肌营养不良症致病基因编码产物检测的初步研究

目的对导致肌营养不良症的基因编码产物进行检测，从分子水平为临床诊断和分型提供依据。方法应用蛋白质印迹技术对临床诊断为肌营养不良症的患者进行抗肌营养不良蛋白、αｓａｒｃｏｇｌｙｃａｎ和γｓａｒｃｏｇｌｙｃａｎ的研究。结果首次在中国人群中检测出由于α和γｓａｒｃｏｇｌｙｃａｎ缺陷而致的常染色体连锁遗传性肢带型肌营养不良症２例，检测出由于抗肌营养不良蛋白缺陷而致的迪谢内肌营养不良症２例。结论肌营养不良症在临床症状、遗传模式等方面具有极不均一的特点。直接检测致病基因的编码产物不仅为临床诊断和分类提供了依据，也为进一步研究致病基因，阐明该病的病理机制奠定了基础     

应用免疫印迹法诊断肢带型肌营养不良2A型

目的 应用免疫印迹法(Western blot)诊断肢带型肌营养不良2A型(LGMD2A)患者并与LGMD2B型相鉴别.方法 收集我院诊治的4例LGMD2型患者的临床、病理及生化检验资料.取肌肉活体组织行组织化学和免疫组织化学染色,用Western blot分析dysferlin蛋白及calpain-3蛋白的表达.结果 LGMD2A与2B型患者的临床症状相似;免疫组织化学染色显示所有患者均出现不同程度的dysferlin缺失.但Western blot揭示:LGMD2A型患者calpain-3蛋白完全缺失,dysferlin蛋白部分缺失;而2B型患者则相反.结论 用Western blot检测calpain-3蛋白可在dysfedin蛋白表达缺失的LGMD患者中鉴别出2A型患者,该方法对临床辅助诊断LGMD2A有很好的价值.     

眼咽型肌营养不良症一家系临床及分子生物学特征分析

目的 总结一眼咽型肌营养不良症(OPMD)家系的临床及分子生物学特征.方法 收集云南省楚雄彝族自治州的一OPMD家系的临床资料,并对其中6位家族成员行外周静脉血基因组DNA分离,通过聚合酶链反应(PCR)、TA克隆和Sanger测序,检测PABPN1基因变异特点.结果 该OPMD家系中4位成员均于50岁后发病,以眼睑下...     

眼咽型肌营养不良汉族六家系的临床和遗传学特点

目的 初步总结我国汉族眼咽型肌营养不良(OPMD)患者的临床和多腺苷酸结合蛋白核1(PABPN1)基因改变特点.方法 6个OPMD家系共28例患者,男性13例,女性15例,发病年龄32～70岁,平均发病年龄49.7岁.在可确定首发症状的患者中,以吞咽困难或构音障碍首发的13例、眼睑下垂首发的4例、双下肢无力首发的1例.经过3～20年均出现眼睑下垂、吞咽困难和构音障碍,其中7例出现四肢近端无力.对6例先证者做肌肉活体组织检查,标本进行常规组织病理和电镜检查.对6个家系的先证者以及部分家庭成员进行PABPN1基因检查,并对6例先证者进行单体型分析.结果 6例先证者的肌肉活体组织检查均发现肌纤维直径轻度变异加大伴随肌纤维内镶边空泡形成,4例患者经电镜检查发现OPMD典型的核内栅栏样丝状包涵体.3个家系的PABPN1基因型为(GCG)9,另外3个家系的基因型分别为(GCG)6(GCA)1(GCG)3、(GCG)10和(GCG)8.2个携带(GCG)9突变的家系存在rs2239579(C)-(GCG)9-SNP2622(C)的单倍体型.结论 吞咽异常和眼睑下垂均是我国汉族OPMD患者的首发症状.肌纤维出现镶边空泡以及核内包涵体是我国患者的常见病理改变.PABPN1基因的(GCG)异常扩增和(GCA)插入突变均出现在我国患者,起源具有多源性.携带(GCG)9突变的部分家系可能来自共同祖先.     

假肥大型肌营养不良患者dystrophin基因缺失断裂点的分子结构特点

目的分析假肥大型肌营养不良患者dystrophin基因缺失断裂点的分子结构特点，探讨dystrophin基因缺失的发生机制。方法以PCR步移法定位2例DMD患者基因断裂位点，克隆其缺失连接片段并测序，通过Pubmed文献检索获取既往55例缺失连接片段序列资料，对以上57例缺失连接片段5′端和3′端断裂点两侧的序列进行重复序列、基质附着区、TTTAAA序列以及基因缺失后修复方式的分析。结果57例缺失连接片段中40．4％断裂点位于重复序列，其中主要是L1元件和Alu元件；36．3％断裂点在邻近基质附着区5kb之内的区域；15．0％断裂点两侧50bp的范围内发现有，TTTAAA序列；基因缺失后修复的方式仅1例通过Alu元件同源连接，其余56例通过非同源末端连接进行修复，非同源末端连接以形成1～4bp的微小同源序列为主。结论重复序列、基质附着区、TTTAAA序列以及非同源末端连接修复机制均在一定程度上参与dystrophin基因的断裂重组。dystrophin基因缺失可能是由以上多种因素的综合作用所导致，染色体的物理结构可能在基因缺失中起主要作用。     

