进行性肌阵挛癫一家系临床与遗传学特征分析

目的 研究一个进行性肌阵挛癫(癎)家系的临床特点、遗传性特征并复习文献.方法 搜集并整理一个进行性肌阵挛癫(癎)家系患者临床表现、辅助检查及影像学资料,分析其临床特点和遗传性特征.结果 该家系呈母系遗传,先证者表现为进行性肌阵挛癫(癎)发作,同时伴有近端肌无力、肌肉萎缩、腱反射减弱.肌电图提示肌源性改变,头颅磁共振提示皮层萎缩,该家系中除先证者外其他患者均在发病后6～8 a死亡,预后差.结论 该进行性肌阵挛癫(癎)家系很可能为线粒体脑肌病的肌阵挛癫(癎)伴破碎红细胞纤维(MERRF)型,确诊有待进一步的肌肉活检和基因诊断.     

肌阵挛癫痫伴破碎红纤维的分子生物学研究进展

肌阵挛癫痫伴破碎红纤维 (MERRF)是最早认识的由点突变造成的伴有破碎红纤维 (RRF)的多系统疾病 ,是三个主要的线粒体脑肌病之一 ,本文就MERRF的分子致病机制进行综述 ,并介绍了基因诊断及遗传咨询等方面的研究进展。     

进行性肌阵挛癫痫的治疗进展

进行性肌阵挛癫痫(PMEs)是一组罕见的遗传性疾病。常见的临床表现包括动作性肌阵挛常伴全面强直阵挛发作、认知障碍以及其他局灶性神经功能缺损等。PMEs对抗癫痫发作药物的反应一般较差, 总体预后差。可以导致PMEs的疾病包括Unverricht-Lundborg病、Lafora病、神经元蜡样脂褐质沉积症、肌阵挛性癫痫伴破碎样红纤维综合征、唾液酸沉积症、齿状核红核苍白球路易体萎缩症等。目前PMEs的治疗包括药物治疗、神经调控治疗、饮食治疗、抗炎和免疫调节治疗、酶替代治疗和基因治疗等。文中对目前已知的PMEs治疗进行综述, 为更好地研究和探索PMEs的治疗方法提供思路。     

良性成人家族性肌阵挛癫痫

<正>良性成人家族性肌阵挛癫痫(benign adult familial myoclonic epilepsy,BAFME)是一种于成年期发病的常染色体显性遗传、以皮质震颤、肌阵挛伴或不伴癫痫发作为主要临床表现的少见癫痫综合征。Inazuki等[1]于1990年首次报道了1例具有以上特点的日本家系,同年Ikeda等[2]发现这种震颤为皮质源性,自此开启了对BAFME的逐步深入研究。迄今为止,全世界已有     

中国10个全面性癫痫伴热性惊厥附加症家系的临床特征分析

目的探讨中国全面性癫痫伴热性惊厥附加症(generalized epilepsy with febrile seizure plus,GEFS+)家系的临床特征。方法通过门诊就诊、个人访视、电话等方式,对10个GEFS+家系所有成员进行详细临床资料收集,包括家系图谱、有无发作、发作形式以及检查结果等。结果10个家系共有140名成员接受了调查(其中3名去世,由亲属提供病史),发现受累者80例,其中74例符合GEFS+临床发作谱,2例为特发性全面性癫痫,4例不能明确分类。其中有两个家系较为特殊(家系I和家系H),2个家系受累者绝大部分仅表现为热性惊厥(febrile seizure,FS),每个家系仅有先症者1人表现为热性惊厥附加症(febrile seizure plus,FS+)。此外还发现3例FS+伴局灶性发作,2例为FS+伴儿童良性癫痫伴中央颞部棘波,1例为FS+伴颞叶癫痫。结论GEFS+是一种常见的、儿童时期起病的遗传性癫痫综合征,GEFS+最常见的表型为FS和FS+,其次是FS+伴局灶性发作、FS伴IGE、FS+伴失神发作以及FS+伴肌阵挛发作,我们的10个GEFS+家系中未发现FS+伴失张力发作、肌阵挛站立不能性癫痫和婴儿严重肌阵挛癫痫,说明这些表型为临床少见表型;此外我们还发现了GEFS+合并IGE以及在FS遗传背景上仅个别患者为FS+的较特殊家系,这些将进一步扩展GEFS+的概念。     

