Mitochondrial variants may influence the phenotypic manifestation of Leber's hereditary optic neuropathy-associated ND4 G11778A mutation

We report here the characterization of a five-generation Han Chinese family with Leber＇s hereditary optic neuropathy （LHON）. Strik- ingly, this Chinese family displayed high penetrance and expressivity of visual loss. The average age-of-onset of vision loss was 18 years in this family. Nineteen （11 males/8 females） of 29 matrilineal relatives in this family developed visual loss with a wide range of severity, ranging from blindness to normal vision. Sequence analysis of mitochondrial genome in this pedigree revealed the presence of the ND4 G 11778A mutation and 44 other variants belonging to Asian haplogroup M7b. The G 11778A mutation is present at homoplasmy in matri- lineal relatives of this Chinese family. Of other variants, the C01 G6480A, ND5 T12811C and Cytb A15395G located at highly conserved residues of corresponding polypeptides. In fact, these variants were implicated to be involved in other clinical abnormalities. Here, these variants may act in synergy with the primary LHON-associated Gl1778A mutation. Thus, the mitochondrial dysfunction caused by the primary ND4 G11778A mutation may be worsened by these mitochondrial variants. The results imply that the G6480A, T12811C and A15395G variants might have a potential modifier role in increasing the penetrance and expressivity of the primary LHON-associated G11778A mutation in this Chinese family.

The Mitochondrial DNA Mutation at Position 11778 in Chinese Families with Leber's Hereditary Optic Neuropathy

We amplified the 340 bp of mitochondrial DMA (mtDNA) by PCR including the recognized sequence of restriction enzyme of SfaN I . After amplification and digestion of SfaN I , two bands of 190 bp and 150 bp appeared in the mtDNA of four normal individuals but only one band of 340 bp appeared in the mtDNA with the mutation of G to A at the site of the nucleotide 11778 because such mutation destroyed the recognized sequence of SfaN I . We studied the mtDNAs of the patients with Leber's hereditary optic neur...

Analysis of Mitochondrial Gene Mutations in Chinese Pedigrees of Leber's Hereditary Optic Neuropathy

Purpose:To investigate the frequency of common pathogenic primary mitochondrial DNA mutations in Leber's hereditary optic neuropathy(LHON)families.Methods:Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP)and DNA sequencing were used to detect mitochondrial DNA mutations.Sixty-six Chinese examiners from 15 families,including 22 visual affected and their 44 unaffected maternal relatives,underwent molecular genetic evaluation.Eleven normal individuals underwent evaluation as control.Results:Of the 15 families with suspicion of LHON,13 had nucleotide position(nt)G11778A mutations,2 had nt T14484C mutations.All examiners had nt G11719A mutation.Conclusions:The mutations at nucleotides 11778 and 14484 are primary LHON mutations.Molecular genetic findings suggest that the silent mutation at nt G11719A may be a common genetic polymorphism in Chinese.

Clinical Analysis of Leber's Hereditary Optic Neuropathy Harboring mtDNA Mutation at nt11778

Purpose: To improve our diagnostic technique through the analysis of clinical features ofLeber's heredita'y optic neuropathy (LHON) harboring mtDNA point mutation at nt11778. Methods: Detection of nt11778 mutation was performed on 38 patients clinically diagnosed as LHON in our ophthalmic center from year 1998 to 2000. Circumstances of onset and family history were obtained and ophthalmoscopy, fundus fluorescein angiography, visual field and visual evoked potential were performed on all 38 patients. Result: 30 In 38 patients (78.95 % ) harbor nt11778 mutation, including 28 male (93.33%) and 2 female (6.67%). The ratio of affected male to female is 14: 1. Patients harboring nt11778 mutation display typical clinical nanifestations. Ccnclusion: Identification of one of the three LHON specifically associated ntDNA mutations is essential to confirm the diagnosis. Eye Science 2001: 17:31 ～ 34.