眼咽型肌营养不良一家系临床、电生理、病理及基因分析

目的 报道1个出现神经源性骨骼肌损害的眼咽型肌营养不良(OPMD)家系的临床、骨骼肌病理和基因改变特点.方法 先证者为60岁男性,50岁时出现双下肢近端无力,53岁出现吞咽困难和构音障碍,57岁出现双眼睑下垂和眼球突出.肌酸激酶轻度增加,四肢肌电图为神经源性损伤,周围神经传导速度下降20%～43%.家系3代中除先证者外尚有5例在45岁后出现吞咽困难,4～20年后出现眼睑下垂,其中3例有肢体无力.对先证者左肱二头肌做肌肉活体组织检查,标本进行组织学、酶组织化学以及免疫组织化学染色(以抗结蛋白和泛素蛋白抗体作为一抗)和超微病理检查.对先证者和家系中另外18人进行多腺苷酸结合蛋白(PABPN1)基因检查.结果 先证者肌纤维内出现镶边空泡伴泛素阳性沉积物和成组分布的小角状萎缩肌纤维,个别肌纤维出现再生改变伴随结蛋白沉积,可见细胞色素C氧化酶阴性肌纤维.电镜检查发现约3%的肌纤维核内存在栅栏样细丝包涵体.先证者和另外11名家系成员的PABPN1基因存在(GCG)9异常扩增.结论 杂合(GCG).异常扩增性OPMD可先出现咽喉肌无力,伴随脱髓鞘性神经病.我国患者也存在肌纤维核内包涵体.     

肌电图和靶基因检测在强直性肌营养不良中的诊断价值

目的探讨强直性肌营养不良的临床特征,评价肌电图和靶基因检测方法在诊断中的应用价值。方法回顾性分析来自4个不同家系的6例患者的临床特点、肌电图和靶基因检测结果。结果该组6例患者均存在不同程度肌强直、肌无力和肌萎缩及多系统受累等临床表现。肌电图显示,肌源性损害伴肌强直放电阳性率为100%;神经传导(NCS)提示,3例有部分运动神经CMAP波幅降低,余均正常。靶基因检测提示,该组患者的强直性肌营养不良蛋白激酶(DMPK)基因3′非翻译区(3′-UTR)的CTG重复异常扩增率为100%,均50次;锌指蛋白9(ZNF9)基因的第1个内含子中CCTG重复扩增均正常。结论在强直性肌营养不良的诊断中,阳性家族史、典型的临床特征是诊断的基础,肌电图是诊断筛选的首选方法,特别是在强直性肌营养不良1型中阳性率更高,靶基因分析是诊断和分型的金标准。[国际神经病学神经外科学杂志, 2021, 48(2):120-125]     

肢带型肌营养不良2B型与多发性肌炎的临床及病理鉴别诊断

目的 分析肢带型肌营养不良2B型(LGMD2B)与多发性肌炎(PM)的临床、病理诊断与鉴别诊断要点.方法 对8例首诊为PM,再诊时高度怀疑LGMD2B的患者做开放式骨骼肌活体组织检查,行组织化学及抗dysferlin、dystrophins、sarcoglycans、MHC-Ⅰ、CD8单克隆抗体免疫组织化学染色,与4例PM进行临床、病理对比分析.结果 (1)组织化学染色2组患者均呈不同程度的肌纤维变性、坏死,炎细胞浸润;临床可疑LGMD2B患者dystrophins、sarcoglycans蛋白表达正常,dysferlin蛋白表达缺失,MHC-Ⅰ弱或阴性表达,少数炎细胞CD8阳性表达,因此确诊为LGMD2B;4例PM患者肌纤维膜上dysferlin蛋白表达正常,MHC-Ⅰ在肌纤维膜及炎细胞浸润区呈强阳性表达,部分炎细胞CD8阳性表达.(2)LGMD2B与PM临床均表现为近端肌无力,血肌酸激酶显著增高,肌电图呈肌源性异常.LGMD2B肌痛不明显,红细胞沉降率、C反应蛋白正常,有别于PM.结论 LGMD2B与PM在临床、骨骼肌组织化学染色病理上相似,易误诊;LGMD2B患者dysferlin蛋白表达缺失及PM患者的MHC-Ⅰ、CD8强阳性表达可作为两者诊断与鉴别诊断的重要方法.     