肌阵挛性小脑协调不能一家系临床及神经影像学特点

目的 通过报道一个肌阵挛性小脑协调不能患者家系,探讨其临床、遗传学及神经影像学特点.方法 对该家系中的先证者进行临床、神经影像学、脑电图、皮肤肌肉病理学及血液学检查,对家系中的其余该病患者进行追踪,绘出家系图谱.结果 该患者家族27位成员中共有肌阵挛性小脑协调不能患者6例,所有患者均有不同程度的肌阵挛、癫痫、进行性小脑共济失调表现.先证者颅脑MRI可见全脑萎缩,其中小脑和皮质萎缩略重.脑白质可见长T1长T2异常信号,T2FLAIR像呈高信号.脑电图见棘慢波、多棘慢波.皮肤肌肉病理活体组织检查未见异常.结论 肌阵挛性小脑协调不能为常染色体显性遗传疾病,临床主要表现为肌阵挛、进行性小脑共济失调和癫痫.颅脑磁共振可表现为脑皮质及小脑萎缩、脑白质异常信号,脑电图棘慢波.诊断主要根据家族遗传史、典型临床表现及颅脑MRI和脑电图特点.     

青少年肌阵挛性癫痫的研究动态

青少年肌阵挛性癫痫(juvenile myoclonic epilepsy,JME)是一种特发性全身性癫痫综合征,以肌阵挛发作为突出表现.Herpin于1867年首次描述了1个JME病例,该病例为一13岁的男孩,开始表现为上身抽搐,3个月后进展为"完全的癫痫发作".     

肌阵挛与肌阵挛癫痫

肌阵挛是中枢神经系统所致突然、短暂、电击状(shock like)不随意运动。肌阵挛癫痫定义尚有争议,目前认为可能是涵盖癫痫的电临床意义,累及下行的神经元,此神经元的扩展或颞叶扩充能扳击为明显的痫性活动。肌阵挛可能是多种癫痫综合征的一部分(如青少年肌阵挛、全面强直-阵挛或进行性肌阵挛癫痫),也可能是单独发作表现(如良性肌阵挛癫痫),或是多种癫痫类型之一(如肌阵挛性-不稳定性癫痫)。肌阵挛癫痫分为皮层性肌阵挛、丘脑-皮层性肌阵挛、皮层反射性肌阵挛、阴性肌阵挛、良性家族性皮质性肌阵挛震颤癫痫、进行性肌阵挛癫痫、青少年肌阵挛癫痫。一般传统抗癫痫药物,除丙戊酸、氯硝基安定、苯巴比妥外,其他抗癫痫药物均无效。新型抗癫痫药物已证实左乙拉西坦、托吡酯、唑尼沙胺、吡拉西坦及吡仑帕奈有效,但对不同类型肌阵挛癫痫治疗效果有差异。     

进行性肌阵挛癫(癎)一家系临床与遗传学特征分析

目的 研究一个进行性肌阵挛癫(癎)家系的临床特点、遗传性特征并复习文献.方法 搜集并整理一个进行性肌阵挛癫(癎)家系患者临床表现、辅助检查及影像学资料,分析其临床特点和遗传性特征.结果 该家系呈母系遗传,先证者表现为进行性肌阵挛癫(癎)发作,同时伴有近端肌无力、肌肉萎缩、腱反射减弱.肌电图提示肌源性改变,头颅磁共振提示...     

