目的　探讨与Leber’s遗传性视神经病变 (Leber’shereditaryopticneuropathy ,LHON)相关的线粒体DNA原发位点突变在视神经疾病中的诊断意义。方法　 79例各种原因引起的双侧视神经疾病中 ,16例为临床诊断的LHON患者 ,44例为可疑LHON患者 ,2例为酒精性弱视患者 ,4例为多发性硬化症患者 ,5例为常染色体显性遗传的视神经萎缩患者 ,4例为原发性开角型青光眼患者 ,3例为脊髓小脑退行性变和 1例乙胺丁醇引起的视神经萎缩患者。用聚合酶链反应 (polymerasechainreaction ,PCR)及限制性片段长度多态性技术 ,检测外周血DNA中提取的线粒体DNA的 3 46 0位点、11778位点及 144 84位点 ,分析 3个原发位点的突变。结果　 31例 (39 2 % )呈 11778位点突变阳性 ,其中包括 16例临床诊断为LHON的患者、13例 (2 9 5 % )可疑LHON患者及 2例酒精性弱视患者。余 48例均未检出上述 3个原发位点突变。结论　线粒体DNA的检测分析为确立或排除LHON提供了诊断依据 ,尤其是对无家族史或原因不明的双侧性视神经炎的患者更具有诊断价值。 Objective To investigate the diagnostic value of mitochondrial DNA primary site mutation associated with Leber’s hereditary optic neuropathy (LHON) in optic neuropathy. Methods A total of 79 cases of bilateral optic neuropathy caused by various causes were diagnosed in 16 patients with LHON, 44 with suspected LHON, 2 with alcohol-induced amblyopia, 4 with multiple sclerosis and 5 with Patients with autosomal dominant optic atrophy included 4 patients with primary open-angle glaucoma, 3 patients with spinocerebellar degeneration and 1 patient with optic nerve atrophy caused by ethambutol. The 3 46 0, 11 778 and 144 84 loci of mitochondrial DNA extracted from peripheral blood DNA were detected by polymerase chain reaction (PCR) and restriction fragment length polymorphism (PCR-RFLP). Three primary Site mutations. Results 31 (39.2%) patients showed a positive mutation of 11778 loci, including 16 patients diagnosed as LHON, 13 (195%) suspicious LHON patients and 2 alcoholic amblyopia patients. The remaining 48 cases were not detected the above three mutations in the primary site. Conclusion The detection and analysis of mitochondrial DNA provide a diagnostic basis for the establishment or exclusion of LHON, especially for patients with no family history or unexplained bilateral optic neuritis.