Gender Differences in Fragile X Syndrome | Vibepedia

Fragile X syndrome (FXS), a leading genetic cause of intellectual disability and autism, exhibits profound gender-based differences in its clinical manifestation and severity. Primarily caused by an expansion of CGG repeats in the FMR1 gene on the X chromosome, FXS affects males more severely than females due to the presence of two X chromosomes in females, which can often compensate for the mutation. While males typically experience significant intellectual disability, characteristic physical features, and higher rates of autism, females often present with milder symptoms, a wider range of intellectual abilities, and sometimes no overt signs of the disorder. This disparity stems from X-chromosome inactivation, a process where one of the two X chromosomes in female cells is randomly silenced, potentially leaving some cells with a functional FMR1 gene. Understanding these differences is crucial for accurate diagnosis, targeted interventions, and comprehensive genetic counseling.