Dilated Cardiomyopathy
Gene: SCN5A
(Likely) pathogenic gain of function variants in SCN5A are associated with Multifocal Ectopic Purkinje-related Premature Contractions (MEPPC) syndrome, characterised by a high burden of premature ventricular contractions (PVCs) originating from multiple foci along the fascicular Purkinje system, and featuring a narrow QRS complex.
MEPPC syndrome was initially described in three Dutch families by Laurent et al. in 2012 (PMID: 22766342). As summarised in a systematic review of n=115 patients affected with MEPPC syndrome by Basile et al., 2025 (PMID: 41159261), MEPPC is typically diagnosed in young patients, with no reported cases with an age of onset >50 years. Common clinical manifestations include palpitations, dyspnea and syncope. Several reported cases are affected with, or have a family history of, dilated cardiomyopathy, sudden death, and/or other hereditary cardiovascular disorders.
The high degree of expressive variability of SCN5A (likely) pathogenic variants and/or simultaneous gain- and loss- of function conferred by these variants, have led to the recognition of "overlap syndrome" - wherein MEPPC syndrome may be associated with other hereditary cardiovascular disorders including long QT syndrome, Brugada syndrome, cardiac conduction disorders and/or dilated cardiomyopathy (PMID: 41159261).Created: 18 Jun 2026, 12:01 p.m. | Last Modified: 18 Jun 2026, 12:01 p.m.
Panel Version: 2.0
Mode of inheritance
MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted
Phenotypes
Multifocal ectopic Purkinje-related premature contractions (MEPPC) syndrome; SCN5A-related cardiac rhythm disorder MONDO:1010181
Publications
DEFINITIVE by ClinGen:
SCN5A was first reported in relation to autosomal dominant dilated cardiomyopathy (DCM) in 2005 (Olson et al., 2005, PMID: 15671429). Human genetic evidence supporting this gene-disease relationship includes case-level data and segregation data. Numerous variants (missense, frameshift, nonsense) have been reported in humans with isolated DCM (Olson et al., 2005, PMID: 15671429; Ge et al., 2008, PMID: 19808398; McNair et al., 2011, PMID: 21596231; Morales et al., 2011, PMID: 20458009; Grosselin-Badaroudine et al., 2012, PMID: 22675453; Laurent et al., 2012, PMID: 22766342; Mann et al., 2012, PMID: 22999724; Zakrzewska-Koperska et al., 2018, PMID: 29871609; Calloe et al., 2018, PMID: 29506689; Gigli et al., 2019, PMID: 31514951; Doisne et al., 2020, PMID: 31930659). This gene-disease association is supported by mouse models, a human iPS cell culture model, and expression studies. SCN5A mRNA levels were markedly decreased in heart tissues obtained from DCM patients (Kepenek et al., 2019, PMID: 31520233). The myosin heavy chain-Snail transgenic mice displayed a DCM phenotype with conduction block and marked reduction of SCN5A expression (Hesse, et al., 2007, PMID: 17512504). Heterozygous and homozygous knock-in mouse models harboring SCN5A p.D1275N displayed a DCM phenotype including intraventricular conduction block with marked reduction of cardiac sodium currents (Watanabe et al., 2011, PMID: 21824921). Furthermore, patient-derived human iPS cell-induced cardiomyocytes carrying SCN5A p.R219H showed reduced contraction, prolonged action potential duration, early afterdepolarization, and H+-leak currents (Moreau et al., 2018, PMID: 30218094).Created: 26 Mar 2021, 8:14 p.m.
Mode of inheritance
MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted
Phenotypes
Cardiomyopathy, dilated, 1E, MIM# 601154
Publications
Phenotypes for gene: SCN5A were changed from Cardiomyopathy, dilated, 1E, MIM# 601154 to Cardiomyopathy, dilated, 1E, MIM# 601154; Multifocal ectopic Purkinje-related premature contractions (MEPPC) syndrome; SCN5A-related cardiac rhythm disorder MONDO:1010181
Publications for gene: SCN5A were set to 15671429; 15671429; 19808398; 21596231; 20458009; 22675453; 22766342; 22999724; 29871609; 29506689; 31514951; 31930659; 31520233; 17512504; 21824921; 30218094
Gene: scn5a has been classified as Green List (High Evidence).
Phenotypes for gene: SCN5A were changed from to Cardiomyopathy, dilated, 1E, MIM# 601154
Publications for gene: SCN5A were set to
Mode of inheritance for gene: SCN5A was changed from Unknown to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted
gene: SCN5A was added gene: SCN5A was added to Dilated cardiomyopathy_VCGS. Sources: Expert Review Green,Victorian Clinical Genetics Services Mode of inheritance for gene: SCN5A was set to Unknown