We suppose that the DSP_V508fs variant is the primary disease-causing mutant since the DSP gene has been demonstrated to be associated with DCM (OMIM: 615821) and biventricular arrhythmogenic cardiomyopathy (OMIM: 607450) and that AKAP9 may be a modifying gene causing severe ventricular tachyarrhythmias, such as those occurring in the patient identified as 76DCM. The gene discussed is AKAP9; the disease is familial dilated cardiomyopathy.