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.

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.

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.

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.

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...

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.

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.

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)

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.

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.

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.

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.

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。

Leber遗传性视神经病变家系的线粒体基因突变分析

为探讨Leber遗传性视神经病变(Leber′shereditaryopticneuropathy,LHON)家系线粒体DNA(mtDNA)常见致病原发突变的频谱,用聚合酶链反应(polymerasechainreaction,PCR)和单链构象多态性(single strandedconformationalpolymorphism,SSCP)以及DNA测序的方法,对13个家系22位临床诊断为LHON的患者及其母系亲属21人的线粒体DNA进行检测,同时检测71例正常人作为对照。临床拟诊为LHON的13个家系中,11个家系存在mtDNA位点11778G→A突变,另2个家系存在14484位点T→C突变。说明中国LHON病人存在线粒体DNA11778或14484位点突变,其中14484位点突变在国内尚未见报道。

中国人群携带m.14484T>C突变的Leber’s遗传性视神经病变线粒体单体型及多态位点分析

线粒体ND6基因（MT-ND6）上的m.14484T＞C突变是Leb er＇s遗传性视神经病变（Leber＇s hereditary optic neuropathy,LHON）的一个原发性突变,但该突变自身不足以产生视力损伤.为研究线粒体单体型对携带该突变人群LHON发病的影响,文章对1 177例中国汉族LHON患者MT-ND6基因进行了全面系统的筛查,共筛查到67例患者携带m.14484T＞C同质性突变,在该研究群体中所占比例为5.7％.携带m.14484T＞C突变的51例家系LHON的外显率从5.6％～100.0％不等,平均外显率为21.5％.对家系中51例先证者线粒体全基因组进行分析,各表现为不同的多态性,分别属于18个东亚线粒体单体型.其中单体型A和单体型F在病例组频率均明显低于106例对照组.另外,单体型M10a在病例组中占9.8％,在对照组中未被发现,进一步发现该单体型家系LHON的平均外显率（46.13％）显著高于其他单体型家系的平均外显率,提示线粒体单体型M10a可能增加视力损伤的风险.

线粒体ND1基因T3866C突变可能是Leber’s遗传性视神经病和四肢畸形跛行相关的突变

线粒体DNA(Mitochondrial DNA,mtDNA)突变与人类许多疾病的发病机制相关。现报道1个具有典型母系遗传特征的中国人Leber’s遗传性视神经病和四肢畸形跛行的家系。该家系共5代60人,共27名母系成员,其中4人只有Leber’s遗传性视神经病症状,1人呈现四肢畸形跛行症状,4人同时具有上述两种临床症状,而其他成员无临床症状。对先证者的mtDNA全序列进行分析,发现ND1基因T3866C突变位点和43个多态位点,经系统进化树分析属于东亚单体型D4a3。MtDNAND13866位点T-C碱基的改变使ND1亚基第187位进化高度保守的异亮氨酸转变为苏氨酸,从而改变该蛋白的结构,进而影响其功能。在135名正常对照中未发现该突变。因此,线粒体ND1T3866C可能是与Leber’s遗传性视神经病和四肢畸形跛行相关的线粒体基因突变。

线粒体T12338C突变可能是与Leber遗传性视神经病变相关的突变位点

Leber遗传性视神经病变变(Leber’s hereditary optic neuropathy,LHON)是一种与线粒体DNA(Mito-chondrial DNA,mtDNA)突变相关的母系遗传性眼科疾病。文章报道了两例具有典型LHON临床、分子遗传特征的中国汉族家系。首先通过对家系先证者和其他成员进行眼科相关检查,发现两个家系成员中视力都仅有先证者一人损害严重,即外显率很低。经常规的方法对母系成员进行mtDNA测序及相关软件分析,结果发现携带ND4 G11696A和ND5 T12338C同质性突变位点,多态性变异位点均属于东亚单体型F2。线粒体DNA ND4 G11696A是一个已知的与LHON相关的突变位点,而T12338C位于线粒体氧化磷酸化复合体I亚基ND5的第2个碱基,该突变使起始密码子由蛋氨酸转变成苏氨酸,并且紧连tRNALeu(CUN)的3′末端。这可能影响tRNA Leu(CUN)空间结构和稳定性发生改变,以及起始密码子改变导致线粒体ND5蛋白合成功能受损和ATP障碍,最终导致需求能量高的视神经受损和视力损害。因此,线粒体ND4 G11696A和ND5 T12338C突变可能协同作用Leber遗传性视神经病变的发生,是与LHON相关的mtDNA突变位点,但外显率很低说明突变本身不足以造成LHON的表型表达,提示其他修饰因子(核修饰基因、环境等)可能对这两个家系发病起协同作用。