基因检测在肥厚型心肌病诊断治疗及预后评价的应用进展

精选优质文档倾情为你奉上精选优质文档倾情为你奉上专心专注专业专心专注专业精选优质文档倾情为你奉上专心专注专业基因检测在肥厚型心肌病诊断、治疗及预后评估的应用进展翟姗姗（1）樊朝美*（2）李一石（3）肥厚型心肌病（HypertrophicCardiomyopathy，HCM）是指并非完全因心脏负荷异常引起而发生的，以室壁厚度增加为表现的遗传性心肌病ADDINEN.CITEADDINEN.CITE.DATA[1]，亦是青少年及运动员心源性猝死（SuddenCardiacDeath，SCD）的主要原因，故尽早诊断、治疗尤为重要。基因检测有助于HCM早期诊断，但一代测序技术的低检出率及高成本限制了其在临床中的应用，近年来二代测序技术（NextGenerationSequencing,NGS）的广泛应用弥补了一代测序技术的不足。本文就基因检测在HCM诊断、治疗及预后评估的应用进展做一综述。基因检测技术的进展传统的化学降解法、双脱氧链终止法以及在它们的基础上发展来的各种DNA测序技术统称为第一代DNA测序技术。因为成本高、速度慢、序列少的第一代测序技术已经不能满足深度测序和重复测序等大规模基因组测序的需求。所以，以高通量为特点的第二代测序技术应运而生，其原理为边合成边测序，可快速并低成本地获得大规模DNA序列信息。第二代基因测序（NextGenerationSequencing，NGS）主要有以下方式：（1）靶向基因测序（TargetSequencingInCustomDisease-SpecificPanels，Target-NGS）是对特定疾病的所有已知致病基因进行测序，主要用于诊断；（2）全外显子测序（Whole-ExomeSequencing，WES）是对基因所有编码区进行测序，主要用于明确可疑遗传性疾病的致病突变，尤其是Target-NGS无法测得突变时；（3）全基因组测序（Whole-GenomeSequencing,WGS）是指对全基因组30亿bpDNA测序，包括编码区及非编码区，主要是用来明确新发致病基因与疾病的关系，在一个个体中可发现成千上万的突变，其中大部分突变与临床无明确相关性，应用WGS最大的挑战是如何找到与临床密切相关的突变。如何处理二道测序所得庞大数据，如何严谨分析并解释新发突变的致病性均是NGS所应对的问题ADDINEN.CITEADDINEN.CITE.DATA[2]。基因检测在HCM诊断与鉴别诊断中的作用肥厚型心肌病基因检测最初仅限于实验室研究，现代基因测序不仅用于HCM的诊断与鉴别诊断，亦可用于优生优育及预后的评估。随着NGS在HCM中的广泛应用，不仅能够发现更多非常见的肌节蛋白突变，还能发现非HCM致病突变如桥粒蛋白突变、离子通常蛋白突变，另外NGS亦可检出拟表型基因突变。如，Fabry病的α半乳糖苷酶基因（α-galactosidaseA，GLA）突变ADDINEN.CITEADDINEN.CITE.DATA[3]，这有助于HCM的鉴别诊断。除此之外，NGS还能够发现结构变异（StructureVariants，SV）、拷贝数变异（Copynumbervariation,CNV）ADDINEN.CITE<EndNote><Cite><Author>Lopes</Author><Year>2015</Year><RecNum>231</RecNum><DisplayText><styleface="superscript">[4]</style></DisplayText><record><rec-number>231</rec-number><foreign-keys><keyapp="EN"db-id="vpvs2t0rjxvsriepf29xs9aswr525zzv95pw"timestamp="">231</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Lopes,L.R.</author><author>Murphy,C.</author><author>Syrris,P.</author><author>Dalageorgou,C.</author><author>McKenna,W.J.</author><author>Elliott,P.M.</author><author>Plagnol,V.</author></authors></contributors><auth-address>InheritedCardiovascularDiseaseUnit,InstituteofCardiovascularScience,UCL,London,UK;CardiovascularCentre,UniversityofLisbon,Lisbon,Portugal. UCLGeneticsInstitute,UCL,London,UK. InheritedCardiovascularDiseaseUnit,InstituteofCardiovascularScience,UCL,London,UK. UCLGeneticsInstitute,UCL,London,UK.Electronicaddress:v.plagnol@ucl.ac.uk.</auth-address><titles><title>Useofhigh-throughputtargetedexome-sequencingtoscreenforcopynumbervariationinhypertrophiccardiomyopathy</title><secondary-title>EurJMedGenet</secondary-title><alt-title>Europeanjournalofmedicalgenetics</alt-title></titles><periodical><full-title>EurJMedGenet</full-title><abbr-1>Europeanjournalofmedicalgenetics</abbr-1></periodical><alt-periodical><full-title>EurJMedGenet</full-title><abbr-1>Europeanjournalofmedicalgenetics</abbr-1></alt-periodical><dates><year>2015</year><pub-dates><date>Oct9</date></pub-dates></dates><isbn>1878-0849(Electronic) 1769-7212(Linking)</isbn><accession-num></accession-num><urls><related-urls><url>/pubmed/</url></related-urls></urls><electronic-resource-num>10.1016/j.ejmg.2015.10.001</electronic-resource-num></record></Cite></EndNote>[4]，以及表观遗传学中DNA甲基化水平和组蛋白修饰因子的改变，探讨这些结果的临床意义将有助于解释HCM的异质性。