中文摘要：

目的：分析散发性扩张型心肌病（dilated cardiomyopathy,DCM）相关TBX20基因突变谱。方法：从中国汉族人群中选择105例散发性DCM患者和130名健康对照者,采集静脉血并使用核酸纯化试剂盒纯化基因组DNA,采用PCR试剂扩增TBX20基因的全部编码外显子,对扩增的TBX20基因片段进行测序,将所得序列与GenBank数据库中的TBX20基因序列进行对比,借助MUSCLE分析突变氨基酸在进化上的保守性,应用MutationTaster和PolyPhen-2预测突变的致病性。结果：在1例散发性DCM患者识别出了1个新的杂合性TBX20基因变异c.832G〉A,即p.D278N突变,但该突变在130名对照者和其他散发性DCM患者中均未检出。跨物种TBX20蛋白序列比对分析表明,第278位的天冬氨酸在进化上保守,该TBX20基因突变具有致病性。结论：发现散发性DCM相关TBX20基因新致病性突变c.832G〉A,将有助于DCM患者的遗传咨询和个体化处理。

英文摘要：

Objective：To analyze the mutational spectrum of TBX20 associated with sporadic dilated cardiomyopathy（DCM）. Methods：A cohort of 105 unrelated patients with sporadic DCM and130 unrelated healthy control subjects were recruited from the Chinese Han population,from whom the venous blood samples were drawn,and the genomic DNA was extracted with a DNA extraction kit.Amplification of the whole coding exons of the TBX20 gene was made by using polymerase chain reaction reagents.The amplified TBX20 fragments were sequenced with a sequencing kit.The shown sequences were aligned with those of TBX20 released from the GenBank to identify a TBX20 mutation.The online soft MUSCLE was used to estimate whether the mutated amino acid was conserved evolutionarily.The online programs MutationTaster and PolyPhen-2 were used to predict the pathogenicity of the mutation.Results：A novel heterozygous TBX20 mutation c.832G〉A,which was equivalent to p.D278 N,was detected in a patient with sporadic DCM.The missense mutation was absent both in the 130 control individuals and other sporadic DCM patients.Trans species sequence alignment analysis of TBX20 protein showed that the 278 th position of aspartic acid was conserved evolutionarily.The mutation was predicted to be pathogenic. Conclusions：This study reveals a novel TBX20 mutation c.832G〉A associated with sporadic DCM,contributing to the genetic counseling and personalized treatment of DCM.