Photoreceptor changes in Leber hereditary optic neuropathy with m.G11778A mutation

·AIM:To evaluate the functional and structural changes of photoreceptors in patients and asymptomatic carriers with Leber hereditary optic neuropathy(LHON)using fullfield electroretinography(FERG)and optical coherence tomography(OCT).·METHODS:Individuals diagnosed with LHON at the Renmin Hospital of Wuhan University and their family members were included in this cross-sectional observational study.The FERG a-wave amplitude of affected patients and asymptomatic carriers was analyzed.The thickness of the outer nuclear layer(ONL),inner and outer segment(IS/OS)and total photoreceptors in the macular fovea and parafovea were measured.·RESULTS:This study included 14 LHON patients(mean age:20.00±9.37y),12 asymptomatic carriers(mean age:39.83±6.48y),and 14 normal subjects(mean age:24.20±1.52y).The FERG results showed that the darkadapted 3.0 electroretinography and light-adapted 3.0 electroretinography a-wave amplitudes of patients and carriers were significantly decreased(P<0.001).The ONL and photoreceptors layers were slightly thicker in patients than in normal subjects(P<0.05),whereas they were thinner in carriers(P<0.05).There were no differences in IS/OS thickness among the groups(P>0.05).·CONCLUSION:Photoreceptors function is significantly impaired in LHON-affected patients and asymptomatic carriers.Meanwhile,photoreceptors morphology is slightly altered,mainly manifesting as a change in ONL thickness.

Stem Cell Ophthalmology Treatment Study (SCOTS)： bone marrow-derived stem cells in the treatment of Leber＇s hereditary optic neuropathy

The Stem Cell Ophthalmology Treatment Study （SCOTS） is currently the largest-scale stem cell ophthal- mology trial registered at ClinicalTrials.gov （identifier： NCT01920867）. SCOTS utilizes autologous bone marrow-derived stem cells （BMSCs） to treat optic nerve and retinal diseases. Treatment approaches include a combination of retrobulbar, subtenon, intravitreal, intra-optic nerve, subretinal, and intravenous injection of autologous BMSCs according to the nature of the disease, the degree of visual loss, and any risk factors related to the treatments. Patients with Leber＇s hereditary optic neuropathy had visual acuity gains on the Early Treatment Diabetic Retinopathy Study （ETDRS） of up to 35 letters and Snellen acuity improvements from hand motion to 20/200 and from counting fingers to 20/100. Visual field improvements were noted. Macular and optic nerve head nerve fiber layer typically thickened. No serious complications were seen. The increases in visual acuity obtained in our study were encouraging and suggest that the use of autolo- gous BMSCs as provided in SCOTS for ophthalmologic mitochondrial diseases including Leber＇s hereditary optic neuropathy may be a viable treatment option.

A Meta-analysis of the association between different genotypes(G11778A, T14484C and G3460A ) of Leber hereditary optic neuropathy and visual prognosis

AIM：To analyze the influences of different genotypes（G11778A,T14484 C and G3460A） of Leber hereditary optic neuropathy（LHON） on visual prognosis. METHODS： After a systematic literature search,all relevant studies evaluating the association between the three primary mutations of LHON and visual prognosis were included.All statistical tests were calculated with Revman 5.2 and STATA 12.0. RESULTS： Ten independent studies were included finally.A significant association between the three primary mutations and prognostic vision over 0.3 were found in G11778 A versus T14484 C [odds ratio（OR） =0.10,95% confidence interval（CI） =0.05-0.17,P 〈0.001],G11778 A versus G3460A（OR=0.18,95%CI=0.09-0.37,P 〈0.001） and T14484 C versus G3460A（OR =2.45,95% CI =1.10-5.48,P 〈0.05）.In addition,obtained by pairwise comparison,the vision during onset,age of onset and sex ratio of these three kinds of patients,have no statistical significance（P 〉0.05）.CONCLUSION： From pairwise comparison,we conclude that these three different genotypes of LHON are related to patients＇ visual prognosis.The T14484 C patients might have a best prognostic vision,G3460 A second,and G11778 A worst.And there is little relation between the three different genotypes and patients＇ vision,age of onset and sex ratio.

