Newer investigations indicate that a subgroup of approximately 10-15% of inherited DCM cases has a higher incidence of severe heart rhythm disorders and thereby worsened prognosis. In a considerable part of these families the disease is caused by a genetic mutation in a specific gene that codes for a nuclear membrane protein and that mutation is labelled lamin A/C. The recognition of the linkage between the genotype and the clinical presentation of the disease (phenotype), has formed the foundation of clinical algorithms and made it possible to improve the individualised risk stratification and the choice of treatment.