Table 2.

Genetic mutations associated with dilated cardiomyopathy and cardiac arrhythmias

Gene	Function	Findings/Notes
Lamin A/C (LMNA)	Encodes structural proteins that provide stability to the nuclear envelope.	Mutations are involved in 8% of familial and 2% of sporadic DCM. They are associated with cardiac conduction disease.57,58 In one small study, LMNA mutation carriers, who had cardiac conduction disease requiring permanent pacemaker, had a high risk for ventricular arrhythmias and benefitted from ICD implantation.59
Phospholamban (PLN)	Transmembrane protein in the sarcoplasmic reticulum that plays a key role in calcium homeostasis.	In 403 mutation carriers, 20% of individuals had incident ventricular arrhythmias after a median follow-up of 42 months.60
Desmin (DES)	Intermediate filament protein that is expressed in skeletal, cardiac, and smooth muscle and helps to form the cytoskeletal network.	The majority of mutation carriers are reported to have cardiac conduction disease and/or arrhythmias.61 The most common abnormality reported was high degree atrioventricular block.
SCN5A	Cardiac sodium channel gene that is responsible for the fast depolarization of the myocardium and maintenance of impulse conduction in the heart.	Mutations found in 1.7% of DCM families.62 Two-thirds of these SCN5A mutations localized to the highly conserved, transmembrane segments suggesting a shared mechanism of disruption of the voltage-sensing mechanism of this channel and DCM.

DCM, dilated cardiomyopathy.