Foveal pit morphological changes in asymptomatic carriers of the G11778A mutation with Leber’s hereditary optic neuropathy

AIM:To investigate the foveal pit morphology changes in unaffected carriers and affected Leber’s hereditary optic neuropathy(LHON)patients with the G11778 A mutation from one family.METHODS:This study was a prospective cross-sectional study.Both eyes from 16 family members(age from 9 to 47 y)with the G11778 A mutation were analyzed and compared with 1 eye from 20 normal control subjects.Eleven family members with the G11778 A mutation but without optic neuropathy were classified as unaffected carriers(n=22 eyes).Five family members(n=10 eyes)expressed the LHON phenotype and were classified as affected patients.Retinal images of all the subjects were taken by optical coherence tomography(OCT),and an automatic algorithm was used to segment the retina to eight layers.Horizontal and vertical OCT images centered on the fovea were used to measure intra-retinal layer thicknesses and foveal morphometry.RESULTS:Thicker foveal thickness,thinner foveal pit depth,and flatter foveal slopes were observed in unaffected carriers and affected LHON patients(all P<0.001).Further,the slopes of all four sectors in the LHON were flatter than those in the unaffected carriers(all P<0.001).Compared with the control group,affected LHON patients had a thinner retinal nerve fiber layer(RNFL),ganglion cell layer and inner plexiform layer(GCL+IPL),and total retina(all P<0.01).The retinal nerve fiber layer(RNFL)of affected patients was 38.0%thinner than that of controls while the GCL+IPL was 40.1%thinner.CONCLUSION:The foveal pit morphology shows changes in both unaffected carriers and affects patients.RNFL and GCL+IPL are thinner in affected LHON patients but not in unaffected carriers.

Leber Hereditary Optic Neuropathy in a Boy with Fibrous Boney Dysplasia

Purpose:To report a case of Leber hereditary optic neuropathy combined with fibrous boney dysplasia. Methods: Case report. Results:A 16-year-old boy presented with painless vision loss in both eyes. He had a history of a right humerus fracture and right femoral fracture surgery after an uncomplicated fall.On examination in our clinic, his visual acuity was counting fingers at 20 cm OD and counting fingers at 40 cm OS.Both pupils reacted sluggishly to light.The findings on slit-lamp examination and funduscopy after pupillary dilation were all unremarkable. Computed tomography scans demonstrated fibrous dysplasia involving the right frontal, temporal, parietal, and occipital bones but no stenosis of either optic canal. His serum alkaline phosphatase was 522 U/L (reference range: 40-150 U/L). His vision showed no improvement after intravenous methylprednisolone pulse therapy.Finally,a 11778 mitochondrial DNA mutation was detected. He still had no visual recovery after treatment with oral coenzyme Q10,vitamin B1, and citicoline. Conclusion:Fibrous dysplasia of bone may be associated with Leber hereditary optic neuropathy,possibly due to the fact that it increases local oxygen consumption. (Eye Science 2013; 28:48-50)

Complete mitochondrial DNA sequence analysis in two southern Chinese pedigrees with Leber hereditary optic neuropathy revealed secondary mutations along with the primary mutation

AIM: To investigate mitochondrial factors associated with Leber hereditary optic neuropathy (LHON) through complete sequencing and analysis of the mitochondrial genome of Chinese patients with this disease. METHODS: Two unrelated southern Chinese families with LHON and 10 matched healthy controls were recruited, and their entire mitochondrial DNA (mtDNA) was amplified and sequenced with the universal M13 primer. Then DNA sequence analysis and variation identification were performed by DNAssist and Chromas 2 software and compared with authoritative databases such as Mitomap. RESULTS: Mutational analysis of mtDNA in these two Chinese pedigrees revealed one common LHON-associated mutation, G11778A (Arg -> His), in the MT-ND4 gene. In addition, there were two secondary mutations in Pedigree 1: C34971 (Ala -> Val), and C3571T (Leu -> Phe) in the MT-ND1 gene, which have not been reported; and two secondary mutations occurred in Pedigree 2: A10398G (Thr -> Ala) in the MT-ND3 gene, and T14502C (Ile -> Val) in the MT-ND6 gene. Three polymorphisms, A73G, G94A and A263G in the mtDNA control region, were also found. CONCLUSION: Our study confirmed that the known MT-ND4* G11778A mutation is the most significant cause of LHON. The C3497T and C3571T mutations in Pedigree 1 were also both at hot-spots of MT-ND1; they may affect the respiratory chain in coordination with the primary mutation G11778A. In Pedigree 2, the two secondary mutations A10398G of MT-ND3 and T14502C of MT-ND6 may influence mitochondrial respiratory complex I, leading to the mitochondrial respiratory chain dysfunction which results in optic atrophy together with G11778A. Therefore, not only the common primary LHON mutation is responsible for the visual atrophy, but other secondary mtDNA mutations should also be considered when giving genetic counseling.

