Challenging behaviour in a patient with schizophrenia and a 1q21.1 duplication.

We report the case of a 42-year-old man with a 22-year history of schizophrenia, necessitating frequent detentions under the Mental Health Act for relapses in his mental state and challenging behaviour which has also brought him into contact with the law. His illness has proven resistant to treatment with conventional strategies and he developed serious priapism with clozapine. His challenging behaviour, some of which is not felt to be associated with schizophrenia, complicates any discharge planning from his current detention. Based on a history of childhood cardiac disease, and mildly atypical facies, a genetic screen was requested which showed a 1q21.1 duplication, likely causal in his schizophrenic illness. A review of proteins coded by the locus of the duplication did not reveal any specific targets for pharmacotherapy. 2014 BMJ Publishing Group Ltd.