中国人遗传性长QT综合征KCNQ1和KCNH2基因新突变

目的 :遗传性长QT综合征 (LQTS)是一种常染色体遗传性心脏病。特征性表现为心电图上QTc延长及尖端扭转性室性心动过速 (TdP)导致的晕厥和猝死。近年来随着分子遗传学的发展已明确遗传性LQTS是由于编码离子通道的基因突变造成的 ,包括编码钠离子通道的基因SCN5A和编码钾离子通道亚单位的基因KCNQ1,KC NH2 ,KCNE1,KCNE2 ,和KCNJ2。目前 ,中国人LQTS基因突变的报道较少 ,本研究目的是找到中国LQTS基因突变。方法 :应用聚合酶链反应和测序分析 ,对来自中国 14个省、市、自治区的 31个遗传性LQTS家系筛查了最常见的 2个LQTS致病基因KCNQ1和KCNH2。结果 :发现了 2个KCNQ1新突变 :S5跨膜片段的S2 77L和孔区的G30 6V;3个KCNH2新突变 :跨膜片段S1的L4 13P、跨膜片段S5的L5 5 9H和发生于跨膜片段S3的L5 2 0V。KCNH2L4 13P和L5 5 9H突变患者的ECGT波为双峰 ;KCNQ1S2 77L和G30 6V突变患者的ECGT波高尖。结论 :本研究发现的突变点丰富了LQTS离子通道突变的基因库资料。本研究的中国LQTS患者的突变率KCNQ1(6 .5 % )和KCNH2(10 % )

KCNQ1和KCNH2基因与家族性阵发性房室交界折返性心动过速的关系

目的 :分析离子通道基因 KCNQ1和 KCNH2与家族性阵发性房室交界折返性心动过速 (FPAVJRT)的关系 ,以探讨 FPAVJRT发生的分子遗传机制。方法 :在一个 FPAVJRT大家系中 ,采用 PCR直接测序技术 ,对 KC-NQ1和 KCNH2基因的所有外显子和附近的部分内含子进行序列测定。结果 :KCNQ1基因存在 5种突变 ,其中 2个位于外显子区域 ,但均为同义突变 ,另外 3个位于内含子区域 ;而 KCNH2基因存在 3种突变 ,但均位于内含子区域。结论 :在该 FPAVJRT家系中 ,KCNQ1和 KCNH2基因存在 8种突变 ,但均为非致病突变 ,提示 KCNQ1和 KCNH2基因以外的基因可能才是 FPAVJRT致病基因。

KCNQ1和KCNH2基因与先天性长QT综合征的关系

目的 分析离子通道基因KCNQ1和KCNH2与先天性长QT综合征 (long QTsyndrome ,LQTS)的关系 ,以探讨LQTS发生的分子遗传机制。方法 在一个LQTS(JervellLange -Nielsen综合征型 )大家系中 ,采用PCR -直接测序技术 ,对KCNQ1和KCNH2基因的所有外显子和附近的部分内含子进行序列测定。结果 KCNQ1基因存在两种突变 ,其中一个位于外显子区域 ,但为同义突变 ,另外一个位于内含子区域 ;KCNH2基因也存在两种突变 ,均位于内含子区域。这四种单核苷酸有多态性 ,与现有报道不同。结论 在该LQTS家系中 ,KCNQ1和KCNH2基因存在四种突变 ,但均为非致病突变 ,提示KCNQ1和KCNH2基因以外的基因可能才是LQTS致病基因。KCNQ1基因和KCNH2基因存在新的单核苷酸多态性。

KCNQ1和KCNH2基因与家族性阵发性房室交界折返性心动过速的关系

目的:分析离子通道基因KCNQ1和KCNH2与家族性阵发性房室交界折返性心动过速(FPAVJRT)的关系,以探讨FPAVJRT发生的分子遗传机制。方法:在一个FPAVJRT大家系中,采用PCR直接测序技术,对KCNQ1和KCNH2基因的所有外显子和附近的部分内含子进行序列测定。 结果:KCNQ1基因存在5种突变,其中2个位于外显子区域,但均为同义突变,另外3个位于内含子区域;KCNH2基因存在3种突变,但均位于内含子区域。 结论:在该FPAVJRT家系中,KCNQ1和KCNH2基因存在8种突变,但均为非致病突变,提示KCNQ1和KCNH2基因以外的基因可能才是FPAVJRT致病基因。

