Psychiatric disorders, myoclonus dystonia, and the epsilon‐sarcoglycan gene: A systematic review

BACKGROUND: Mutations in the maternally imprinted epsilon-sarcoglycan gene occur in 30%-50% of myoclonus-dystonia cases. Psychiatric symptoms, particularly obsessive-compulsive disorder, have been described in some patients. METHODS: We systematically reviewed 22 reports of psychiatric symptoms in myoclonus-dystonia, dividing individuals according to clinical and mutation status. RESULTS: Clinically manifesting mutation carriers demonstrated an excess of psychiatric disorders compared with nonmutation carriers (P < .001). No differences were seen between non-motor-manifesting carriers and nonmutation carriers with the exception of alcohol excess/dependence, higher in non-motor-manifesting carriers. CONCLUSIONS: The results confirm the association of epsilon-sarcoglycan gene mutations with psychiatric disease and suggest a possible separation of the motor and psychiatric effects.