基因检测有助于解释HCM的异质性HCM异质性突出是临床面临的重大挑战。HCM患者可无症状，也可早期发生心力衰竭和猝死，这种异质性可能受以下因素的影响：（1）致病基因不同；（2）致病突变所累及氨基酸位置不同；（3）修饰因子的影响ADDINEN.CITEADDINEN.CITE.DATA[5]。致病突变可能与心室形态相关：早期研究提示HCM的室间隔呈反向曲线形者较乙状形者的突变阳性率更高（79%比8%），BosJM等ADDINEN.CITE<EndNote><Cite><Author>Bos</Author><Year>2007</Year><RecNum>236</RecNum><IDText>193-9</IDText><DisplayText><styleface="superscript">[6]</style></DisplayText><record><rec-number>236</rec-number><foreign-keys><keyapp="EN"db-id="vpvs2t0rjxvsriepf29xs9aswr525zzv95pw"timestamp="">236</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Bos,J.M.</author><author>Ommen,S.R.</author><author>Ackerman,M.J.</author></authors></contributors><auth-address>MayoClinicWindlandSmithRiceSuddenDeathGenomicsLaboratory,MayoClinicCollegeofMedicine,Rochester,MN,USA.</auth-address><titles><title>Geneticsofhypertrophiccardiomyopathy:one,two,ormorediseases?</title><secondary-title>CurrOpinCardiol</secondary-title><alt-title>Currentopinionincardiology</alt-title></titles><periodical><full-title>CurrOpinCardiol</full-title><abbr-1>Currentopinionincardiology</abbr-1></periodical><alt-periodical><full-title>CurrOpinCardiol</full-title><abbr-1>Currentopinionincardiology</abbr-1></alt-periodical><pages>193-9</pages><volume>22</volume><number>3</number><keywords><keyword>ActinCytoskeleton</keyword><keyword>Cardiomyopathy,Hypertrophic/diagnosis/*genetics/physiopathology</keyword><keyword>Death,Sudden,Cardiac/etiology</keyword><keyword>GeneticResearch</keyword><keyword>Genotype</keyword><keyword>HeartSeptum/physiopathology</keyword><keyword>Humans</keyword><keyword>Mutation</keyword><keyword>Phenotype</keyword></keywords><dates><year>2007</year><pub-dates><date>May</date></pub-dates></dates><isbn>0268-4705(Print) 0268-4705(Linking)</isbn><accession-num></accession-num><urls><related-urls><url>/pubmed/</url></related-urls></urls><electronic-resource-num>10.1097/HCO.0b013e3280e1cc7f</electronic-resource-num></record></Cite></EndNote>[6]发现其原因在于反向曲线形肥厚的HCM患者多为肌节蛋白基因突变所致，乙状形肥厚的HCM患者多为Z盘基因突变所致。LopesLR等ADDINEN.CITEADDINEN.CITE.DATA[7]进一步发现细胞膜锚蛋白基因（ankyrin-B，ANK2）所致的HCM患者室间隔最大厚度增加。HCM基因型与心脏核磁共振成像对照研究表明，局部心肌纤维化在基因型阳性的HCM患者中较基因型阴性者中更为常见，而弥漫心肌纤维化与之相反ADDINEN.CITEADDINEN.CITE.DATA[8]。以上研究表明，特定蛋白突变或突变数量的改变与HCM心室形态有一定相关性。肥厚型心肌病与其他遗传性心肌病的致病基因突变重叠：HaasJ等ADDINEN.CITEADDINEN.CITE.DATA[9]应用Target-NGS技术发现扩张型心肌病、肥厚型心肌病、离子通道心肌病等致病突变的重叠比例很高。