肢带型肌营养不良2B型与多发性肌炎的临床及病理鉴别诊断

Objective To diagnose and differentially diagnose limb-girdle muscular dystrophy type 2B(LGMD2B)and polymyositis (PM) based on clinical and pathological characteristics. Methods Muscle biopsics were obtained from 8 patients suspected with LGMD2B who were initially diagnosed with PM.The clinical and pathological data from 8 cases of LGMD2B and 4 cases of PM by using histo-and immunohistochemistry with anti-dysferlin,dystrophins,sarcoglycans,MHC-Ⅰ,CD8 monoclonal antibodies were compared.Results (1) LGMD2B and PM shared similar pathological presentations including muscle fibet degeneration and necrosis in various degree,proliferation of connective tissue,and inflammatory cell infiltration.Normal stains of dystrophins and sarcoglycans were observed.whereas absent or very faint staining of dysfedin observed in muscle biopsies of 8 patients confirmed the diagnosis of LGMD2B.while normal stains of dysferlin on sarcolemma were observed in the 4 cases of PM.MHC-Ⅰ was weakly expressed or absent in LGMD2B.while strongly expressed on sarcolemma in PM and the infiltration area of inflammation cells.The expression of CD8 on a few inflammatory cells were positive in LGMD2B.while some inflammatory cells were positive in PM.(2)Both LGMD2B and PM shared similar presentation,including proximal muscle weakness,remarkable elevation of CK,myopathic changes in electromyography.Patients with LGMD2B did not complain of apparent muscle pain.and their erythrocyte sedimentation rate and Creactive protein were in normal range.which could be used as marker to differentiate from patients with PM.Conclusions Clinically and pathologically LGMD2B and PM are presented similarly and likely to be misdiagnosed.The absence of dysferlin in LGMD2B and high expression of MHC-Ⅰ and CD8 in PM are the key index of the diagnosis and differential diagnosis between LGMD2B and PM.     

The Fukuyama congenital muscular dystrophy story

Fukuyama congenital muscular dystrophy is one of the most common autosomal recessive disorders in the Japanese population, characterized by congenital muscular dystrophy in combination with cortical dysgenesis (micropolygyria). Recently, we have identified the gene responsible for fukuyama congenital muscular dystrophy on 9q31, which encodes a novel 461-amino-acid protein termed fukutin. Most Fukuyama congenital muscular dystrophy-bearing chromosomes are derived from a single ancestral founder (87%), and a 3 kb-retrotransposal insertion into the 3' untranslated region of this gene was found to be a founder mutation. Two independent point mutations causing premature termination confirmed that that this gene is responsible for Fukuyama congenital muscular dystrophy. Fukuyama congenital muscular dystrophy is the first human disease to be caused by an ancient retrotransposal integration. Fukutin contains an amino-terminal signal sequence, which together with results from transfection experiments suggests that it is an extracellular protein. Discovery of the Fukuyama congenital muscular dystrophy gene represents an important step toward greater understanding of the pathogenesis of muscular dystrophies and also of normal brain development.     

Vascular alterations in Fukuyama type congenital muscular dystrophy

Blood vessels in muscle biopsy specimens from 6 Fukuyama type congenital muscular dystrophy (FCMD) patients were examined by electron microscopy and compared with ones in non-diagnostic biopsy specimens from age-matched controls and patients with childhood neuromuscular disorders. The most striking feature was the blister-like swelling of vascular endothelial cells in the biopsied muscle specimens from 5 of the 6 patients with FCMD. Morphometric analysis of capillaries in biopsied muscles showed the extremely greater capillary, endothelial and pericyte areas in the FCMD patients than in controls. These phenomena are quite similar to those found in Duchenne muscular dystrophy (DMD) at the preclinical stage and suggest an as yet undetermined process in blood vessels in FCMD as well as DMD. An immunohistochemical study involving dystrophin antibodies showed positive staining in FCMD.     

Ocular findings in Fukuyama type congenital muscular dystrophy

In Fukuyama type congenital muscular dystrophy (FCMD), congenital muscular dystrophy and anomalies of the central nervous system are regarded as the major features, but the existence of ocular lesions has hardly been recognized as being important. In the present study, close ophthalmologic examinations were performed on 11 patients with FCMD, and we found myopia, weakness of the orbicularis oculi, congenital nystagmus, cortical blindness, optic atrophy, chorioretinal degeneration, etc. In particular, the chorioretinal degeneration observed in the ocular fundus was considered to be specific to FCMD. It is thought that these ocular lesions or changes are caused by the same mechanism as that involved in the central nervous system anomalies.     

