MYOM2 and Miyoshi myopathy: MM is consistently preceded by a premalignant phase called monoclonal gammopathy of undetermined significance (MGUS) and clinically defined by thresholds in serum M protein and clonal bone marrow plasma cell content with the absence of hypercalcemia, renal insufficiency, anemia, and bone lesions (known as CRAB features) or amyloidosis relating to the plasma cell proliferative disorder (Landgren et al., 2009; Rajkumar et al., 2014).