@article {336, title = {Multilevel analyses of SCN5A mutations in arrhythmogenic right ventricular dysplasia/cardiomyopathy suggest non-canonical mechanisms for disease pathogenesis.}, journal = {Cardiovasc Res}, volume = {113}, year = {2017}, month = {2017 01}, pages = {102-111}, abstract = {

AIMS: 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 Na1.5. We aimed to determine the prevalence and biophysical properties of mutations in SCN5A (the gene encoding Na1.5) in ARVD/C.

METHODS AND RESULTS: We performed whole-exome sequencing in six ARVD/C patients (33\% male, 38.2 {\textpm} 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{\textquoteright}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 Na1.5 (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 {\textpm} 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 {\textpm} 15 vs. 94 {\textpm} 14 ms, P < 0.01) and all SCN5A variant carriers had major structural abnormalities on cardiac imaging.

CONCLUSIONS: Almost 2\% of ARVD/C patients harbour rare SCN5A variants. For one of these variants, we demonstrated reduced sodium current, Na1.5 and N-Cadherin clusters at junctional sites. This suggests that Na1.5 is in a functional complex with adhesion molecules, and reveals potential non-canonical mechanisms by which Na1.5 dysfunction causes cardiomyopathy.

}, keywords = {Adult, Antigens, CD, Arrhythmogenic Right Ventricular Dysplasia, Cadherins, Cell Differentiation, CRISPR-Cas Systems, DNA Mutational Analysis, Electrocardiography, Exome, Female, Gene Editing, Gene Frequency, Genetic Predisposition to Disease, Genome-Wide Association Study, HEK293 Cells, Humans, Induced Pluripotent Stem Cells, Magnetic Resonance Imaging, Male, Membrane Potentials, Middle Aged, Multilevel Analysis, Mutation, Missense, Myocytes, Cardiac, NAV1.5 Voltage-Gated Sodium Channel, Netherlands, Phenotype, Sodium, Transfection, United States, Young Adult}, issn = {1755-3245}, doi = {10.1093/cvr/cvw234}, author = {Te Riele, Anneline S J M and Agullo-Pascual, Esperanza and James, Cynthia A and Leo-Macias, Alejandra and Cerrone, Marina and Zhang, Mingliang and Lin, Xianming and Lin, Bin and Sobreira, Nara L and Amat-Alarcon, Nuria and Marsman, Roos F and Murray, Brittney and Tichnell, Crystal and van der Heijden, Jeroen F and Dooijes, Dennis and van Veen, Toon A B and Tandri, Harikrishna and Fowler, Steven J and Hauer, Richard N W and Tomaselli, Gordon and van den Berg, Maarten P and Taylor, Matthew R G and Brun, Francesca and Sinagra, Gianfranco and Wilde, Arthur A M and Mestroni, Luisa and Bezzina, Connie R and Calkins, Hugh and Peter van Tintelen, J and Bu, Lei and Delmar, Mario and Judge, Daniel P} } @article {171, title = {Recurrent gain of function mutation in calcium channel CACNA1H causes early-onset hypertension with primary aldosteronism.}, journal = {Elife}, volume = {4}, year = {2015}, month = {2015 Apr 24}, pages = {e06315}, abstract = {

Many Mendelian traits are likely unrecognized owing to absence of traditional segregation patterns in families due to causation by de novo mutations, incomplete penetrance, and/or variable expressivity. Genome-level sequencing can overcome these complications. Extreme childhood phenotypes are promising candidates for new Mendelian traits. One example is early onset hypertension, a rare form of a global cause of morbidity and mortality. We performed exome sequencing of 40 unrelated subjects with hypertension due to primary aldosteronism by age 10. Five subjects (12.5\%) shared the identical, previously unidentified, heterozygous CACNA1H(M1549V) mutation. Two mutations were demonstrated to be de novo events, and all mutations occurred independently. CACNA1H encodes a voltage-gated calcium channel (CaV3.2) expressed in adrenal glomerulosa. CACNA1H(M1549V) showed drastically impaired channel inactivation and activation at more hyperpolarized potentials, producing increased intracellular Ca(2+), the signal for aldosterone production. This mutation explains disease pathogenesis and provides new insight into mechanisms mediating aldosterone production and hypertension.

}, keywords = {Adolescent, Adult, Age of Onset, Aldosterone, Amino Acid Sequence, Calcium, Calcium Channels, T-Type, Calcium Signaling, Child, Child, Preschool, Female, Gene Expression, Genotype, Heterozygote, Humans, Hyperaldosteronism, Hypertension, Infant, Male, Membrane Potentials, Middle Aged, Molecular Sequence Data, Mutation, Phenotype, Recurrence, Sequence Alignment, Zona Glomerulosa}, issn = {2050-084X}, doi = {10.7554/eLife.06315}, author = {Scholl, Ute I and St{\"o}lting, Gabriel and Nelson-Williams, Carol and Vichot, Alfred A and Choi, Murim and Loring, Erin and Prasad, Manju L and Goh, Gerald and Carling, Tobias and Juhlin, C Christofer and Quack, Ivo and Rump, Lars C and Thiel, Anne and Lande, Marc and Frazier, Britney G and Rasoulpour, Majid and Bowlin, David L and Sethna, Christine B and Trachtman, Howard and Fahlke, Christoph and Lifton, Richard P} }