A family with myasthenia gravis with and without thymoma.

condition targeting the neuromuscular junction. Thymomas have been found in 10-15% of patients with acquired MG suggesting a paraneoplastic origin in these cases, and approximately onethird are designated as malignant with invasion of the capsule. Patients with thymoma are slightly older and more often have generalized symptoms compared to MG patients without thymoma.1 Although familial autoimmune MG has been reported occasionally, there is only one reported case of familial paraneoplastic MG from thymoma.2 Here we report a case of two siblings with paraneoplastic MG, where histological similitude was demonstrated by immunophenotyping. Their mother had earlier been diagnosed with MG, but had no evidence of thymoma. This is the first case reported of MG with thymoma and similar immunophenotyping in two or more family members, coexisting with MG without thymoma in the same family.