The CD138-positive PC of BM aspirates of MM patients #1, #2 and #3 bound R23IgG (78.2%, 66.3%, 95.9%, respectively, of the analyzed cell population) and H23 (78.3%, 59.2%, 93.2%, respectively, of the analyzed cell population) (Fig. 3 columns C and E). The gene discussed is SDC1; the disease is Miyoshi myopathy.