Behaviors reflect obsessive-compulsive tendencies, hyperactivity, attention deficit, and autism. Fragile X syndrome is the second most common chromosomal cause of mental retardation. The severity of cognitive, language and behavioral outcomes may be related to the actual number of CCG amino acid repeats at the affected site on the lower end of the X chromosome. Behaviors such as crawling under a table or tantrums are efforts to escape the sensory overload they perceive. These children can be hypersensitive to lighting, noise, food and clothing textures, odors, touch, and sudden changes in routine.
Eye contact is more aversive to a child with fragile X syndrome than to autistic students.
Interventions include not forcing eye contact, allowing student to wear sunglasses, or asking educational diagnostician to wear sunglasses when administering appraisal tests. Students with fragile X syndrome already tend to do poorly on IQ tests because it is a change in routine, but they perform better on achievement tests which are related to classroom routines.