Will more than one family member suffer from fragile x syndrome?

Possibly: It's a genetic problem, passed on by the mother. Every time a mother who is a carrier has a son, there is a 50% chance the son will be effected. Every time she has a daughter, there is a 50% chance the daughter will be a carrier, with the possibility of passing it on to her children.

Yes: The mother of the index kid may have some associated mild learning issues as would up to half her daughters. Any other male offspring have a 50% risk of getting the fragile X from her mother.