KCNH2基因c.358G>T突变导致家族性长QT综合征的实验研究

目的寻找并验证导致家族性长QT综合征(LQTS)的遗传因素。方法从临床LQTS病例中筛选出具有家系背景的病患,收集相关临床资料,提取先证者血标本全基因组DNA后进行基因检测,并对先证者直系及旁系亲属血样进行测序验证,同时设计了相关细胞实验。首先构建KCNH2-G120W点突变质粒,然后将突变质粒及野生KCNH2通过表达质粒分别转染细胞,通过膜片钳检测不同组全细胞膜电位。结果通过高通量测序找到了KCNH2基因c.358G>T这一突变位点,同时证实了在家系中该位点杂合突变与LQTS密切相关。实验结果显示KCNH2-G120W突变质粒组的尾电流显著下降,提示突变体不能正常地运送至细胞膜表面而导致电流下降。结论通过临床家系研究和细胞水平实验发现了导致家族性LQTS的新突变位点,为LQTS的筛查、检测乃至临床治疗提供了新的路径。

KCNQ1和KCNH2基因与家族性猝死的关系

目的 分析离子通道基因KCNQ1和KCNH2与家族性猝死 (familialsuddendeath ,FSD)的关系 ,以探讨其分子遗传机制。方法 在 1个FSD大家系中 ,利用PCR直接测序技术 ,对KCNQ1和KCNH2基因的所有外显子和附近的部分内含子进行序列测定。结果 KCNQ1基因存在 4种突变 ,其中 3个位于外显子区域 ,但均为同义突变 ,另外 1个位于内含子区域 ;而KCNH2基因未发现突变。结论 在该FSD家系中 ,KCNQ1基因存在 4种突变 ,但均为非致病突变 ,KCNH2基因无突变发生 ;KCNQ1和KCNH2基因以外的基因可能才是FSD致病基因。

1例KCNH2基因突变致长QT综合征病例分析

目的:探讨长QT综合征的致病基因及其基因突变与临床表型的相关性。方法:回顾分析1例可疑长QT综合征患儿的临床资料,并利用全外显子测序(WES)筛查可能导致长QT综合征的突变。利用致病性评分、遗传模式及Sanger测序验证突变。结果:基因检测结果提示患儿存在KCNH2基因c.3100_3109delGACACGGAGC杂合突变,各类预测软件提示该突变是有害突变。Alphafold分析提示该突变会导致蛋白质截短。结论:KCNH2基因c.3100_3109delGACACGGAGC杂合突变是本例患儿的致病突变,并且该突变可能影响了KCNH2蛋白的稳定性。

Discovery of Digenic Mutation, KCNH2 c.1898A > C and JUP c.916dupA, in a Chinese Family with Long QT Syndrome via Whole-Exome Sequencing

Long QT syndrome(LQTS),which is caused by an ion channel–related gene mutation,is a malignant heart disease with a clinical course of a high incidence of ventricular fi brillation and sudden cardiac death in the young.Mutations in KCNH2(which encodes potassium voltage-gated channel subfamily H member 2)are responsible for LQTS in many patients.Here we report the novel mutation c.1898A>C in KCNH2 in a Chinese family with LQTS through whole-exome sequencing.The c.916dupA mutation in JUP(which encodes junction plakoglobin)is also discovered.Mutations in JUP were found to be associated with arrhythmogenic right ventricular cardiomyopathy.The double mutation in the proband may help explain his severe clinical manifestations,such as sudden cardiac death at an early age.Sequencing for the proband’s family members revealed that the KCNH2 mutation descends from his paternal line,while the mutation in JUP came from his maternal line.The data provided in this study may help expand the spectrum of LQTS-related KCNH2 mutations and add support to the genetic diagnosis and counseling of families affected by malignant arrhythmias.

