与心房颤动相关的HAND1等转录因子基因突变鉴定及功能研究

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. Genome-wide association studies (GWAS) and our own candidate gene study have highlighted the role of cardiac transcriptional factors (TFs) in AF. We identified HAND1 as a new AF-associated TF gene. According to our results from in silico analysis, we hypothesize that HAND1 and related TFs may involve in AF through regulation of atrial fibrosis. To test the hypothesis, we propose a delicated design used next-generation sequencing technology to sequence 20 carefully selected AF patients with a rapid progress of atrial fibrosis to idtentify founctional variants. The identified variants will be further validated in 300 unrelated patients with AF and 300 healthy controls. Subgroup analysis according to atrial fibrosis progress will also be performed to test the association between variants and atrial fibrosis. At last, a replicated TF variant with predicted pathogeneity will be explored in a transgenic mouse model to test pathogenity and its functional mechenism in the progress of AF and/or atrial fibrosis. Our results will improve the genetic understanding of AF, which will pave the way to personalized medication of AF and is also helpful in new antiarrhythmia drug development.

心房颤动是临床最常见的心律失常，严重危害人民健康。国外全基因组关联研究提示参与心脏和心血管发育的转录因子与房颤有关，国内缺乏系统性易感基因研究。我们前期发现HAND1是中国人孤立性房颤的新关联基因，并推测HAND1等转录因子可通过调控心肌纤维化或离子通道而影响房颤发生发展。本研究拟选取20例房颤伴高度心房纤维化的病例，借助二代高通量捕获测序技术全面筛查多个心脏发育转录因子基因的功能变异，深入探讨转录因子影响房颤发生发展的机制和它们之间的相互作用网络。对二代测序发现的候选变异在300：300的病例对照样本中验证其与房颤和心房纤维化的相关性。选择一个经过验证与房颤显著相关且推测有强致病性的转录因子突变构建点突变转基因小鼠模型，开展机体水平、组织水平和细胞水平的研究以确定其致房颤发生发展的机制。本研究结果对于未来开展房颤个体化医疗、降低房颤危害和新药开发具有重要意义。

本研究对57例早发房颤病例进行了全外显子组测序。分析119个候选基中的生物学预测有害的罕见有害变异，结果发现除SH3PXD2A基因rs202011870外，已知候选基因中的单个错义变异在早发房颤病人中并没有显著增多，与既往房颤外显子组研究结论一致。错义变异最多出现在TTN、MYH6和ZFHX3。Radical变异最多出现在CRELD2、TRDN和TTN。总体上，57例早发房颤病例中有50例（87.8%）有至少一个房颤候选基因中的预测有害罕见变异，平均每个样本有约2个这样的变异。全外显子组病人富集变异未发现明显与房颤有关的变异。本项目还完成了384:379的病例对照样本30个SNP位点关联分析，提示在中国汉族人样本中HAND1的SNP单体型与孤立性房颤可能相关。同时用对照组379例社区人群分析这些转录因子SNP位点与正常人群心电图参数的相关性。结果提示PITX2、HAND1的SNP位点与PR间期存在相关性。