Article Text

PDF
Partial 7q11.23 deletions further implicate GTF2I and GTF2IRD1 as the main genes responsible for the Williams–Beuren syndrome neurocognitive profile
  1. A Antonell1,
  2. M Del Campo1,2,
  3. L F Magano1,
  4. L Kaufmann3,4,
  5. J Martínez de la Iglesia5,
  6. F Gallastegui1,
  7. R Flores1,
  8. U Schweigmann6,
  9. C Fauth7,
  10. D Kotzot7,
  11. L A Pérez-Jurado1,2
  1. 1Unitat de Genètica, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, and CIBER de enfermedades raras (CIBERER), Barcelona, Spain
  2. 2Programa de Medicina Molecular i Genètica, Hospital Vall d'Hebron, Barcelona, Spain
  3. 3Clinical Department of Pediatrics IV, Medical University Innsbruck, Innsbruck, Austria
  4. 4Department of Psychology, University of Salzburg, Salzburg, Austria
  5. 5Centro de Salud Lucano, Córdoba, Spain
  6. 6Clinical Department of Pediatrics I, Medical University Innsbruck, Innsbruck, Austria
  7. 7Division of Clinical Genetics, Medical University Innsbruck, Innsbruck, Austria
  1. Correspondence to Luis A Pérez-Jurado, Unitat de Genètica, Universitat Pompeu Fabra, Parc de Recerca Biomèdica de Barcelona (PRBB), C/Dr Aiguader, 88, Barcelona 08003, Spain; luis.perez{at}upf.edu

Abstract

Background Williams–Beuren syndrome (WBS) is a developmental disorder with multisystemic manifestations mainly characterised by vascular stenoses, distinctive craniofacial features, mental retardation with a characteristic neurocognitive profile, and some endocrine and connective tissue abnormalities, caused by a recurrent deletion of 1.55 Mb including 26–28 genes at chromosomal region 7q11.23. The analysis of clinical–molecular correlations in a few reported atypical patients has been useful to propose several deleted genes as main contributors to specific aspects of the WBS phenotype.

Patients and methods Two additional families with partial phenotypes and atypical 7q11.23 deletions were studied. Deletions were precisely defined at the nucleotide level, and the expression levels of some affected and flanking genes were assessed in lymphoblastoid cell lines.

Results Affected individuals presented variable cardiovascular and connective tissue manifestations, subtle craniofacial features, normal visuospatial construction abilities with low average IQ and no endocrine abnormalities. The deletion in family NW1 encompassed 817 kb with 11 genes (CLDN3GTF2IRD1), and 610 kb with 14 genes (VPS37DRFC2) in family NW2. All deleted genes in typical and atypical deletions revealed low expression levels in lymphoblastoid cell lines, except for GTF2IRD1. CLIP2 was also underexpressed in all patients despite being outside the deletion in NW2, while no other flanking non-deleted gene showed significantly different expression compared to controls.

Conclusions Along with previously reported cases, clinical–molecular correlations in these two families further confirm that the functional hemizygosity for the GTF2I and GTF2IRD1 genes is the main cause of the neurocognitive profile and some aspects of the gestalt phenotype of WBS.

  • Williams–Beuren syndrome (WBS)
  • partial deletion
  • visuospatial construction
  • mental retardation
  • genetics
  • clinical genetics
  • cytogenetics
  • molecular genetics
  • visual development

Statistics from Altmetric.com

Footnotes

  • Competing interests None.

  • Patient consent Obtained.

  • Ethics approval This study was conducted with the approval of the Clinical Research Ethics Committee from IMIM/UPF/PRBB (http://www.imim.es/comitesetics/en_index.html).

  • Provenance and peer review Not commissioned; externally peer reviewed.

Request permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.