Fragile X Syndrome

Fragile X syndrome (FXS} is the most common inherited cause of intellectual disabilities and the leading single-gene cause of autism spectrum disorder. FXS can impact many aspects of daily Iife, including an individual's ability to care for themselves and communicate with others. 

FXS is caused by a genetic mutation of the FMRl gene on the X chromosome, with manifestations that can vary greatly across individuals. Males have only one X chromosome, so when that chromosome carries the Fragile X mutation, they often experience substantial intellectual challenges. Since females have two X chromosomes, when one is a "Fragile X" chromosome and the other is unaffected, the unaffected X chromosome may compensate, resulting in females with FXS often being less affected than males. 

Learn about Shionogi's research in Fragile X syndrome.