Prevalence Estimation of Williams Syndrome

Department of Paediatrics, Rikshospitalet, The National Hospital, Oslo, Norway.
Journal of Child Neurology (Impact Factor: 1.72). 05/2002; 17(4):269-71. DOI: 10.1177/088307380201700406
Source: PubMed


There are limited population-based data on the occurrence of Williams syndrome. We estimated its prevalence combining data from two investigations. One was an epidemiologic study originally designed to assess the prevalence and etiology of mental retardation among 30,037 Norwegian children born between 1980 and 1985 and living in Akershus County on January 1, 1993. The other investigation was a national survey of Williams syndrome. In the first study, 213 children were referred for evaluation, whereas the second study comprised 57 cases with Williams syndrome born between 1970 and 1992, who were referred for evaluation from all Norwegian counties. The epidemiologic study revealed three children with Williams syndrome, whereas one additional case complying with our demographic criteria was identified in the national survey, thus giving a prevalence of 1 in 7500. In all cases, a typical chromosome 7q11.23 deletion was detected. We also conclude that Williams syndrome is not an uncommon cause of mental retardation, with a prevalence of approximately 6% of patients with genetic etiology.

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Available from: Petter Strømme, May 12, 2015
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    • "WS is a condition associated with mild ID (Martens et al. 2008), a range of medical conditions (Morris 2005) and an increased risk for difficulties with attention, fears/phobias and social disinhibition (Jones et al. 2000; Leyfer et al. 2006). Estimated prevalence is 1 in 7,500 to 1 in 20,000 (Wang et al. 1997; Stromme et al. 2002). WS is caused by the deletion of approximately 20 genes on chromosome 7 (band 7ql1.23). "
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    ABSTRACT: BackgroundA number of neurogenetic syndromes have a high association with special educational needs including fragile X syndrome (FXS), Prader–Willi syndrome (PWS), Williams syndrome (WS) and Velo-Cardio-Facial syndrome (VCFS). There is a paucity of research on educational provision for children affected by these syndromes.Method Parents (n = 381) and teachers (n = 204) of school-aged children with one of the four syndromes in the UK and Ireland were surveyed in a range of areas concerning the child's educational provision. Areas surveyed included school placement, views on the needs of children with the syndromes, desired changes to current provision and perceived teacher knowledge.ResultsSchool placement in mainstream settings decreased with age in all of the syndromes. Males with the syndromes were more likely to be in specialised educational settings with the exception of WS. Teachers reported limited input on initial or subsequent training for all of the syndromes. The majority of teachers did not view the needs of children with syndromes as different from other children with intellectual disability (ID) although there were significant differences between the syndromes. Changes deemed necessary to provision by parents and teachers differed between the syndromes indicating the existence of perceptions of syndrome specific needs. The lowest perceived level of teacher knowledge was in the VCFS group.Conclusion The majority of teachers of children with neurogenetic syndromes report limited knowledge of the syndromes, but also a lack of belief that the children's needs are different from the majority of children with ID. Differences between the syndromes in some areas of provision suggest that a child's syndrome does impact on educational provision in some areas.
    Journal of Intellectual Disability Research 07/2015; DOI:10.1111/jir.12210 · 2.41 Impact Factor
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    • "WS is considered a segmental aneusomy due to a hemizygous deletion of a contiguous gene at the long arm of chromosome 7 (7q11.23) (Stromme et al. 2002). Most individuals with WS (99%) have a 1.5 mega base deletion in 7q11.23 encompassing the elastin gene (ELN) and 26-28 other genes (Kozel et al. 2014) all of which is detectable by fluorescent in situ hybridization (FISH) (Wiliams and Lind 2012). "
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    ABSTRACT: Williams syndrome (OMIM 194050) is a rare multisystem genetic disorder with an incidence of 1/ 75000 which usually occurs sporadically caused by the deletion of 26 contiguous genes, including elastin (ELN) (OMIM 130160) on chromosome 7q11.23. The researchers present here three cases of Williams syndrome with cardiac anomalies and varying clinical presentation. In this paper the researchers suggest a defined protocol with more attention while evaluating cardiac anomalies in childhood period, especially when the patient has facial dysmorphism or developmental delay.
    International Journal of Human Genetics 06/2015; 15(2):51-54. · 0.37 Impact Factor
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    • "Williams syndrome (WS) is a relatively rare genetically based neurodevelopmental disorder with estimates of prevalence between 1 in 7500 and 1 in 20,000 births (Stromme et al., 2002). The disorder is caused by a de novo microdeletion on the long arm of chromosome 7, specifically 7q11.23 (Ewart et al., 1993). "
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    ABSTRACT: Williams syndrome (WS) is associated with a distinct profile of relatively proficient skills within the verbal domain compared to the severe impairment of visuo-spatial processing. Abnormalities in executive functions and deficits in planning ability and spatial working memory have been described. However, to date little is known about the influence of executive function deficits on navigational abilities in WS. This study aimed at analyzing in WS individuals a specific executive function, the backward inhibition (BI) that allows individuals to flexibly adapt to continuously changing environments. A group of WS individuals and a mental age-and gender-matched group of typically developing children were subjected to three task-switching experiments requiring visuospatial or verbal material to be processed. Results showed that WS individuals exhibited clear BI deficits during visuospatial task-switching paradigms and normal BI effect during verbal task-switching paradigm. Overall, the present results suggest that the BI involvement in updating environment representations during navigation may influence WS navigational abilities.
    Frontiers in Psychology 04/2015; 6. DOI:10.3389/fpsyg.2015.00287 · 2.80 Impact Factor
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