SchaeferE等ADDINEN.CITEADDINEN.CITE.DATA[10]对一个6月大小猝死的左室致密化不全患者进行NGS测序分析，发现其携带肌球蛋白结合蛋白C（MyosinBindingProteinC，MYBPC3）双复合突变（Lys505del,、Pro955fs）。GirolamiF等ADDINEN.CITEADDINEN.CITE.DATA[11]对一HCM合并早发房性心律失常的家系进行Target-NGS分析，检测到新发的α-辅肌动蛋白-2（actininalpha2，ACTN2）为其致病突变，WangLF等ADDINEN.CITEADDINEN.CITE.DATA[12]对一HCM合并长QT综合征（LongQTsyndrome，LQT）的家系进行分析，发现该家系同时存在LQT1与HCM致病突变。通过对SCD高危人群的基因型进行分析发现，其多突变比例较多ADDINEN.CITE<EndNote><Cite><Author>Kelly</Author><Year>2009</Year><RecNum>102</RecNum><IDText>182-90</IDText><DisplayText><styleface="superscript">[13]</style></DisplayText><record><rec-number>102</rec-number><foreign-keys><keyapp="EN"db-id="vpvs2t0rjxvsriepf29xs9aswr525zzv95pw"timestamp="">102</key><keyapp="ENWeb"db-id="">0</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Kelly,M.</author><author>Semsarian,C.</author></authors></contributors><auth-address>AgnesGingesCentreforMolecularCardiology,CentenaryInstitute,Newtown,Sydney,NSW2042,Australia.</auth-address><titles><title>Multiplemutationsingeneticcardiovasculardisease:amarkerofdiseaseseverity?</title><secondary-title>CircCardiovascGenet</secondary-title><alt-title>Circulation.Cardiovasculargenetics</alt-title></titles><periodical><full-title>CircCardiovascGenet</full-title><abbr-1>Circulation.Cardiovasculargenetics</abbr-1></periodical><alt-periodical><full-title>CircCardiovascGenet</full-title><abbr-1>Circulation.Cardiovasculargenetics</abbr-1></alt-periodical><pages>182-90</pages><volume>2</volume><number>2</number><keywords><keyword>Animals</keyword><keyword>CardiovascularDiseases/*genetics/*pathology</keyword><keyword>GeneticMarkers</keyword><keyword>Humans</keyword><keyword>*Mutation</keyword><keyword>SeverityofIllnessIndex</keyword></keywords><dates><year>2009</year><pub-dates><date>Apr</date></pub-dates></dates><isbn>1942-3268(Electronic) 1942-3268(Linking)</isbn><accession-num></accession-num><urls><related-urls><url>/pubmed/</url></related-urls></urls><electronic-resource-num>10.1161/CIRCGENETICS.108.</electronic-resource-num></record></Cite></EndNote>[13]。随着NGS在临床中的进一步应用，有可能发现更多不同心肌病之间致病基因的重叠现象，这很有可能是所有遗传性心脏病异质性的一个重要原因。目前关于基因型-表型的关系暂无定论，相信随着大样本多中心HCM基因型随访研究的开展，将有助于揭示基因型-表型的关系。基因检测在HCM治疗中的作用4.1药物治疗的新视点药物、酒精消融术及手术治疗可以改善HCM患者的症状并提高生活质量。但并不能够逆转有病变的心肌，亦不能改善HCM患者的长期预后。为解决以上问题，已开展了一些新治疗药物的探索性研究，并发现氯沙坦、辛伐他汀、螺内酯以及抗氧化剂N-乙酰半胱氨酸等可以减轻HCM小鼠心肌纤维化程度和减少胶原成分，而这些HCM小鼠均是特定致病突变转基因所建立的模型。因此，将来基因检测结果可以影响HCM的治疗ADDINEN.CITE<EndNote><Cite><Author>Ho</Author><Year>2010</Year><RecNum>155</RecNum><IDText>2430-40;discussion2440</IDText><DisplayText><styleface="superscript">[14]</style></DisplayText><record><rec-number>155</rec-number><foreign-keys><keyapp="EN"db-id="vpvs2t0rjxvsriepf29xs9aswr525zzv95pw"timestamp="">155</key><keyapp="ENWeb"db-id="">0</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Ho,C.Y.