With a known familial history of mesothelioma and melanoma, our patient underwent genetic testing which revealed a mutation in BAP1, affirming the strong association with the development of MPM. Young patients who develop malignant mesothelioma without risk factors for MM should have germline testing for BAP1. This case report is unique and highlights a familial variant of mesothelioma, even rare with peritoneal mesothelioma in our patient. Here, BAP1 is linked to Miyoshi myopathy.