latest news
  • Video Launch - Challenging Behaviour

    We have launched a new video on the factors that...

  • Mental health difficulties in children with learning disabilities

    Overview of the presentation

    This presentation was delivered by Chris...

  • Challenging behaviour in fragile-X syndrome

    Presenter: Dr Jane Waite

    Date of presentation: 24th September...

  • Exciting New Research in Autism Launched Today

    A new research study...

Key Fact
Fragile X syndrome is more common in males than in females, due to it being an X-linked disorder.

History and Prevalence of Fragile X Syndrome


The prevalence of fragile X syndrome differs between males and females, with estimates of 1 in 4000 for males and 1 in 8000 for females.



 James Purdon Martin and Julia Bell first described fragile X syndrome in 1943. They reported a family case study in which intellectual disability appeared to be inherited and linked to the X chromosome.

In 1969, Herbert Lubs made the observation of a characteristic fragile site on the lower end of the X chromosome.

The FMR1 gene on the X chromosome that is associated with fragile X syndrome was identified and sequenced in 1991. To read more about the genetics of fragile X syndrome, click here.



Download this page as a PDF