal=Int. J. Mol. Med. |volume=18 |issue=5 |pages=799–806 |year=2006 |month=November |pmid=17016608 |doi= |url=http://www.spandidos-publications.com/ijmm/article.jsp?article_id=ijmm_18_5_799] |
style1 = style="text-align:center; font-size:90%;"
row1 = 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 20gene s, and researchers believe that the loss of several of these genes probably contributes to the characteristic features of this disorder. Gene|CLIP2, ELN, Gene|GTF2I, Gene|GTF2IRD1, and Gene|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 proteinelastin , 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.Management
Guidelines published by the American Academy of Pediatrics include cardiology evaluations, anethesia consultation for any child requiring surgery, developmental and psychoeducational assessment, and many other examination, laboratory, and anticipatory guidance recommendations. [cite journal |journal=Pediatrics |year=2001 |volume=107 |issue=5 |pages=1192–2004 |title= Health care supervision for children with Williams syndrome |author= Committee on Genetics, American Academy of Pediatrics |url=http://aappolicy.aappublications.org/cgi/content/full/pediatrics;107/5/1192]
Epidemiology
Williams syndrome has an estimated
prevalence of 1 in 7,500 to 1 in 20,000.cite journal |journal= J Child Psychol Psychiatry |year=2008 |volume=49 |issue=6 |pages=576–608 |title= Research Review: Williams syndrome: a critical review of the cognitive, behavioral, and neuroanatomical phenotype |author= Martens MA, Wilson SJ, Reutens DC |doi=10.1111/j.1469-7610.2008.01887.x |pmid=18489677]References
Further reading
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