CRBN spliced variant has been associated with lenalidomide refractoriness, and unlike mutation or copy loss, CRBN exon10 splice isoform was observed in newly diagnosed MM (NDMM) patients at ~ 2.9% prevalence which increased to almost 30% in IMiD-resistant RRMM and was a prognostic marker for poor outcome in both disease setting [18]. This evidence concerns the gene CRBN and Miyoshi myopathy.