</author></authors></contributors><auth-address>CardiovascularGeneticsCenter,CardiovascularDivision,BrighamandWomen'sHospital,HarvardMedicalSchool,Boston,MA02115,USA.cho@</auth-address><titles><title>Geneticsandclinicaldestiny:improvingcareinhypertrophiccardiomyopathy</title><secondary-title>Circulation</secondary-title><alt-title>Circulation</alt-title></titles><periodical><full-title>Circulation</full-title><abbr-1>Circulation</abbr-1></periodical><alt-periodical><full-title>Circulation</full-title><abbr-1>Circulation</abbr-1></alt-periodical><pages>2430-40;discussion2440</pages><volume>122</volume><number>23</number><keywords><keyword>Cardiomyopathy,Hypertrophic/*diagnosis/*genetics/therapy</keyword><keyword>GeneticPredispositiontoDisease/*genetics</keyword><keyword>GeneticTesting/methods/*trends</keyword><keyword>Humans</keyword><keyword>PatientCare/methods/*trends</keyword><keyword>TreatmentOutcome</keyword></keywords><dates><year>2010</year><pub-dates><date>Dec7</date></pub-dates></dates><isbn>1524-4539(Electronic) 0009-7322(Linking)</isbn><accession-num></accession-num><urls><related-urls><url>/pubmed/</url></related-urls></urls><custom2></custom2><electronic-resource-num>10.1161/CIRCULATIONAHA.110.</electronic-resource-num></record></Cite></EndNote>[14]。另外，亦有研究表明在MYH7-Arg403Gln或MYH7-Arg719Trp转基因小鼠发生左室肥厚前，分别给予地尔硫卓、氯沙坦，可以减轻心肌纤维化程度并可延缓左室肥厚的进程ADDINEN.CITE<EndNote><Cite><Author>Ho</Author><Year>2010</Year><RecNum>155</RecNum><IDText>2430-40;discussion2440</IDText><DisplayText><styleface="superscript">[14]</style></DisplayText><record><rec-number>155</rec-number><foreign-keys><keyapp="EN"db-id="vpvs2t0rjxvsriepf29xs9aswr525zzv95pw"timestamp="">155</key><keyapp="ENWeb"db-id="">0</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Ho,C.Y.</author></authors></contributors><auth-address>CardiovascularGeneticsCenter,CardiovascularDivision,BrighamandWomen'sHospital,HarvardMedicalSchool,Boston,MA02115,USA.cho@</auth-address><titles><title>Geneticsandclinicaldestiny:improvingcareinhypertrophiccardiomyopathy</title><secondary-title>Circulation</secondary-title><alt-title>Circulation</alt-title></titles><periodical><full-title>Circulation</full-title><abbr-1>Circulation</abbr-1></periodical><alt-periodical><full-title>Circulation</full-title><abbr-1>Circulation</abbr-1></alt-periodical><pages>2430-40;discussion2440</pages><volume>122</volume><number>23</number><keywords><keyword>Cardiomyopathy,Hypertrophic/*diagnosis/*genetics/therapy</keyword><keyword>GeneticPredispositiontoDisease/*genetics</keyword><keyword>GeneticTesting/methods/*trends</keyword><keyword>Humans</keyword><keyword>PatientCare/methods/*trends</keyword><keyword>TreatmentOutcome</keyword></keywords><dates><year>2010</year><pub-dates><date>Dec7</date></pub-dates></dates><isbn>1524-4539(Electronic) 0009-7322(Linking)</isbn><accession-num></accession-num><urls><related-urls><url>/pubmed/</url></related-urls></urls><custom2></custom2><electronic-resource-num>10.1161/CIRCULATIONAHA.110.