8例家族性皮质肌阵挛震颤性癫痫临床特点分析

目的分析家族性皮质肌阵挛震颤性癫痫(FCMTE)的临床特点。方法对8例FCMTE患者的临床资料进行回顾性分析,总结家系的临床特点、遗传特征。结果 8例FCMTE患者,连续3代发病,男女均受累,均30岁以后起病,先后出现震颤、全面强直-阵挛发作。其中,5例伴头痛,6例有肢体震颤,4例有情绪焦虑,1例有共济失调症状。8例均于30岁以后癫痫发作,呈强直-阵挛发作。4例刺激左右正中神经记录的躯体感觉诱发电位(SEPs)可见巨大电位,未见C-反射。结论 FCMTE呈常染色体显性遗传,均发生于成人,表现为四肢末端细微震颤、强直-阵挛性癫痫发作,光刺激、情绪激动或惊吓时可诱发。服抗癫痫药有效,服用β受体阻滞剂或饮酒无效,为非进展性病程。神经电生理检查提示肌阵挛或震颤来源于大脑皮质。     

Gene dosage effect in one family with myoclonic epilepsy and ragged-red fibers (MERRF)

Objectives - We analyzed the percentage of mitochondrial DNA (mtDNA) heteroplasmy in blood samples of 13 individuals belonging to a three family generation of myoclonic epilepsy with ragged-red fibers (MERRF) and compared the 5 affected patients and the 8 unaffected relatives. Material and methods - DNA was extracted from blood and muscle of the proband and from blood of 12 maternal relatives. A PCR restriction analysis method was used to detect the mutation. Results - The proband had the complete MERRF phenotype. The phenotype in three other individuals in the maternal lineage was consistent with the MERRF syndrome. The remaining were asymptomatic. The np 8344 mutation was observed in muscle and blood of the proband, and in blood from every one of 12 maternal relatives, ranging from 44% to 83% of mutated genomes. Symptomatic individuals had higher levels ( P < 0.001) of mutated mtDNA than asymptomatic maternal relatives. However, high proportions of mutant genomes (up to 63%) were found in asymptomatic relatives. Conclusions - Although there seems to be a gene dosage effect in MERRF, we found no absolute relationship between the relative proportion of mutant genomes in blood and clinical severity. Factors other than gene dosage in blood may account for the differences in clinical phenotype.     

Myoclonic epilepsy with ragged-red fibers (MERRF) syndrome: Report of a Chinese family with mitochondrial DNA point mutation in tRNALys gene

We report myoclonic epilepsy with ragged-red fibers (MERRF) syndrome in a Chinese family with confirmed mitochondrial DNA point mutation. Six members of the family including the grandmother, two siblings, and three grandchildren were affected. Among them, action myoclonus was seen in five; short stature, muscle weakness, and mental retardation in four; lactic acidosis, hearing impairment, and ataxia in two; and seizures in one. Muscle biopsy from two affected siblings revealed ragged-red fibers and abundant subsarcolemmal mitochondria with paracrystalline inclusions. Pedigree analysis suggests a maternal transmission. Analysis of mitochondrial DNA showed a point mutation from A to G at the 8344th nucleotide position located in the tRNA_Lys gene. To our knowledge, this is the first report of MERRF syndrome with such genetic defect from a Chinese family. The present and previous reports support the notion that mitochondrial DNA point mutation at the 8344th nucleotide position is the most common cause of MERRF syndrome. © 1994 John Wiley & Sons, Inc.     

The T-C(8356) mitochondrial DNA mutation in a Japanese family

A rare point mutation at nucleotide position 8356 in the transfer RNA gene in mitochondrial DNA was found in a Japanese family. Our proband had migraine and dementia associated with lactic acidosis in addition to myoclonic epilepsy with ataxia and ragged-red fibres in a muscle biopsy specimen consistent with the clinical characteristics of myoclonic epilepsy with ragged-red fibres (MERRF). His mother, who had the same point mutation, also had migraine but without myoclonus or ataxia. His aunt, who had the same point mutation and migraine, developed diabetes mellitus, encephalomyopathy and several stroke-like episodes associated with lactic acidosis (MELAS). This is the third family with the rare mutation seen in American and Italian families. The mutation may not be specific to Caucasians, and is probably closely related to the MERRF/MELAS overlap syndrome.     

