【摘要】 目的　对 3个先天性长 QT综合征 ( long QT syndrome,L QTS)家族成员进行基因诊断。方法　应用位于 H ERG和 SCN5 A基因内和邻近的短串联重复序列 ( shorttandem repeat,STR)位点确定染色体单体型 ,对 3个汉族 L QTS家系进行单体型连锁分析。结果　临床诊断患者 15例 (其中 3例死亡 ) ,疑似患者 11例。单体型连锁分析结果 :L QTS患者 14例 ,排除 2例假阳性患者和 7例疑似患者。家系 1的致病基因位于 SCN5 A,家系 2和家系 3的致病基因位于 H ERG。结论　单体型连锁分析能为 L QTS基因分型和症状前诊断提供有效手段。更多还原

【Abstract】 Objective Three long QT syndrome(LQTS) pedigrees were brought together for genetic diagnosis by using short tandem repeat(STR) markers. Methods Genomic DNA was extracted from blood samples. STR markers (D7S1824, D7S2439, D7S483, D3S1298, D3S1767, D3S3521) in or spanning the HERG and SCN5A gene were amplified; the haplotype analysis for LQTS was performed. Results Clinical diagnosis showed that 15 are LQTS patients (3 died) and 11 are probable patients. Linkage analysis showed that LQTS patients are linked with the SCN5A gene in family 1, HERG is linked with the disease in family 2 and 3. Fourteen gene carriers were identified, 2 patients and 7 probable patients were excluded. Conclusion Linkage analysis using STR markers can serve as useful tool for presymptomatic diagnosis.更多还原