KCNH2基因变异致2型长QT综合征一个家系的临床及遗传学分析

目的探讨1个2型长QT综合征(LQTS)家系的临床与遗传学病因。方法选取2019年8月23日就诊于阜外华中心血管病医院的1个2型LQTS家系为研究对象。采集先证者及其父母的外周血样并提取基因组DNA,对先证者进行全外显子组测序(WES),通过功能注释与PPI分析筛选候选变异。针对候选变异进行Sanger测序验证与致病性分析。本研究通过阜外华中心血管病医院医学伦理委员会的审查(伦理号:2019-15)。结果WES检测结果显示先证者携带KCNH2基因c.1478A>G(p.Tyr493Cys)错义变异,经Sanger测序验证该变异遗传自其父亲。根据美国医学遗传学与基因组学学会(ACMG)相关指南,该变异被判定为可能致病性(PM2_supporting+PM5+PP3+PP4)。结论KCNH2基因c.1478A>G(p.Tyr493Cys)变异可能是上述家系患2型LQTS的遗传学病因。

Potassium voltage-gated channel subfamily H member 2(KCNH2)is a promising target for incretin secretagogue therapies

Derived from enteroendocrine cells(EECs),glucagon-like peptide-1(GLP-1)and glucose-dependent insulinotropic peptide(GIP)are pivotal incretin hormones crucial for blood glucose regulation.Medications of GLP-1 analogs and GLP-1 receptor activators are extensively used in the treatment of type 2 diabetes(T2D)and obesity.However,there are currently no agents to stimulate endogenous incretin secretion.Here,we find the pivotal role of KCNH2 potassium channels in the regulation of incretin secretion.Co-localization of KCNH2 with incretin-secreting EECs in the intestinal epithelium of rodents highlights its significance.Gut epithelial cell-specific KCNH2 knockout in mice improves glucose tolerance and increases oral glucose-triggered GLP-1 and GIP secretion,particularly GIP.Furthermore,KCNH2-deficient primary intestinal epithelial cells exhibit heightened incretin,especially GIP secretion upon nutrient stimulation.Mechanistically,KCNH2 knockdown in EECs leads to reduced K+currents,prolonged action potential duration,and elevated intracellular calcium levels.Finally,we found that dofetilide,a KCNH2-specific inhibitor,could promote incretin secretion in enteroendocrine STC-1 cells in vitro and in hyperglycemic mice in vivo.These findings elucidate,for the first time,the mechanism and application of KCNH2 in regulating incretin secretion by EECs.Given the therapeutic promise of GLP-1 and GIP in diabetes and obesity management,this study advances our understanding of incretin regulation,paving the way for potential incretin secretagogue therapies in the treatment of diabetes and obesity.

一个先天性长QT综合征家系KCNH2基因新突变的确定及其编码蛋白的二级结构预测

目的确定一个先天性长QT综合征家系的基因突变位点，并对突变所引起的编码蛋白的结构改变进行预测。方法应用聚合酶链反应和直接测序分析先证者，找到突变位点后合成位点特异性引物，应用多重聚合酶链反应对长QT家系成员进行筛查；利用网络分析软件对突变所引起的编码蛋白结构进行预测。结果发现了1个KCNH2基因新错义突变，即跨膜片段s2的F463L突变（GenBank接受序列号EU218526）；突变没有引起预测跨膜区的改变，但编码蛋白的疏水性及二级结构，突变基因最小自由能二级结构都发生了变化。结论作者所发现的突变点丰富了长QT综合征离子通道突变的基因库资料，用软件分析基因突变可能引起编码蛋白二级结构的改变有利于理解引起长QT综合征的结构基础。

Mutation analysis of potassium channel genes KCNQ1 and KCNH2 in patients with long QT syndrome

Objective To determine mutations of two common potassium channel subunit genes KCNQ1, KCNH2 causing long QT syndrome (LQTS) in the Chinese.Methods Thirty-one Chinese LQTS pedigrees were characterized for mutations in the two LQTS genes, KCNQ1 and KCNH2, by sequencing.Results Two novel KCNQ1 mutations, S277L in the S5 domain and G306V in the channel pore, and two novel KCNH2 mutations, L413P in the transmembrane domain S1 and L559H in the transmembrane domain S5 were identified. The triggering factors for cardiac events developed in these mutation carriers included physical exercise and excitation. Mutation L413P in KCNH2 was associated with the notched T wave on ECGs. Mutation L559H in KCNH2 was associated with the typical bifid T wave on ECGs. Mutation S277L in KCNQ1 was associated with a high-amplitude T wave and G306V was associated with a low-amplitude T wave. Two likely polymorphisms, IVS11 +18C >T in KCNQ1 and L520V in KCNH2 were also identified in two LQTS patients.Conclusions The mutation rates for both KCNQ1 (6.4%) and KCNH2 (6.4%) are lower in the Chinese population than those from North America or Europe.

