how did fragile x syndrome get its name
Fragile X syndrome Fragile X syndrome is typically due to an expansion of the CGG triplet repeat within the Fragile X mental retardation 1 (FMR1) gene on the X chromosome.[1] This results in not enough fragile X mental retardation protein (FMRP), which is required for normal development of the connection between neurons.[1] Diagnosis is by genetic testing to determine the number of CGG repeats in the FMRI gene.[3] Normal is between 5 and 40 repeats, fragile X syndrome occurs with more than 200, and a premutation is said to be present when a middle number of repeats occur.[1] Testing for premutation carriers may allow for genetic counseling.[3]