</electronic-resource-num></record></Cite></EndNote>[14]。目前HCM的早期干预临床研究相对较少，近期有人将HCM基因型阳性携带者随机分为地尔硫卓治疗组与安慰剂组，2年后发现治疗组左心室壁厚度和质量、舒张期充盈、心肌肌钙蛋白I水平均较安慰剂组有所改善ADDINEN.CITEADDINEN.CITE.DATA[15]。相信随着基因型阳性携带者的大规模随访队列研究的增多将能证实HCM早期干预是否有益。4.2组织工程和再生医学HCM新药开发与设计目前受到两个方面制约，一是缺少能够精准体现HCM病理生理的体外模型；二是业已建立的小鼠动物模型与人类基因组存在一定差异。应用相似于正常心肌结构、生物力学的仿生成分与可分化为HCM心肌细胞的多能干细胞进行研究不仅可以加深对HCM发病机制、基因型与表型相关性的理解。而且，还可行特异突变HCM的药物研究，达到精准治疗的目的ADDINEN.CITE<EndNote><Cite><Author>VunjakNovakovic</Author><Year>2014</Year><RecNum>285</RecNum><DisplayText><styleface="superscript">[16]</style></DisplayText><record><rec-number>285</rec-number><foreign-keys><keyapp="EN"db-id="vpvs2t0rjxvsriepf29xs9aswr525zzv95pw"timestamp="">285</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>VunjakNovakovic,G.</author><author>Eschenhagen,T.</author><author>Mummery,C.</author></authors></contributors><auth-address>MikatiFoundationMikatiFoundation,ColumbiaUniversity,NewYork,NewYork10032.</auth-address><titles><title>Myocardialtissueengineering:invitromodels</title><secondary-title>ColdSpringHarbPerspectMed</secondary-title><alt-title>ColdSpringHarborperspectivesinmedicine</alt-title></titles><periodical><full-title>ColdSpringHarbPerspectMed</full-title><abbr-1>ColdSpringHarborperspectivesinmedicine</abbr-1></periodical><alt-periodical><full-title>ColdSpringHarbPerspectMed</full-title><abbr-1>ColdSpringHarborperspectivesinmedicine</abbr-1></alt-periodical><volume>4</volume><number>3</number><keywords><keyword>BiocompatibleMaterials/therapeuticuse</keyword><keyword>CellDifferentiation</keyword><keyword>Humans</keyword><keyword>Models,Biological</keyword><keyword>Myocardium/*cytology</keyword><keyword>Myocytes,Cardiac/cytology</keyword><keyword>*TissueEngineering</keyword><keyword>ToxicityTests/methods</keyword></keywords><dates><year>2014</year><pub-dates><date>Mar</date></pub-dates></dates><isbn>2157-1422(Electronic)</isbn><accession-num></accession-num><urls><related-urls><url>/pubmed/</url></related-urls></urls><electronic-resource-num>10.1101/cshperspect.a</electronic-resource-num></record></Cite></EndNote>[16]。心脏再生工程中成纤维细胞逆转为正常心肌细胞对于HCM尤为重要，假如在HCM早期就能够成功逆转左心室肥厚，就可以减少心肌纤维化、延缓病程、减少心源性猝死，尽管这种逆转可以实现，但其难度大、效率低。纳米技术可携带包含逆转所需的miRNA和转录因子的载体靶向定位于HCM患者的成纤维细胞并促其逆转，从而达到治疗目的ADDINEN.CITE<EndNote><Cite><Author>Yi</Author><Year>2013</Year><RecNum>298</RecNum><IDText>a</IDText><DisplayText><styleface="superscript">[17]</style></DisplayText><record><rec-number>298</rec-number><foreign-keys><keyapp="EN"db-id="vpvs2t0rjxvsriepf29xs9aswr525zzv95pw"timestamp="">298</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Yi,B.A.