Is fragile x syndrome fatal?

No: Fragile X syndrome is a genetically inherited form of mental retardation.

Fragile X: per say is not fatal. Males are more likely to be accident prone and suffer seizures than females. The risk of seizures is 17-40% depending on the series studied. (Much higher than this in my series of patients) Ataxia, hypotonia and unpredictable responses to changes in environment can lead to accidents. But the disease itself is not fatal.

No: Life span is normal.

No : The syndrome almost always affects males but sometimes a female will express it. It causes significant mental impairment and has high rates of autism which can be incapacitating. With good health care lifespan appears normal.