For patients who presented with non-clonal GlcSph-reactive Igs, the monoclonal Ig targeted an infectious pathogen (50% cases in MGUS, 28.6% in MM), or the target of the monoclonal Ig was not identified (14.7% in MGUS, 34.3% in MM), in a manner very similar to patients who do not have GlcSph-reactive Igs. The gene discussed is CUBN; the disease is Miyoshi myopathy.