Self-injurious behavior and fragile X syndrome: findings from the national fragile X survey.

Van der Molen et al. (2010) mined the U.S. National Fragile X Survey. They asked parents about self-injury and other problems. The team compared boys with fragile X who hit or bit themselves to boys who did not.

No new treatment was tested. The goal was to map how common self-injury is and what else travels with it.

Boys with fragile X plus self-injury almost always carry extra baggage. Parents reported more sensory seeking, hyperactivity, aggression, autism traits, and anxiety than in boys without self-injury.

Girls showed a different pattern, but far fewer girls were in the survey.

Misak et al. (2011) and Machalicek et al. (2014) later ran small lab tests and found escape and tangible items—not attention—keep the behavior going. The survey data line up: kids who are sensory-seeking and hyperactive may be trying to escape overload or gain toys.

Rooker et al. (2020) show the same functions can predict injury severity. Together the papers say: first check if the child is trying to get out of something or get something tangible.

Scott et al. (2018) add another layer. They show boys with fragile X plus autism have weaker daily-living skills. J et al.’s sample likely overlaps, hinting that self-injury, autism, and skill delays cluster in the same high-risk boys.

When you see self-injury in a boy with fragile X, screen for sensory issues, hyperactivity, and autism right away. Build plans that teach escape requests and offer matched sensory input before problem behavior starts. Target daily-living skills too—success with tasks may cut the need to escape them.