Clinical expression and mitochondrial deoxyribonucleic acid study in twins with 14484 Leber’s hereditary optic neuropathy:A case report

BACKGROUND This study aimed to explore clinical and molecular factors that cause discordance for clinical expression of Leber’s hereditary optic neuropathy(LHON)in a pair of identical twins with the 14484 point mutation.CASE SUMMARY Twin patients with the 14484 point mutation were studied for zygosity by using the Short Tandem Repeats Typing system.For the monozygotic twins,the radioactive restriction and densitometric analyses were used to quantitate the heteroplasmy level for the 14484 point mutation.The mitochondrial genome was analyzed to determine influential factors by mitochondrial deoxyribonucleic acid(DNA)sequencing,denaturing high-performance liquid chromatography and next generation sequencing.For the dizygotic twins,the nuclear DNA was analyzed.The twins with 14484 LHON were monozygotic with homoplasmy.No difference in the point mutation in mitochondrial DNA was found.No modifying genes that potentially influenced the disparity in phenotypic expression of LHON were detected in these twins.CONCLUSION This 11-year follow-up of monozygotic twins showed additional genetic modifications and epigenetic factors are possibly associated with discordance for LHON.

Retinal nerve fiber and ganglion cell layer thinning in hereditary and acquired mitochondrial optic neuropathies

Dear Editor,With interest we read the article by Teng et al[1]about a study of the retinal nerve and ganglion cell layers by means of optic coherence tomography(OCT)in 32 patients with a mitochondrial optic neuropathy(MON).Included were 20 patients with hereditary MON[Leber’s hereditary optic neuropathy(LHON)],12 patients with acquired MON[ethambutol-induced optic neuropathy(EION)],and 41 healthy controls.Retinal nerve fiber layer(RNFL)thickness was reduced in the nasal,superior,temporal,and inferior quadrants in LHON patients but only in the temporal quadrant in the EION patients.Thickness of the retinal ganglion cell layer(RGCL)was similarly reduced in LHON and EION patients.We have the following comments and concerns.

Application of optical coherence tomography in hereditary,toxic and metabolic optic neuropathies

Hereditary,metabolic and toxic optic neuropathies cause bilateral,central vision loss and therefore can result in severe impairment in visual function.Accurate,early diagnosis is critical,as nutritional and toxic optic neuropathies may be reversible if identified early,and diagnosis of hereditary optic neuropathies can prevent unnecessary invasive workup,provide prognostic information,and allow for effective genetic counseling.Optical coherence tomography(OCT)is a valuable tool that aids in the diagnosis and prognostication of optic neuropathies as it allows for quantification of changes in the retinal ganglion cells(RGCs)and retinal nerve fiber layer(RNFL)over time.We review the characteristic clinical presentations of hereditary,metabolic and toxic optic neuropathies,with an emphasis on OCT findings.

一个遗传性听神经病伴视神经萎缩家系研究

目的 研究探讨一个听神经病伴视神经萎缩家系遗传性致病原因。方法 详细询问先证者病史及家族史、进行临床相关检查确诊听神经病伴视神经萎缩,绘制该家系遗传系谱。抽取先证者(Ⅲ-7)外周血行全外显子组测序,对检出的突变进行致病性判读,对先证者妻子(Ⅲ-8)、大女儿(Ⅳ-7)、二女儿(Ⅳ-9)和儿子(Ⅳ-10)进行Sanger测序验证突变位点,并结合临床表现和检查结果进行研究。结果 该家系遗传方式为常染色体显性遗传,先证者(Ⅲ-7)19岁时出现视力下降,30岁时出现双侧感音神经性聋,言语识别率下降,其所在5代20人大家系中10人(2人已故)有类似听力及视力下降症状。先证者(Ⅲ-7)、大女儿(Ⅳ-7)和儿子(Ⅳ-10)听力学检查:纯音测听示双侧感音神经性聋,ABR双耳未引出,40 Hz相关电位(AERP)双耳均未引出,OAE部分或全部频率可引出,镫骨肌声反射阈值未引出;Ⅲ-7、Ⅳ-10眼底检查有不同程度视乳头萎缩,OCT示双眼视盘神经纤维层厚度变薄、视觉诱发电位示P100波峰时延长,确诊为遗传性听神经病伴视神经萎缩。Ⅲ-7行全外显子检测发现3号染色体有一个致病位点OPA1基因c.1334G>A(p.Arg445His,NM_015560.2)突变,一代测序结果示Ⅳ-7和Ⅳ-10也有该突变,Ⅲ-8和Ⅳ-9该位点的基因型是野生纯合型,即未发生突变。结论 OPA1基因c.1334G>A(p.Arg445His,NM_015560.2)突变位点为该家系致病突变。

