May 2019 By

Fragile X Syndrome (FXS)

Fragile X Syndrome (FXS) is an X chromosome-linked dominant disorder caused by the amplification of a CGG repeat in the 5′ untranslated region of the fragile X mental retardation gene 1 (FMR1). It is the most common inherited cause of intellectual disability.


There is a prevalence of 1 in 3600 to 4000.[1]


Individuals have very high rates of anxiety disorders (over 80%), attention-deficit/hyperactivity disorder (over 50%), autism (30 to 35%), and mood instability and aggression.[2]

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