- The Fragile X syndrome (FXS, OMIM #300624) represents the most common cause of hereditary intellectual disability, affecting both sexes.
- Its prevalence is estimated at around 1/4,000 for boys and 1/6,000 for girls, the masculine form usually being more severe.
- FXS is the most common cause of hereditary intellectual disability, bringing about an overall problem in reasoning as well as autistic problems.
- The term “fragile site” linked to the X chromosome was introduced by Frédérick Hecht in the 1970s.
+ Further information can be found on the Jérôme Lejeune Institute website