In our study, LC only isotype was also demonstrated to be the most common M-protein isotype for the whole t(11;14) cohort (46.2%), meanwhile, we found that the LC only isotype showed closely associated with cardiac amyloidosis (cardiac amyloidosis vs. no cardiac amyloidosis: 80.0% vs. 32.4%, p = 0.002). This evidence concerns the gene MYOM2 and cardiac amyloidosis.