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Fragile X Syndrome

Fragile X Syndrome Symptoms and Causes

Fragile X syndrome is a trinucleotide repeat disease that causes mental retardation from mild to severe, in both males and females. Autistic behavior, frequent tantrums and hyperactivity are commonly seen with fragile X syndrome. The gene that causes fragile X syndrome, called FMR1, is located on the X chromosome. Females are usually not as severely affected as males because females have a normal X chromosome in addition to the X with the mutation.