Multilevel analyses of SCN5A mutations in arrhythmogenic right ventricular dysplasia/cardiomyopathy suggest non-canonical mechanisms for disease pathogenesis

• Published in: Cardiovascular research Vol. 113; no. 1; pp. 102 - 111
• Main Authors: te Riele, Anneline S.J.M., Agullo-Pascual, Esperanza, James, Cynthia A., Leo-Macias, Alejandra, Cerrone, Marina, Zhang, Mingliang, Lin, Xianming, Lin, Bin, Rothenberg, Eli, Sobreira, Nara L., Amat-Alarcon, Nuria, Marsman, Roos F., Murray, Brittney, Tichnell, Crystal, van der Heijden, Jeroen F., Dooijes, Dennis, van Veen, Toon A.B., Tandri, Harikrishna, Fowler, Steven J., Hauer, Richard N.W., Tomaselli, Gordon, van den Berg, Maarten P., Taylor, Matthew R.G., Brun, Francesca, Sinagra, Gianfranco, Wilde, Arthur A.M., Mestroni, Luisa, Bezzina, Connie R., Calkins, Hugh, Peter van Tintelen, J., Bu, Lei, Delmar, Mario, Judge, Daniel P.
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01.01.2017
• Series: Editor's Choice
• Subjects: Adult; Antigens, CD - metabolism; Arrhythmogenic Right Ventricular Dysplasia - diagnostic imaging; Arrhythmogenic Right Ventricular Dysplasia - genetics; Arrhythmogenic Right Ventricular Dysplasia - metabolism; Cadherins - metabolism; Cell Differentiation; CRISPR-Cas Systems; DNA Mutational Analysis; Electrocardiography; Exome; Female; Gene Editing - methods; Gene Frequency; Genetic Predisposition to Disease; Genome-Wide Association Study; HEK293 Cells; Humans; Induced Pluripotent Stem Cells - metabolism; Magnetic Resonance Imaging; Male; Membrane Potentials; Middle Aged; Multilevel Analysis; Mutation, Missense; Myocytes, Cardiac - metabolism; NAV1.5 Voltage-Gated Sodium Channel - genetics; NAV1.5 Voltage-Gated Sodium Channel - metabolism; Netherlands; Original; Phenotype; Sodium - metabolism; Transfection; United States; Young Adult; Genetics; SCN5A; Arrhythmogenic right ventricular cardiomyopathy; Ion channel electrophysiology; Cardiomyopathy
• ISSN: 0008-6363; 1755-3245; 1755-3245
• DOI: 10.1093/cvr/cvw234

Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy (ARVD/C) is often associated with desmosomal mutations. Recent studies suggest an interaction between the desmosome and sodium channel protein Na 1.5. We aimed to determine the prevalence and biophysical properties of mutations in SCN5A (the gene encoding Na 1.5) in ARVD/C. We performed whole-exome sequencing in six ARVD/C patients (33% male, 38.2 ± 12.1 years) without a desmosomal mutation. We found a rare missense variant (p.Arg1898His; R1898H) in SCN5A in one patient. We generated induced pluripotent stem cell-derived cardiomyocytes (hIPSC-CMs) from the patient's peripheral blood mononuclear cells. The variant was then corrected (R1898R) using Clustered Regularly Interspaced Short Palindromic Repeats/Cas9 technology, allowing us to study the impact of the R1898H substitution in the same cellular background. Whole-cell patch clamping revealed a 36% reduction in peak sodium current (P = 0.002); super-resolution fluorescence microscopy showed reduced abundance of Na 1.5 (P = 0.005) and N-Cadherin (P = 0.026) clusters at the intercalated disc. Subsequently, we sequenced SCN5A in an additional 281 ARVD/C patients (60% male, 34.8 ± 13.7 years, 52% desmosomal mutation-carriers). Five (1.8%) subjects harboured a putatively pathogenic SCN5A variant (p.Tyr416Cys, p.Leu729del, p.Arg1623Ter, p.Ser1787Asn, and p.Val2016Met). SCN5A variants were associated with prolonged QRS duration (119 ± 15 vs. 94 ± 14 ms, P < 0.01) and all SCN5A variant carriers had major structural abnormalities on cardiac imaging. Almost 2% of ARVD/C patients harbour rare SCN5A variants. For one of these variants, we demonstrated reduced sodium current, Na 1.5 and N-Cadherin clusters at junctional sites. This suggests that Na 1.5 is in a functional complex with adhesion molecules, and reveals potential non-canonical mechanisms by which Na 1.5 dysfunction causes cardiomyopathy.