Renal dysfunction is rare in Fukuyama congenital muscular dystrophy

Background

The leading cause of death in patients with Fukuyama congenital muscular dystrophy (FCMD) is congestive heart failure or respiratory dysfunction, which is same as that in Duchenne muscular dystrophy (DMD). Recent studies reported that renal dysfunction is a common complication and an increasing cause of death in advanced DMD. It can be attributable to circulatory instability or inappropriate use of drugs for treating cardiac dysfunction.

Fukuyama congenital muscular dystrophy in two Australian female siblings

The clinical course of two female siblings with congenital muscular dystrophy is briefly described, and includes congenital cerebral malformations consisting of pachygyria, polymicrogyria and white matter abnormalities. The first sibling died in infancy; the second is now 18 years of age. The changes found at autopsy in the first sibling are identical to MRI changes in the surviving sibling.     

Epilepsy in patients with advanced Fukuyama congenital muscular dystrophy

BackgroundRecent advances in respiratory management have improved survival for patients with Fukuyama congenital muscular dystrophy (FCMD), characterized by congenital muscular dystrophy and brain malformation. Previous studies reported that more than half of patients exhibit seizures in childhood. However, little is known about epilepsy after childhood.MethodsTo elucidate the long-term clinical course of epilepsy, we retrospectively reviewed all medical records in nine patients (6 males, mean age 20.7 years) with FCMD diagnosed between 1981 and 2019.ResultsThe follow-up periods ranged from 6 to 30 years (mean 18.4 years). A total of 75 EEG recordings were available from nine patients. In some patients, EEGs were normal during early childhood but tended to show paroxysmal discharges with age. Overall, epileptic seizures were observed in six patients. Except for one presenting with afebrile seizure at one year of age, the remaining five patients developed epilepsy between 13 and 22 years of age. The most common seizure type was focal impaired awareness seizure. After adolescence, four patients exhibited status epilepticus. Their convulsive movements of the seizures became less prominent with progression of the disease. At the last evaluation, most patients (5/6) had uncontrolled seizures.ConclusionsDespite presence of distinct brain malformation, epileptic seizures may develop after childhood in FCMD patients. Our experience suggests that clinicians should be careful not to overlook epileptic seizures, especially in advanced-stage patients who had profound muscle weakness.     

Fukuyama type congenital muscular dystrophy in a Turkish child

Congenital muscular dystrophy (CMD) is a heterogeneous group of disorders which is associated with more or less degrees of cerebral involvement. There are four separate entities within CMD nosology. Among these Fukuyama's CMD (FCMD) is highly prevalent in Japan, whereas the classic form with normal or subnormal intelligence, also known as the occidental type, covers the vast majority of cases in the West. We report a case of FCMD seen in a Turkish child.     

Diaphragm muscle pathology in Fukuyama type congenital muscular dystrophy

The diaphragm muscle pathology in four patients with Fukuyama type congenital progressive muscular dystrophy (FCMD) was reported. In the diaphragm muscle fibers of three patients aged more than 14 years exhibiting chronic respiratory failure, a lot of electron dense lesions, which varied in size but did not extend over the whole length of the muscle fibers, and a marked increase in mitochondria were observed as well as the dystrophic changes. The dense lesions, consisting of electron dense fibrillary material comparable to Z-band materials in electron density, seemed to be due to Z-band disruption leading to streaming and/or large aggregations of Z-band materials. No mitochondria or other microorganelles were found in these dense lesions. These findings are thought not to be specific to FCMD, but seem to reflect diaphragm muscle fatigue, because, there were no such lesions in the diaphragm muscle of a 2-year-old infant not exhibiting chronic respiratory failure or in muscle at other sites in all patients.     

A genetic study of the Fukuyama type congenital muscular dystrophy

A genetic study was carried out on 153 families with 186 Fukuyama type congenital progressive muscular dystrophy (FCMD) patients. Consanguineous marriage of parents was found in 41 families (26.80%). Inbreeding coefficients in the patients was 10 times as high as that of the general population. Both sexes were almost equally affected (M:F = 1.1:1.0). No single parent of the patients was affected. Recurrence among siblings was frequent (9 out of 41 siblings in offspring of related parents and 18 out of 110 siblings in offspring of unrelated parents were affected. The segregation ratio was 23.91-27.08% in offspring of related parents, 20.00-22.94% in offspring of unrelated parents, these values being not significantly different from the 25% expected from the assumption of autosomal recessive mode of inheritance. In the sample two twin pairs were included, of which one male isosexual pair was concordant. Sporadic cases were not significantly more numerous than expected. All these data indicate that the disorder is caused by homozygosity of an autosomal recessive gene. Frequency of the gene was estimated to be 5.2-9.7 X 10(-3) and frequency of the patients 6.9-11.9 X 10(-5). Mutation rate was estimated to be 6.9-11.9 X 10(-5).