LDB3 and cardiomyopathy: RBM20 is required for alternative splicing of several genes associated with cardiomyopathy including: titin (TTN), ryanodine receptor 2 (RYR2), calcium/calmodulin-dependent protein kinase II delta (CAM2D), and LIM domain binding 3 (LDB3)7, 8; furthermore, decreased levels of RBM20 in DCM leads to retention of commonly spliced exons.