So far, DCM has been described in FKRP‐CDG, FKTN‐CDG, POMT1‐CDG, POMT2‐CDG, DOLK‐CDG, DPM3‐CDG, and PGM1‐CDG.19, 22 With the exception of PGM1‐CDG, these CDGs are associated with abnormal O‐mannosylation of αDG. This evidence concerns the gene DOLK and familial dilated cardiomyopathy.