</author><author>Mummery,C.L.</author><author>Chien,K.R.</author></authors></contributors><auth-address>CardiovascularResearchCenter,MassachusettsGeneralHospital,Boston,Massachusetts02114.</auth-address><titles><title>Directcardiomyocytereprogramming:anewdirectionforcardiovascularregenerativemedicine</title><secondary-title>ColdSpringHarbPerspectMed</secondary-title><alt-title>ColdSpringHarborperspectivesinmedicine</alt-title></titles><periodical><full-title>ColdSpringHarbPerspectMed</full-title><abbr-1>ColdSpringHarborperspectivesinmedicine</abbr-1></periodical><alt-periodical><full-title>ColdSpringHarbPerspectMed</full-title><abbr-1>ColdSpringHarborperspectivesinmedicine</abbr-1></alt-periodical><pages>a</pages><volume>3</volume><number>9</number><keywords><keyword>Animals</keyword><keyword>CellTransdifferentiation/*physiology</keyword><keyword>Cells,Cultured</keyword><keyword>CellularReprogramming/physiology</keyword><keyword>Humans</keyword><keyword>Mice</keyword><keyword>Models,Animal</keyword><keyword>Myoblasts,Cardiac/*cytology</keyword><keyword>Myocytes,Cardiac/*cytology</keyword><keyword>Regeneration/*physiology</keyword></keywords><dates><year>2013</year><pub-dates><date>Sep</date></pub-dates></dates><isbn>2157-1422(Electronic)</isbn><accession-num></accession-num><urls><related-urls><url>/pubmed/</url></related-urls></urls><custom2></custom2><electronic-resource-num>10.1101/cshperspect.a</electronic-resource-num></record></Cite></EndNote>[17]，此外，纳米技术凭借其高浓度、高选择性、高通透性、高联合性等四大优势，不仅可将特异药物运送到靶向细胞，还可运送特异的基因，可用于研究HCM特异基因致病机制以及相应的治疗方案ADDINEN.CITE<EndNote><Cite><Author>Kumar</Author><Year>2014</Year><RecNum>300</RecNum><IDText>247–298</IDText><DisplayText><styleface="superscript">[18]</style></DisplayText><record><rec-number>300</rec-number><foreign-keys><keyapp="EN"db-id="vpvs2t0rjxvsriepf29xs9aswr525zzv95pw"timestamp="">300</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Kumar,Narenda</author><author>Kumar,Rajiv</author></authors></contributors><titles><title>NanomedicineforTreatmentofCardiovascularDiseasesandStroke-NanotechnologyandNanomaterialsintheTreatmentofLife-ThreateningDiseases-Chapter5</title><secondary-title>NanotechnologyandNanomaterialsintheTreatmentofLife-ThreateningDiseases</secondary-title></titles><periodical><full-title>NanotechnologyandNanomaterialsintheTreatmentofLife-ThreateningDiseases</full-title></periodical><pages>247–298</pages><dates><year>2014</year></dates><urls></urls></record></Cite></EndNote>[18]。基因检测在预后评估中的作用5.1基因检测可否确定良性与恶性突变早期认为肌钙蛋白T（TroponinTtype2，TNNT2）、β肌球蛋白重链（myosin,heavychain7，MYH7）为“恶性突变”，MYBPC3为“良性突变”，以上均为家族性HCM研究，随后大样本散发HCM研究发现上述结论并不成立。