Genetic Testing For Fmr1 Variants (Including Fragile X Syndrome)

Fragile X syndrome (FXS) is the most common inherited form of mental disability and a known genetic cause of autism. The diagnosis is made with a genetic test that determines the number of CGG repeats in the fragile X mental retardation 1 gene, (FMR1). FMR1 variant testing has been investigated in a variety of clinical settings, including the evaluation of individuals with a personal or family history of intellectual disability, developmental delay, or autism spectrum disorder and in reproductive decision-making in individuals with known FMR1 variants or positive cytogenetic fragile X testing. FMR1 variants also cause premature ovarian failure and a neurologic disease called fragile X-associated ataxia or tremor syndrome.