Structural impairment patterns in peripapillary retinal fiber layer and retinal ganglion cell layer in mitochondrial optic neuropathies

AIM：To evaluate the structural injure patterns in peripapillary retinal fiber layer （pRNFL）, retinal ganglion cell layer （RGCL） and their correlations to visual function in various mitochondrial optic neuropathies （MON） to offer help to their differential diagnosis.METHODS：Totally 32 MON patients （60 eyes） were recruited within 6mo after clinical onsets, including 20 Leber hereditary optic neuropathy （LHON） patients （37eyes）, 12 ethambutol-induced optic neuropathy （EON）patients （23 eyes）, and 41 age-gender matched healthy controls （HC, 82 eyes）. All subjects had pRNFL and RGCL examinations with optic coherence tomography （OCT） and visual function tests.RESULTS：In the early stages of MON, the temporal pRNFL thickness decreased （66.09±22.57μm）, but increased in other quadrants, compared to HC （76.95±14.81μm）. The other quadrants remaining stable for LHON and EON patients besides the second hour sector of pRNFL thickness reduced and the temporal pRNFL decreased （56.78±15.87μm） for EON. Total macular thickness in MON reduced remarkably（279.25±18.90μm; P=0.015）, which mainly occurring in the inner circle （3 mm diameter of circle） and the nasal temporal sectors in the outer circle （5.5 mm diameter of circle）, in contrast to those in HC. RGCL thickness reduced in each sector of the macula （61.90±8.73μm; P≤0.001）. It strongly showed the correlationship of best corrected visual acuity （R=0.50, P=0.0003） and visual field injury （R=0.54,P=0.0002） in MON patients.CONCLUSION：OCT is a potential tool for detecting structural alterations in the optic nerves of various MON. Different types of MON may have different damage patterns.

视野为中心暗点的视神经病变病因分析

目的:总结并分析视野为中心暗点的视神经病变的病因和临床特点,为临床诊治提供参考。方法:回顾性病例研究。分析2018年8月至2020年3月期间,在中山大学中山眼科中心神经眼科专科门诊就诊,视野表现为中心暗点且随访1年以上的视神经病变患者的资料。患者双眼均行最佳矫正视力、眼压、裂隙灯显微镜及前置镜、频域光学相干断层扫描、视野、颅脑和眼眶核磁共振检查,静脉采血行血常规、血生化、肝肾功能、感染指标(乙肝、丙肝、梅毒、HIV及结核T-spot)检查及Leber遗传性视神经病变的线粒体DNA和OPA1基因检测。结果:共纳入20例患者,病因诊断构成为:Leber遗传性视神经病变9例(45%),显性视神经萎缩2例(10%),乙胺丁醇中毒性视神经病变6例(30%),营养性视神经病变2例(10%)和特发性脱髓鞘性视神经病变1例(5%)。遗传性视神经病变的视力预后差,特别是Leber遗传性视神经病变,78%的随访视力(≥1年)不高于0.1。伴有mt DNA或OPA1基因突变的乙胺丁醇中毒性视神经病变患者,视力预后差。结论:视野为中心暗点表现的视神经病变,主要为遗传、中毒和营养性视神经病变。遗传性视神经病变具有不完全外显率的特点,视野为中心暗点的视神经病变需行基因检测排除遗传性视神经病变。