The mitochondrial DNA A8344G mutation in leigh syndrome revealed by analysis in paraffin-embedded sections: Revisiting the past

In 1975, we presented the results of a study on a family with a constellation of features that included a chronic spinocerebellar syndrome, neuropathologically proven Leigh syndrome, and sudden death in infancy or childhood affecting several members over three generations. Inheritance was thought to be autosomal dominant. Twenty years later, we reinterpreted the inheritance pattern as maternal. Mitochondrial DNA (mtDNA) extracted from paraffin-embedded brain samples from the proband revealed the A8344G myoclonic epilepsy and ragged-red fiber (MERRF) mutation as the molecular basis for this multifaceted neurological syndrome. This re-evaluation of archival material is an instructive example of “medical archeopathology”.     

G8363A mutation in the mitochondrial DNA transfer ribonucleic acidLys gene: another cause of Leigh syndrome

We identified a G-->A transition at nt-8363 in the mitochondrial DNA transfer ribonucleic acidLys gene in blood and muscle from a 13-month-old girl who had clinical and neuroradiologic evidence of Leigh syndrome and died at age 27 months. The mutation was less abundant in the same tissues from the patient's mother, who developed myoclonus epilepsy with ragged red fibers (MERRF) in her late 20s. In both mother and daughter, muscle histochemistry showed ragged red and cytochrome c oxidase-negative fibers and biochemical analysis showed partial defects of multiple respiratory-chain enzymes. A maternal half-sister of the proband had died at 2.5 years of age from neuropathologically proven Leigh syndrome. The G8363A mutation, which previously had been associated with cardiomyopathy and hearing loss, MERRF, and multiple lipomas, also should be included in the differential diagnosis of maternally inherited Leigh syndrome.     

Use of single strand conformation polymorphism analysis to detect point mutations in human mitochondrial DNA.

Myoclonus epilepsy with ragged-red fibers (MERRF) has been shown to be associated with a specific point mutation at the nucleotide 8344 in the tRNA(Lys) gene of mitochondrial DNA (mtDNA). We screened 6 patients with clinically diagnosed MERRF and 1 patient with ocular myopathy for point mutations in the tRNA(Lys) gene, using single strand conformation polymorphism (SSCP) analysis, which can detect even a 1-basepair difference between 2 DNA sequences. Using SSCP and consequent DNA sequencing, we identified the known MERRF mutation in 4 out of 6 MERRF patients, as well as in 1 patient with a new clinical phenotype associated with this mutation: progressive external ophthalmoplegia, muscle weakness and a lipoma, but no myoclonus or epilepsy. Two of the patients with clinical MERRF had neither the MERRF-mutation nor any other mutations in the tRNA(Lys) gene. Using SSCP analysis, we also detected a new polymorphism in 1 patient. Thus, SSCP analysis can be applied to search effectively and rapidly for point mutations or polymorphisms in mitochondrial DNA.     

线粒体脑肌病伴高乳酸血症和脑卒中样发作综合征一家系临床特征及线粒体基因A3243G位点点突变异质性水平

目的 调查1个疑似患有母系遗传性线粒体脑肌病伴高乳酸血症和脑卒中样发作(MELAS)综合征家系的临床表现、生物化学检测数据和影像学资料,并探索其与血细胞线粒体基因突变异质性水平的关联性.方法 收集先证者和11位其母系家系成员的一般情况、抽搐及脑卒中样发作等病史,检测家系成员的血常规和运动前后血浆乳酸水平等生化指标,并做头颅磁共振检查.用聚合酶链反应(PCR)-限制性内切酶片段长度多态和DNA测序法检测其成员是否存在线粒体基因组A3243G点突变,并用荧光实时定量PCR定量该突变的水平.结果 该家系部分成员存在抽搐、脑卒中样发作和高乳酸血症等MELAS综合征典型症状,以及身材矮小、运动不耐受和发热、偏头痛等非典型症状.发作期头颅磁共振成像符合MELAS综合征的典型特点,且普遍存在小脑萎缩.母系亲属均存在线粒体基因的A3243G位点点突变,突变异质性水平越高,症状越典型且严重.结论 该调查家系确诊母系遗传性MELAS综合征,其致病基因为线粒体A3243G点突变.外周血血细胞线粒体基因突变异质性水平与亲缘关系、抽搐早现性和血乳酸值等临床表型存在相关性.     

