一例短QT综合征患者HERG基因的突变筛查

Analysis of HERG gene in a patient with short-QT syndrome

目的研究HERG基因是否是1例有家系的短QT综合征患者的致病基因。方法1例30岁女性患者,以室颤和心源性晕厥起病,ECG提示有QT间期缩短,血电解质及心脏结构正常。其母亲与女儿均有QT间期缩短。诊断为短QT综合征。本研究提取该患者基因组DNA,应用PCR方法扩增HERG基因的16个外显子编码区和邻近序列,PCR产物纯化后,经ABI PRISM3700 DNA全自动测序仪直接测序,然后与NCBI数据库中HERG基因的序列进行比较。结果本研究发现8个多态性位点(SNP),其中7个在NCBI的SNP库中均有报道,1个是新的,位于第8个外显子上,T/C杂合,不引起编码氨基酸的改变。未在HERG基因上发现有意义的突变。结论HERG基因不是该例短QT综合征患者的致病基因。

AIM To screen the HERG gene mutation in a patient with familial short QT-interval syndrome. METHODS A 30-year-old woman presented with idiopathic ventricular fibrillation and cardiac syncope. Her QT interval in the ECG was abnormally short without perceived electrolytes and cardiac structural abnormalities. The ECG of her mother and daughter also suggested short QT interval. The patient was diagnosed as having short-QT syndrome. Genomic DNA was isolated from the patientg peripheral blood. The 16 exons and the intron-exon boundaries of HERG were amplified by the polymerase chain reaction assay and the polymerase chain reaction products were purified and were directly sequenced with the use of ABI PRISM 3700 Automatic DNA Sequencer. RESULTS Eight single nucleotide polymorphisms （SNPs） were found, among which 7 SNPs had been listed in the Single Nucleotide Polymorphism National Center for Biotechnology Information （SNP NCBI） database and one SNP was new： one base pair in the exon HERG-E-8-3 was substituted by mutation of heterozygosis of T/C without changes of the encoding amino acids in the Ikr channel. No disease casing mutation was found in HERG gene. CONCLUSION HERG gene is not related to the familial short-QT syndrome in this patient.