Article Text

Download PDFPDF
General overgrowth in the fragile X syndrome: variability in the phenotypic expression of the FMR1 gene mutation
  1. Bert B A de Vries1,
  2. Hazel Robinson2,
  3. Irene Stolte-Dijkstra3,
  4. Cecil V Tjon Pian Gi4,
  5. Piet F Dijkstra5,6,
  6. Jaap van Doorn7,
  7. Dicky J J Halley1,
  8. Ben A Oostra1,
  9. Gillian Turner2,
  10. Martinus F Niermeijer1
  1. Department of Clinical Genetics, University Hospital Dijkzigt and Erasmus University, Rotterdam, The Netherlands
  2. Fragile X Department, Prince of Wales Hospital, Randwick, NSW, Australia
  3. Department of Medical Genetics, University of Groningen, Groningen, The Netherlands
  4. Department of Paediatrics, Hospital Groene Hart, Gouda, The Netherlands
  5. Department of Röntgenology, Jan van Breemen Institute, Center for Rheumatology and Rehabilitation, Amsterdam, The Netherlands
  6. Academic Medical Centre, Amsterdam, The Netherlands
  7. Department of Endocrinology, Wilhelmina's University Hospital for Children and Youth, Utrecht, The Netherlands


    The fragile X syndrome, which often presents in childhood with overgrowth, may in some cases show some diagnostic overlap with classical Sotos syndrome. We describe four fragile X patients with general overgrowth, all of whom are from families with other affected relatives who show the classic Martin-Bell phenotype. Molecular studies of the FMR1 gene in all cases showed the typical full mutation as seen in males affected by the fragile X syndrome. Endocrine studies were unremarkable, except in one case where there were raised levels of insulin-like growth factor-I (IGF-I) and insulin-like growth factor binding protein-3 (IGFBP-3)

    These cases illustrate the clinical variability of the fragile X syndrome and the necessity of performing analysis of the FMR1 gene in mentally retarded patients presenting with general overgrowth.

    Statistics from

    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.