Mental retardation. Mental retardation, autistic behavior, large testicles, long face, and large ears. Mainly seen in boys (but inherited from mother). Diagnosed by a blood test. There is an expanded dna segment called a trinucleotide repeat. This expanded dna segment is located on the x chromosome.
Male dominated. The fragile x is named for a non staining region on the long arm of an x containing useless genetic material that results in mental impairment & physical changes(if you only have 1 x:males).The females usually show few if any features due to protection by a normal x, but not always & have a 50% chance of passing the fragile x to any offspring. This is a male dominated form of mental impairment.
Abnormal chromosome. Fragile X is an abnormality on the X chromosome which is associated with learning problems, developmental delay and behavioral abnormalities.