GSTM1 and Miyoshi myopathy: Clinical data were available on 75 MM patients (57 newly diagnosed and 18 relapsed disease) as follow: median age 66 years (range 38-87); monoclonal component IgG 42 cases (56%), IgA 20 cases (26.7%), 12 light chain myelomas (16%) and 1 non-secreting myeloma (1.3%); LDH serum levels higher than normal, 13 patients (17.3%); serum levels of β2-microglobulin higher than 3.5 mg/dL and 5.5 mg/dL 24 (32%) and 17 (22.6%) cases, respectively; Hb <10 gr/dL 24 patients (32%); osteolytic lesions 45 cases (60%); ISS stage I, II, III in 31 (41.4%), 27 (36%) e 17 (22.6%) patients, respectively.