Fragile-X is the most common form of inherited mental retardation in America with 1 in 1,500 males and 1 in 2,500 females showing symptoms of the disease.
Females are more often just carriers of the disease while males usually end up mentally retarded.
Symptoms Typical symptoms include anything from mental retardation to hyperactivity. Most have learning disablilties or average IQs. Karyotype of a patient's cell in metaphase. The top arrow points to the inactive normal X chromosome.