玻璃体腔注射rAAV2-ND4对遗传性视神经病变的影响

目的 分析玻璃体腔注射重组腺相关病毒-2还原型辅酶Ⅰ脱氢酶4(rAAV2-ND4)对遗传性视神经病变(LHON)的影响。方法 采用自身对照研究,以延安大学医学院2018年1月-2022年1月60例LHON患者的左眼为对照组(n=60),给予针灸治疗;以患者的右眼为观察组(n=60),在针灸治疗的基础上在玻璃体腔内注射重组腺相关病毒-2还原型辅酶Ⅰ脱氢酶4(rAAV2-ND4)治疗。对比两组治疗前、治疗第1个月、治疗第3个月、治疗第6个月的BCVA、眼压、电生理P100波潜时、视野水平和治疗第6个月的临床疗效和并发症的异同。结果 治疗前两组的BCVA、眼压、电生理P100波潜时、视野水平比较,差异无统计学意义(P>0.05),治疗第1个月、第3个月、第6个月两组的BCVA水平均降低,且观察组均高于对照组(P<0.05);治疗第1个月、第3个月、第6个月两组的眼压、视野MS水平均升高,且观察组均高于对照组(P<0.05);治疗第1个月、第3个月、第6个月两组的电生理P100波潜时水平均降低,且观察组均低于对照组(P<0.05)。治疗第6个月观察组的临床总有效率(60.00%vs 41.67%)高于对照组(P<0.05)。治疗第6个月两组的并发症(10.00%vs 8.33%)比较,差异无统计学意义(P>0.05)。结论 玻璃体腔注射联合针灸治疗LHON能够较好地改善患者的BCVA、眼压、电生理P100波潜时、视野水平,改善临床疗效,且无明显并发症。

71例Leber遗传性视神经病变误诊分析

目的观察Leber遗传性视神经病变(LHON)的临床诊治情况,分析其误诊原因,探讨提高早期确诊率的思路。方法纳入2018年1月~2022年8月就诊于北京中医药大学东方医院眼科经线粒体脱氧核糖核酸(mtDNA)基因检查确诊为LHON的患者104例,进行问卷调查。调查内容重点围绕该病的误诊情况。调查方式除面对面交谈外,主要通过查阅专科存档病例,病历资料不全或存疑者通过电话了解补全相关内容。结果(1)基因位点突变情况:纳入的104例患者中,继发突变位点14例,存在m.11778G>A位点突变70例(67.3%);存在m.3460G>A位点突变12例(11.5%);存在m.14484T>C位点突变8例(7.7%)。(2)误诊情况:首诊误诊患者共62例,误诊率为59.6%,合并转诊后仍误诊的9例,共误诊71例,总误诊率高达68.3%。其中,71例LHON被误诊的眼病包括:视神经炎49例,视神经萎缩8例,弱视8例,屈光不正2例,中心浆液性脉络膜视网膜病变、青光眼、视疲劳各1例,1例未明确诊断。71例误诊患者从首次就诊到明确诊断时间去除极大值后,中位确诊时间为48 d,均值为(102.9±81.1)d。明确诊断的患者平均就诊次数为(2.1±0.8)次,其中明确诊断的时间最长为31年。结论应加强LHON的临床认识和诊疗程序,熟悉LHON的临床特征,以减少LHON的漏诊、误诊和误治。

1例Leber遗传性视神经病患者中医外治护理体会

本文总结1例Leber家族遗传性视神经病患者中医外治护理体会。基于中医理论指导辨证施护,采用耳穴贴压、梅花针、中药离子导入中医外治,同时配合饮食护理、情志护理等常规护理干预,有助于提高患者治疗依从性,缓解视力障碍。

线粒体tRNA^(Glu)A14693G可能是与Leber遗传性视神经病变相关的基因突变

收集了3个具有典型临床特征的中国汉族Leber遗传性视神经病变(Leber′s hereditary optic neuropathy,LHON)家系。通过对先证者和家系其他成员进行眼科临床(如视力损害程度和发病年龄)检查,发现这些家系成员中视力损害的外显率很低,经mtDNA测序分析,在tRNAGlu上发现了A14693G同质性突变位点,多态性位点分别属于东亚单体型Y1b、Y1和Y1,没有发现其他高度保守和有功能意义的突变位点。A14693G突变位于线粒体tRNAGlu高度保守区(通用位点为54位),可能导致tRNA空间结构和稳定性发生改变,继而影响tRNA的代谢,导致线粒体蛋白合成功能受损和ATP障碍,最终导致视力损害。所以,tRNAGluA14693G突变可能是与视神经病变相关的致病性线粒体突变位点。