布氏综合征（BrS）是一种可以导致突发性心脏死亡（SCD）的心脏离子通道病。SCN5A基因是与BrS最常关联的基因，但基因型-表型相关性尚不完全匹配。某个特定的SCN5A变异体的临床表型可从无症状至SCD。本研究利用来自一例SCN5A突变阳性（D356Y）BrS家族的诱导多能干细胞衍生心肌细胞（iPSC-CMs），与严重患者、无症状突变体（AMCs）和健康对照进行比较，以研究这种变异。使用非整合性Sendai病毒从皮肤成纤维细胞中生成了26株iPSC。通过基于单层分化的方案将产生的iPSC分化为心肌细胞。与对照组相比，D356Y iPSC-CMs表现出增加的心跳间期可变性、较慢的去极化、心脏心律失常、Na+通道功能缺陷和不规则的Ca2+信号传递。重要的是，AMC iPSC-CMs的表型严重程度比患者iPSC-CMs的表型严重度更轻，而服用氟卡尼胺后这一现象更加明显。有趣的是，与对照和AMC iPSC-CMs相比，患者iPSC-CMs明显减少了Ca2+电流。通过应用CRISPR/Cas9介导的基因组编辑来纠正患者iPSC-CMs中的D356Y，有效恢复了心律失常表型并恢复了Na+和Ca2+电流。此外，使用已建立的BrS iPSC-CM模型进行药物筛选表明，奎尼丁和索他洛以个体因素为依赖的方式具有抗心律失常效应。临床上，静脉和口服钙在中期随访中部分减少了患者的恶性心律失常事件。患者特异性和基因组编辑的iPSC-CMs可以再现BrS的不同表型严重程度。我们的研究结果表明，在BrS AMCs中，Ca2+电流的保留可能是一种抗心律失常的代偿机制。 中国国家重点研发计划（2017YFA0103700）、中国国家自然科学基金（81922006、81870175）、浙江省自然科学基金（LD21H020001、LR15H020001）、中国国家自然科学基金（81970269）、浙江省重点研发计划（2019C03022）和浙江省自然科学基金（LY16H020002）资助。© 2023作者。由Elsevier B.V.出版。保留所有权利。

Brugada syndrome (BrS) is a cardiac channelopathy that can result in sudden cardiac death (SCD). SCN5A is the most frequent gene linked to BrS, but the genotype-phenotype correlations are not completely matched. Clinical phenotypes of a particular SCN5A variant may range from asymptomatic to SCD. Here, we used comparison of induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) derived from a SCN5A mutation-positive (D356Y) BrS family with severely affected proband, asymptomatic mutation carriers (AMCs) and healthy controls to investigate this variation.26 iPSC lines were generated from skin fibroblasts using nonintegrated Sendai virus. The generated iPSCs were differentiated into cardiomyocytes using a monolayer-based differentiation protocol.D356Y iPSC-CMs exhibited increased beat interval variability, slower depolarization, cardiac arrhythmias, defects of Na+ channel function and irregular Ca2+ signaling, when compared to controls. Importantly, the phenotype severity observed in AMC iPSC-CMs was milder than that of proband iPSC-CMs, an observation exacerbated by flecainide. Interestingly, the iPSC-CMs of the proband exhibited markedly decreased Ca2+ currents in comparison with control and AMC iPSC-CMs. CRISPR/Cas9-mediated genome editing to correct D356Y in proband iPSC-CMs effectively rescued the arrhythmic phenotype and restored Na+ and Ca2+ currents. Moreover, drug screening using established BrS iPSC-CM models demonstrated that quinidine and sotalol possessed antiarrhythmic effects in an individual-dependent manner. Clinically, venous and oral administration of calcium partially reduced the malignant arrhythmic events of the proband in mid-term follow-up.Patient-specific and genome-edited iPSC-CMs can recapitulate the varying phenotypic severity of BrS. Our findings suggest that preservation of the Ca2+ currents might be a compensatory mechanism to resist arrhythmogenesis in BrS AMCs.National Key R&D Program of China (2017YFA0103700), National Natural Science Foundation of China (81922006, 81870175), Natural Science Foundation of Zhejiang Province (LD21H020001, LR15H020001), National Natural Science Foundation of China (81970269), Key Research and Development Program of Zhejiang Province (2019C03022) and Natural Science Foundation of Zhejiang Province (LY16H020002).Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.