To investigate the impact of LMNA mutations on the sumo1 sumoylation pathway, we examined sumoylation of lamin A/C and sumo1 localization in the presence of wild-type lamin A and C as well as DCM-associated p.Leu85Arg, p.Asp192Gly, and p.Gln353Lys lamin A and C mutants and EDMD-associated p.Arg386Lys and p.His222Pro lamin A and C mutants. The gene discussed is LMNA; the disease is familial dilated cardiomyopathy.