To estimate the frequency of DIS3 mutations in different phases of plasma cell dyscrasia, 164 cases (including 130 MM, 24 pPCL and 10 sPCL patients) and 20 human myeloma cell lines (HMCLs) were subjected to deep sequencing of the two functional domains of the gene, namely PIN and RNB domains. The gene discussed is DIS3; the disease is Miyoshi myopathy.