KCNH2 regulates the growth and metastasis of pancreatic cancer

Objective:Due to the characteristics of insidious onset and early metastasis of pancreatic cancer(PC),patients are often diag-nosed at an advanced stage and often delayed in completing surgical resection timely,resulting in poor prognosis.Therefore,this study aims to explore the expression of potassium voltage-gated channel subfamily H member 2(KCNH2)in PC and its relation-ship with clinicopathological parameters and the related mechanisms.Methods:GEPIA database and immunohistochemical staining were used to analyze the difference in KCNH2 expression be-tween PC and adjacent tissue in RNA and protein levels.Chi-squared test was used to evaluate the relationship between KCNH2 expression and clinicopathological features.The Cox regression model was used for multivariate analysis and univariate analysis.Histological diagnosis was performed according to World Health Organization(WHO)criteria to evaluate the relationship between KCNH2 expression and clinicopathological features.Results:KCNH2 expression was upregulated in PC compared with normal pancreatic tissue.In addition,the knockdown of KCNH2 inhibits PC cell proliferation,migration,invasion,and epithelial-mesenchymal transformation and promotes their apopto-sis.In addition,clinical data showed that the abnormal expression of KCNH2 in PC was related to the tumor stage.Patients with high expression of KCNH2 had a poor prognosis.Conclusions:KCNH2 is expected to be a novel targeted molecule in treating PC.

一例KCNH2基因变异导致长QT综合征患者的遗传学分析

分析一例长QT综合征(Long QT syndrome,LQTS)患者的临床表型和基因变异,明确其可能的致病机制。方法 收集患者本人的外周血,对其进行全外显子组测序和基因变异分析,采用Sanger测序对致病变异进行验证。结果 通过全外显子组测序发现患者KCNH2基因上存在一处杂合变异c.160T>C(p.Y54H),根据美国医学遗传学与基因组学学会(American College of Medical Genetics and Genomics,ACMG)指南(PS1+PM1+PM2+PP2+PP3)可判定为致病性变异。结论 KCNH2基因上的错义突变c.160T>C(p.Y54H)是导致患者出现LQTS临床表型的主要原因,本研究丰富了KCNH2基因在中国人群中的突变谱。

长QT综合征发病机制研究新进展

长QT综合征（LQTS）是一种常于青少年发病的遗传性心律失常,迄今为止已发现20个致病基因.其中LQT1 ～3占约80％,致病基因分别为KCNQ1（IKs）、KCNH2（IKr）、SCN5A （Na）,故关于基因筛查专家共识建议只筛查LQT1～3.在3个主要亚型中,目前研究最多的是LQT2.主要涉及的机制有突变导致蛋白转运障碍、无义介导的mRNA衰减、翻译重启造成N端截短蛋白、影响PAS域蛋白折叠及与其他部分的相互关系、全长Kv11.1a异构体转换为C端截短的Kv1 1.1 a-USO等.也探讨了对应这些机制的基因特异性治疗策略.

快速激活延迟整流钾离子通道a亚基F129I突变致长QT综合征机制研究

目的:通过对1例长QT综合征2型患者疑似致病突变KCNH2(F129I)细胞电生理学研究,探究其细胞电生理学发病机制。方法:采用目标区域捕获高深度测序技术进行候选基因突变筛查;以脂质体转染技术通过HEK293细胞表达可疑致病突变。应用全细胞膜片钳技术记录HERG通道电流。结果:候选基因测序发现KCNH2基因第385核苷酸位点T>A杂合子错义突变,导致第129位密码子由苯丙氨酸变为异亮氨酸(F129I),进一步细胞膜片钳研究发现F129I突变型IKr电流密度显著减小,峰值电流抑制率约为野生型的86%。共转染野生型与F129I结果显示IKr电流显著恢复,与野生型差异无统计学意义。结论:本研究通过细胞电生理学研究证实患者携带KCNH2(F129I)致LQT2发生机制为HERG转运障碍,导致IKr功能减弱。

