常见的祖先特异性离子通道变异易患药物诱导的心律失常
Yuko Wada, Tao Yang1, Christian M Shaffer1
1Department of Medicine (Y.W., T.Y., C.M.S., L.L.D., A.M.G., G.E.D.), Vanderbilt University Medical Center, Nashville, TN.
Circulation
|January 7, 2022
概括
常见的SCN5A变异不会影响基线再极化,但在IKr被阻断时会增加QT延长的风险. 这凸显了药物反应研究中需要多样化的群体.
科学领域:
- 心血管遗传学
- 电生理学
- 药物基因组学
背景情况:
- SCN5A变体S1103Y和R1193Q与长QT综合征有关.
- 这些变异在特定的祖先群体中很常见, 质疑它们的基线节律失调潜力.
- 这些变异对心脏再极化的影响尚不清楚.
研究的目的:
- 研究SCN5A变异S1103Y对非洲裔美国人的QT间隔的影响.
- 确定S1103Y和R1193Q对心肌细胞动力潜力的持续时间和离子通道功能的影响.
- 了解这些变异在药物诱导的QT延长中的作用.
主要方法:
- 使用电子健康记录对S1103Y变异的非裔美国参与者的QT间隔进行分析.
- 使用诱导多能干细胞衍生的心肌细胞与自然存在的或基因组编辑的SCN5A变体.
- 评估了基线和IKr阻断剂dofetilide和INa-L后的潜在作用时间.
主要成果:
- 在临床队列中,S1103Y携带者与非携带者相比,QT间隔没有差异.
- 在心肌细胞中,S1103Y和R1193Q增加了晚期电流 (INa-L) 和几乎翻了一番的IKr.
- 具有S1103Y/ R1193Q变异的细胞对多费提利德的敏感性增加,延长了作用潜力的持续时间,并导致后分极化.
结论:
- 常见的SCN5A变体S1103Y和R1193Q尽管增加了INa-L,但并没有改变基线再极化.
- 在变异载体中增加的IKr可能保持正常的复极化,但在IKr封锁期间增加风险.
- 这些发现强调了在药物不良反应研究中包括多种人群的重要性.
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