Clinical and genetic features in two families with MELAS and the T3271C mutation in mitochondrial DNA

The majority of patients with MELAS (mitochondrial encephalomyopathy, lactic acidosis, and strokelike episodes) have the A3243G point mutation. The much rarer T3271C mutation has been reported predominantly in Japanese subjects. Our objective was to better define the clinical phenotype and mutation load in patients with MELAS and the T3271C mutation in mitochondrial DNA. We present clinical and molecular genetic data in two pedigrees with the T3271C mutation. The age at onset was 8 years in one proband and 14 years in the other. Both patients had migrainelike headache, seizures, and strokelike episodes. Mutation loads were quantified in multiple tissues from the patients and from family members by polymerase chain reaction-restriction fragment length polymorphism analysis. The symptoms in both probands were typical of MELAS, and, contrary to previous reports, onset was early. Hearing loss was less common than in typical MELAS, and ragged red fibers were absent. The proportion of mutant genomes was consistently and markedly greater in DNA from urinary sediment than from blood. In the mother of one proband, mutant genomes were detected only in DNA from hair follicles and cheek mucosa The phenotype of patients with the T3271C mutation might not be as distinct as that of the A3243G mutation, as previously described. Our data also suggest that urine is a better source of DNA than blood for diagnosis and that multiple tissues should be studied in maternal relatives, especially when the mutation cannot be detected in blood.     

MELAS syndrome with mitochondrial tRNA(Leu(UUR)) gene mutation in a Chinese family.

The clinical features of a patient in a Chinese family with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS syndrome) are reported. The study revealed that hearing and visual impairments and miscarriages may be early clinical presentations in MELAS. A heteroplasmic A to G transition in the tRNA(Leu(UUR)) gene was noted at the nucleotide pair 3243 in the mitochondrial DNA of muscle, blood, and hair follicles of the proband and his maternal relatives. Quantitative analysis of the mutated mitochondrial DNA revealed variable proportions in different tissues and subjects of maternal lineage in the family. Muscle tissue contained a higher proportion of the mutant mitochondria than other tissues examined. The function of the reproductive system of the proband seems to be impaired. In one clinically healthy sibling, the 3243rd point mutation was found in sperm mitochondrial DNA, although sperm motility was not affected. It seems that biochemical defects in mitochondrial respiration and oxidative phosphorylation are tissue specific expressions of the 3243rd point mutation in the mitochondrial DNA of the affected target tissues.     

Unusual presentations of patients with the mitochondrial MERRF mutation A8344G

MERRF is typically characterized by myoclonus, generalized seizures and ragged-red fibers in muscular biopsy. We report a family (harbouring the A8344G mutation) with a late onset of the disease and an uncommon clinical manifestation, including episodes of reversible respiratory failure, the presence of ophthalmoplegia, and the absence of seizures and myoclonus in most subjects. We conducted histochemical, biochemical and molecular genetic studies. Mutation analysis revealed that the level of mutated mitochondrial DNA (mtDNA) was above 80% in the skeletal muscle of all siblings. Nevertheless, one severely affected individual did neither present cytochrome c oxidase-negative fibers nor ragged-red fibers in the skeletal muscle biopsy. These data extend the phenotypic range associated with the MERRF syndrome. We suggest that the analysis of mtDNA could be of importance in many cases of unclear multisystem disorders in later life.