MYBPC3与MYH7在发病年龄、肥厚程度、外科手术比例、HCM及猝死家族史等方面并无差异,随后PageSP等ADDINEN.CITEADDINEN.CITE.DATA[19]也发现MYBPC3并非均晚期发病、预后好，这类基因型的HCM临床表型仍存在极大异质性，故不能认为MYBPC3属于“良性突变”。TNNT2基因型的大样本队列研究ADDINEN.CITEADDINEN.CITE.DATA[20]发现该突变患者的心血管死亡风险与正常人群无异，将其认为是“恶性突变”亦不合理的。BosJM等ADDINEN.CITEADDINEN.CITE.DATA[21]发现非肌节蛋突变（MLP/TCAP）所致临床表型与肌节蛋白突变所致HCM并无明显差别。目前的研究发现HCM基因型阳性者比基因型阴性者预后差ADDINEN.CITEADDINEN.CITE.DATA[7]，更易发展为心力衰竭，且发病年龄更早、HCM及SCD家族史更为多见、非对称性左室肥厚比例较多、左室肥厚程度更重、心血管死亡风险加重。目前HCM的良、恶性基因之分还存在很多争议，还不能单纯依据基因测序来决定HCM的预后，仍需用传统临床危险分层的指标来识别HCM的SCD高风险患者。5.2多突变与预后的关系即使在没有传统SCD危险因素时，多突变HCM患者的恶性心律失常、心源性猝死、左室极度肥厚、终末期心力衰竭的发生率等心血管死亡风险均较单基因突变的HCM患者明显升高ADDINEN.CITEADDINEN.CITE.DATA[22]。GirolamiF等ADDINEN.CITEADDINEN.CITE.DATA[23]提出多突变HCM的临床表型加重为基因剂量效应所致，即两种或以上异常基因过度表达叠加产生的效应。但另有研究表明基因突变之间存在相互作用，双突变或多突变在HCM中的致病机制并非为单纯的剂量叠加，而是第二个突变与第一个突变相互作用从而加重表型ADDINEN.CITE<EndNote><Cite><Author>Dorn</Author><Year>2014</Year><RecNum>105</RecNum><IDText>208-10</IDText><DisplayText><styleface="superscript">[24]</style></DisplayText><record><rec-number>105</rec-number><foreign-keys><keyapp="EN"db-id="vpvs2t0rjxvsriepf29xs9aswr525zzv95pw"timestamp="">105</key><keyapp="ENWeb"db-id="">0</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Dorn,G.W.,2nd</author><author>McNally,E.M.</author></authors></contributors><auth-address>FromtheCenterforPharmacogenomics,DepartmentofInternalMedicine,WashingtonUniversitySchoolofMedicine,St.Louis,MO(G.W.D.);andInstituteforCardiovascularResearch,DepartmentofMedicine,TheUniversityofChicago,IL(E.M.M.).emcnally@gdorn@.</auth-address><titles><title>Twostrikesandyou'reout:gene-genemutationinteractionsinHCM</title><secondary-title>CircRes</secondary-title><alt-title>Circulationresearch</alt-title></titles><periodical><full-title>CircRes</full-title><abbr-1>Circulationresearch</abbr-1></periodical><alt-periodical><full-title>CircRes</full-title><abbr-1>Circulationresearch</abbr-1></alt-periodical><pages>208-10</pages><volume>115</volume><number>2</number><keywords><keyword>*AminoAcidSubstitution</keyword><keyword>Animals</keyword><keyword>CardiacMyosins</keyword><keyword>Cardiomyopathy,Hypertrophic,Familial/*genetics</keyword><keyword>Humans</keyword><keyword>*Mutation,Missense</keyword><keyword>MyosinHeavyChains/*genetics</keyword><keyword>*PointMutation</keyword></keywords><dates><year>2014</year><pub-dates><date>Jul7</date></pub-dates></dates><isbn>1524-4571(Electronic) 0009-7330(Linking)</isbn><accession-num></accession-num><urls><related-urls><url>/pubmed/</url></related-urls></urls><custom2></custom2><electronic-resource-num>10.1161/CIRCRESAHA.114.</electronic-resource-num></record></Cite></EndNote>[24]。