Same as nonFragile X. Mental retardation simply refers to overall cognitive delay. Fragile x is an identifiable genetic disorder that, in males, is associated with mild to moderate mr. Those with fragile x do have other unique features, but the mr really is not especially different from mr caused by other factors.
Do you mean severity. Boys with fragile x can have mild, moderate or severe intellectual disability. Most affected is speech/ language or trouble expressing themselves. Behavior problems include hyperactivity/impulsivity, tantrums, hand-flapping and poor eye contact. Some have autism. Research at the mind institute and elsewhere shows r-baclofen helps reduce symptoms, but this medicine is not on the market yet.
No. Females carry the fragile x gene. Males with fragile x will be affected.