Leber遗传性视神经病变的临床特征及线粒体突变位点分析

Clinical phenotype and maternal mutation analysis of Leber hereditary optic neuropathy

背景 Leber遗传性视神经病变（LHON）是一种线粒体脱氧核糖核酸（mtDNA）变异而导致的母系遗传疾病,其常见的突变位点有m.3460 G＞A,m.11778 G＞A和m.14484 T＞C,其他突变类型较为少见,而了解患者的mtDNA突变位点对于患者的治疗有重要的临床意义. 目的 结合LHON患者的发病特点检测和分析其线粒体突变位点.方法 纳入2010-2014年在北京大学人民医院确诊的无亲缘关系的12例LHON患者,对患者的双眼进行视力、视野、眼前节、视觉诱发电位、眼底等眼科检查.采集患者肘静脉血4 ml,采用PCR法对患者的mtDNA进行扩增并测序,对患者携带的3个常见突变位点和其他突变位点进行分析.结果 12例患者中男11例,女1例;双眼视力同时下降者7例,左眼先发病者3例,右眼先发病者1例.患者左右眼间视力损害程度比较无明显差异.患者近视力为看不到J7者18眼,近视力为J7者3眼,近视力为J6者2眼,近视力为J2者1眼.患者远视力为手动/眼前者1眼,光感者1眼,0.01 ～0.1者18眼,0.12～ 0.3者2眼.患者鼻侧视野严重缺损者7眼,颞侧视野严重缺损者3眼,中央视野严重缺损者8眼.12例患者的mtDNA测序发现,m.3460 G＞A突变者3例,m.11778 G＞A突变者5例,m.14484 T＞C突变者2例,2例患者无上述3个常见位点突变,分别为MT-ND1和MT-ND4L基因的序列突变,其突变位点分别为m.3497 C＞T和m.10663 T＞C. 结论 LHON患者中以男性多见,患者双眼间视力下降的程度不同,多数患眼近视力损害更为严重.视野损害以中心区较为多见.本研究中发现了中国人群中LHON患者的少见线粒体基因m.3497C＞T和m.10663 T＞C位点突变.

Background Leber hereditary optic neuropathy （LHON） is a maternally inherited disease caused by mitochondrial DNA （mtDNA） mutation with the common mutation sites of m.3460 G〉A,m.11778 G〉A and m.14484 T〉C,and other mutation sites are rare.Understanding the mutation type of mtDNA in LHON patients has an important clinical significance.Objective This study was to analyze the clinical features of LHON and detect the mitochondrial mutation.Methods Twelve unrelated Chinese patients who was diagnosed as LHON were included in Peking University People＆#39;s Hospital from 2010 to 2014.The visual acuity,perimetry,ocular segment,visual evoked potential,fundus were binocularly examined.The peripheral blood of 4 ml was collected from each patient and mtDNA was amplified and sequenced by using PCR.Three common genetic mutation sites for LHON and other mutation sites were determined and analyzed.This study protocol was approved by Ethic Committee of Peking University People＆#39;s Hospital and complied with Helsinki Declaration.Written informed consent was obtained from each patient prior to any medical examination.Results Of the 12 patients,11 were male and 1 was female.The visual acuity of both eyes reduced simultaneously in 7 patients,and the visual acuity of left eye and the right eye first reduced in 3 patients and 1 patient,respectively.There was no significant correlation in the visual impairment between the left and right eyes （P〉0.05）.In the near vision of the patients,J7 was invisible in 18 eyes,and J7 were obtained in 3 eyes,J6 were obtained in 2 eyes and J2 was obtained in 1 eye.In the distant vision of the patients,hand movement was obtained in 1 eye,light perception was obtained in 1 eye,0.01-0.1 were obtained in 18 eyes and 0.12-0.3 were obtained in 2 eyes.The visual field defect of nasal lateral was found in 7 eyes,visual field defect of temporal lateral was found in 3 eyes and the visual field defect of central was found in 8 eyes.mtDNA sequencing revealed that m.3460 G〉A mutation was seen in 3 patients,m.11778 G〉A mutation was seen in 5 patients and m.14484 T〉C mutation was seen in 2 patients.In addition,other 2 mutations were found in 2 patients,which were m.3497 C〉T and m.10663 T〉C mutations at the MT-ND1 and MT-ND4L genes,respectively.Conclusions LHON is more common in male.Visual impairment shows the varying degrees between both eyes of patients and appears to be severe in near vision.Central visual field defect is common in LHON patients.This study detects m.3497 C〉T and m.10663 T〉C mutation in Chinese LHON patients.