Behavior therapy for a child with Lesch-Nyhan syndrome.

The behavioural symptoms in a 10-year-old boy with Lesch-Nyhan syndrome were effectively ameliorated by the behavior therapy techniques of systematic desensitization and extinction. Therapy was undertaken in a highly controlled environment. The hypothesis that the self-destructive behaviours in this syndrome were voluntary and maintained through continuous reinforcement was confirmed. Characteristic biting and other maladaptive behaviours were extinguished. Over a period of time it was possible to remove all the physical restraints previously used to prevent the boy injuring himself. During treatment his anxiety, associated with phobic reaction to being unrestrained, was reduced by nitrous oxide. At 1 1/2 years follow-up the boy continues to be symptom-free. He attends a special class at school and is learning to walk with crutches. It is emphasied that a trained and experienced therapist and a controlled environment are essential for the success of this form of behaviour therapy, and the dangers inherent in this method of treatment are discussed.