Myasthenia gravis in a child with sequelae of opsoclonus-myoclonus syndrome.

Immune-mediated myasthenia gravis occurred in a 13-month-old girl who had sequelae of an opsoclonus-myoclonus syndrome. She had an abnormal Raji cell assay along with elevated antiacetylcholine receptor and antithyroglobulin antibodies. No evidence of an associated malignancy was found with either condition. Clearly, the co-occurrence of two diseases within a single patient does not establish a common pathogenesis. Nevertheless, this is a provocative association and may point to an immunologically mediated process in the opsoclonus-myoclonus syndrome.