不同基因及突变类型对长QT综合征临床表型的影响

长QT综合征是最常见的遗传性离子通道病,迄今发现的致病基因已有12个,LQT1～12的致病基因分别为KCNQ1、KCNH2、SCN5A、Ankyrin-B、KCNE1、KCNE2、KCNJ2、Cav1.2、CAV3、SCN4B、AKAP9和SNTA1。其中LQT1和LQT2占到总数的75%左右。最近的基因型-表型关系研究表明,对于LQT1本文主要综述这方面的最新进展情况。

Study on the compatibility principle of Wutou Decoction based on network pharmacology

Objective To investigate the underlying drug enhancement mechanisms of the Chuanwu(Aconiti Radix)and Huangqi(Astragali Radix)combination and toxicity reduction of Chuan-wu combined with Gancao(Glycyrrhizae Radix et Rhizoma)in Wutou Decoction(乌头汤,WTD),and to elucidate the compatibility principle.Methods The active compounds and potential effective targets of the selected combinations were retrieved from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP)and Traditional Chinese Medicines Integrated Database(TCMID).The toxicity of Chuanwu(Aconiti Radix)was investigated by selecting all five toxic compounds from the literature and the TCMSP database,and obtaining their targets through SwissTargetPrediction.Targets related to rheumatoid arthritis(RA)were searched using Dis-GeNET,GenCards,and Online Mendelian Inheritance in Man(OMIM).Mutual targets between the drug pairs and RA were selected as potential RA therapy targets.The medicinally active compound-target network was constructed using Cytoscape 3.9.0.Gene ontology(GO)term enrichment and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrich-ment were performed using the Database for Annotation,Visualization,and Integrated Dis-covery(DAVID)platform.Results We obtained 191 active compound targets for Gancao(Glycyrrhizae Radix et Rhizoma),171 for Huangqi(Astragali Radix),and 103 for Chuanwu(Radix Aconiti)(hypo-aconitine’s target was obtained through literature and SwissTargetPrediction).A total of 5872 genes were obtained for RA.A drug-active compound-target network involving 13 effect-en-hancing and nine toxicity reduction targets was constructed.PGR was the main effect en-hancement target,and KCNH2 was the main toxicity reduction target.The effect-enhancing targets were related to 23 GO terms(such as positive regulation of transcription from RNA polymerase II promoter,steroid hormone-mediated signaling pathway,plasma membrane,and protein binding)(P<0.01),and 13 KEGG pathways related to synergism[such as estro-gen signaling pathway,cholinergic synapse,and phosphatidylinositol 3-kinase/protein kinase B(PI3K/Akt)signaling pathway].The toxicity reduction targets were related to 28 GO terms(mainly involes G-protein coupled receptor signaling pathway,plasma membrane,and drug binding)(P<0.01),and five KEGG pathways related to toxicity reduction(cholinergic syn-apse,calcium signaling pathway,regulation of actin cytoskeleton,neuroactive ligand-recept-or interaction,and serotonergic synapse).Conclusion The combination of Chuanwu(Aconiti Radix)and Huangqi(Astragali Radix)plays an important effect-enhancing role in WTD and involves the estrogen and PI3K/Akt sig-naling pathways,with PGR as the core.The Chuanwu(Aconiti Radix)and Gancao(Gly-cyrrhizae Radix et Rhizoma)combination decreases toxicity in WTD and is associated with the cholinergic synapse and calcium signaling pathways,with KCNH2 as the core.

非获得性长QT综合征的表观遗传学机制

非获得性长QT综合征(cLQTS)是一种或可威胁生命的心律失常,其特征是心肌复极化延迟而导致的QT间期延长。现代研究证明,cLQTS的发生可增加尖端扭转型室性心动过速(TdP)-晕厥的发生率,导致感音性听力丧失,并可增加健康人群罹患癫痫及心源性猝死(SCD)的风险。因此,了解cLQTS的表观遗传学机制,对于改善本病诊断和治疗,防治cLQTS相关疾病极为必要。本病发病机制复杂,其遗传模型亦复杂多态,迄今为止发现至少有13个基因与本病的发病密切相关,其中3个主要基因(KCNQ1,KCNH2和SCN5A)约占本病发病的90%。故本文从cLQTS 3个主要基因角度深入探讨非获得性QT综合征的发病机制,以期对cLQTS及相关疾病的诊断筛查提供科学思路。