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 rare developmental disorder with estimates of prevalence usually given as 1 in 20,000 live births, although a subsequent population study reported a prevalence of 1 in 7,500 (Strømme et al., 2002). This discrepancy may reflect better diagnosis of the unique clinical features such as characteristic facial and behavioural features, alongside the gold standard diagnostic test, fluorescent in-situ hybridization (FISH), commonly indicating deletion of the elastin (ELN) gene. "
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    DESCRIPTION: Chapter to appear in 'Developmental Disorders of the Brain'
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    • "distinctive elfin facial features, a hoarse voice associated with overfriendly personality, growth and intellectual disability, hyperacusis, infantile hypercalcemia, and prematurely wrinkled skin are also common symptoms [Karmiloff-Smith et al., 2003]. WBS is generally sporadic with frequency of approximately one in 7,500 live births with no ethnic or sex preference, although familial cases have been reported with apparent autosomal dominant inheritance [Strømme et al., 2002]. Despite the consistency of the overall clinical features, the broad spectrum of anomalies and phenotypic variability frequently lead to a significant difference in the number of patients diagnosed [Ashkenas, 1996]. "
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    ABSTRACT: Williams-Beuren syndrome (WBS) is caused by a hemizygous contiguous gene microdeletion of 1.55-1.84 Mb at 7q11.23 region. Approximately, 28 genes have been shown to contribute to classical phenotype of SWB with presence of dysmorphic facial features, supravalvular aortic stenosis (SVAS), intellectual disability, and overfriendliness. With the use of Microarray-based comparative genomic hybridization and other molecular cytogenetic techniques, is possible define with more accuracy partial or atypical deletion and refine the genotype-phenotype correlation. Here, we report on a rare genomic structural rearrangement in a boy with atypical deletion in 7q11.23 and XYY syndrome with characteristic clinical signs, but not sufficient for the diagnosis of WBS. Cytogenetic analysis of G-banding showed a karyotype 47,XYY. Analysis of DNA with the technique of MLPA (Multiplex Ligation-dependent Probe Amplification) using kits a combination of kits (P064, P036, P070, and P029) identified an atypical deletion on 7q11.23. In addition, high resolution SNP Oligonucleotide Microarray Analysis (SNP-array) confirmed the alterations found by MLPA and revealed others pathogenic CNVs, in the chromosomes 7 and X. The present report demonstrates an association not yet described in literature, between Williams-Beuren syndrome and 47,XYY. The identification of atypical deletion in 7q11.23 concomitant to additional pathogenic CNVs in others genomic regions allows a better comprehension of clinical consequences of atypical genomic rearrangements. © 2015 Wiley Periodicals, Inc.
    American Journal of Medical Genetics Part A 09/2015; DOI:10.1002/ajmg.a.37360 · 2.16 Impact Factor
    • "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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