Extramedullary myeloma whole genome sequencing reveals novel mutations in Cereblon, proteasome subunit G2 and the glucocorticoid receptor in multi drug resistant disease

摘要

Extramedullary disease (EMD) in Multiple Myeloma (MM) is characterized by the detection of monoclonal plasma cells outside the bone marrow niche, and is frequently associated with poor prognosis. Here we describe novel genomic events leading to drug refractory disease in a heavily pretreated 37-year-old IgG-kappa MM patient presenting with progressive, multi-drug refractory EMD. For the first time we report an acquired truncating mutation of Cereblon (CRBN) as well as point mutations in proteasome subunit G2 and the glucocorticoid receptor as an explanation for drug resistance. Initial myeloma treatment for the patient occurred over multiple years and included the immunomodulatory drugs (IMiDs) thalidomide and lenalidomide, the proteasome inhibitor bortezomib, cor-ticosteroids, radiation, one autologous and two allogeneic transplantations.