多突变引起表型加重的机制需在分子、细胞、动物实验中进一步分析，现已发现钙离子通道调节基因表达下调以及转录因子STAT-3的上调与双突变致病性相关ADDINEN.CITE<EndNote><Cite><Author>Kelly</Author><Year>2009</Year><RecNum>102</RecNum><IDText>182-90</IDText><DisplayText><styleface="superscript">[13]</style></DisplayText><record><rec-number>102</rec-number><foreign-keys><keyapp="EN"db-id="vpvs2t0rjxvsriepf29xs9aswr525zzv95pw"timestamp="">102</key><keyapp="ENWeb"db-id="">0</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Kelly,M.</author><author>Semsarian,C.</author></authors></contributors><auth-address>AgnesGingesCentreforMolecularCardiology,CentenaryInstitute,Newtown,Sydney,NSW2042,Australia.</auth-address><titles><title>Multiplemutationsingeneticcardiovasculardisease:amarkerofdiseaseseverity?</title><secondary-title>CircCardiovascGenet</secondary-title><alt-title>Circulation.Cardiovasculargenetics</alt-title></titles><periodical><full-title>CircCardiovascGenet</full-title><abbr-1>Circulation.Cardiovasculargenetics</abbr-1></periodical><alt-periodical><full-title>CircCardiovascGenet</full-title><abbr-1>Circulation.Cardiovasculargenetics</abbr-1></alt-periodical><pages>182-90</pages><volume>2</volume><number>2</number><keywords><keyword>Animals</keyword><keyword>CardiovascularDiseases/*genetics/*pathology</keyword><keyword>GeneticMarkers</keyword><keyword>Humans</keyword><keyword>*Mutation</keyword><keyword>SeverityofIllnessIndex</keyword></keywords><dates><year>2009</year><pub-dates><date>Apr</date></pub-dates></dates><isbn>1942-3268(Electronic) 1942-3268(Linking)</isbn><accession-num></accession-num><urls><related-urls><url>/pubmed/</url></related-urls></urls><electronic-resource-num>10.1161/CIRCGENETICS.108.</electronic-resource-num></record></Cite></EndNote>[13]，这一发现对今后的研究将有极大帮助。随着NGS的应用，HCM双突变率从一代测序技术所发现的5%上升到38%，三突变或更多突变达12.8%ADDINEN.CITEADDINEN.CITE.DATA[9]。虽然还未有研究能证明多突变为独立的危险因素。但是，未来的大样本长期随访研究将给出明确答案。基因检测与一级亲属的筛查先证者亲属基因筛查的前提是先证者的致病突变已明确，值得注意的是，采用一代测序技术能够明确突变的先证者仅占50%，其中很多突变致病性质仍不确定。因此，仅有有限的先证者所在家系可以进行基因筛查。目前基因筛查的主要应用目的为在家族性HCM的家系成员中筛查出基因型阴性的成员并宣告其无发病可能，这样可以减少其心理负担和不必要的长期随访。但是，HCM的“无罪宣告”需要特别谨慎。同时还需向基因型阴性的成员告知如有不适，也需及时就诊。究其原因归为以下四点：（1）既往认为无或不确定致病性的突变有可能为致病突变;（2）先证者可能为多突变，而基因筛查仅进行单个突变的筛查，遗漏了第二个或第三个致病突变;（3）实验室等因素的人为错误;（4）原始突变，初期先证者并无突变，子代新生的原始突变。总之，HCM家系成员基因筛查的应用看似容易，但其结果的解释与建议需要多学科合作方能最为优化ADDINEN.CITEADDINEN.CITE.DATA[25]。基因测序与优生优育产前遗传诊断是指在妊娠初期对患者外周血、羊水及脐带血等进行基因检测，有助于早期发现胎儿是否携带致病基因，但是该方法除在检测时机、准确性、安全性诸多方面仍存在问题外，如何处理基因型阳性携带者还存在医学伦理问题。因为并非所有致病基因携带者在其一生中均会出现临床表型。由于产前遗传诊断在大部分国家非合法，其他手段如收养、人工授精、使用捐赠的配子以及胚胎植入前遗传学诊断（Pre-ImplantationGeneticDiagnosis，PGD）等有助于优生优育。其中，PGD​​可以协助遗传性心肌病的患者孕育不携带致病基因的受精卵胚胎，近期AnverKuliev等对9对遗传性心脏病的夫妻行PGD发现其应用的优势及安全性，尤其是对有青年心源性猝死、ICD植入、室性心动过速、心脏移植等家族史的夫妻有一定帮助，但应用PGD之前必须仔细权衡夫妻的需求ADDINEN.CITEADDINEN.CITE.DATA[26]。总结与展望基因检测有助于HCM早期诊断，二代测序技术不仅能提高致病突变检出率与经济效益比值，还可发现新发的致病突变及突变形式，并进一步揭示基因型与表型的关联性。基因检测在评价HCM预后方面亦有帮助，多突变有可能是HCM患者SCD危险因素之一。尽管心脏组织工程、再生医学、纳米技术处于起步研究阶段，但联合研究将有助于深入了解HCM的发病机制和开发新的治疗药物。参考文献ADDINEN.REFLIST[1] 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