Article Text

Download PDFPDF
The fragile X syndrome: no evidence for any recent mutations.
  1. A P Smits,
  2. J C Dreesen,
  3. J G Post,
  4. D F Smeets,
  5. C de Die-Smulders,
  6. T Spaans-van der Bijl,
  7. L C Govaerts,
  8. S T Warren,
  9. B A Oostra,
  10. B A van Oost
  1. Department of Human Genetics, University Hospital Nijmegen, The Netherlands.

    Abstract

    Fragile X (fra(X)) syndrome, the most common form of familial mental retardation, is caused by heritable unstable DNA composed of CGG repeats. As reproductive fitness of fra(X) patients is severely compromised, a high mutation rate has been proposed to explain the high prevalence. However, we have been unable to show any new mutation for 84 probands referred to us to date. We show here the same fra(X) gene in five fra(X) probands with common ancestors married in 1747. The lack of new fra(X) mutations implies that there must be many more fra(X) gene carriers in the population than previously realised. As it is now possible to detect asymptomatic fra(X) gene carriers by DNA analysis, extended family studies for any new proband are recommended. A family illustrating the importance of fra(X) carriership determination is reported.

    Statistics from Altmetric.com

    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.