肢带型肌营养不良2B型的临床和病理特点

目的研究肢带型肌营养不良2B型的临床及病理特点。方法回顾性分析5例肢带型肌营养不良2B型患者的临床资料和骨骼肌病理检查结果。结果5例(3例四肢,2例双下肢)表现肌肉萎缩、肌无力,缓慢起病,进行性加重。病理检查5例骨骼肌均有不同程度肌纤维变性、坏死、再生,不同程度炎性细胞浸润;免疫组化染色:5例患者抗dysferlin单克隆抗体均无表达,抗Dystrophy、Sarcoglycan、dystroglycan单克隆抗体均表达正常,抗CD8+T细胞单克隆抗体均无表达,抗组织相容性复合体(MHC)-1单克隆抗体表达均上调。结论肢带型肌营养不良2B型的临床特点是缓慢起病,进行性加重的四肢(或双下肢)肌萎缩、肌无力;其病理学特点与多发性肌炎的改变相似。     

肢带型肌营养不良2A型临床和病理特点

目的探讨肢带型肌营养不良2A型(LGMD2A)的临床及病理特点。方法回顾性分析7例基因确诊的LGMD2A型患者的临床资料和骨骼肌病理检查结果。结果 1例尚未出现临床症状。1例症状很轻,仅有易疲劳伴运动时小腿痛,肌力检查正常。另外5例均以下肢近端肌无力缓慢起病,进行性加重,之后上肢近端肌不同程度受累,均伴有翼状肩胛及跟腱挛缩,仅1例见腓肠肌肥大及脊柱畸形,下肢近端肌群肌力检查提示伸髋及髋内收受累最重,其次为屈髋及屈膝,髋外展及伸膝受累最轻。该5例患者的骨骼肌病理均呈肌营养不良样病理改变,表现为肌纤维大小不等、结缔组织增生及不同程度坏死、再生,NADH染色2例见大量分叶纤维。结论 LGMD2A的临床变异较大,其典型临床特点为慢性进行性近端肌无力伴翼状肩胛、关节挛缩,股后肌群及内侧肌群较股前肌群受累明显。其肌肉病理缺乏特异性。     

Cardiac involvement in limb-girdle muscular dystrophy 2I

Background The C826A mutation in the fukutin-related protein (FKRP) gene is typically associated with autosomal recessive limb-girdle muscular dystrophy 2I (LGMD2I) but oligosymptomatic phenotypes and patients with predominant cardiac involvement are also described. Objective To assess cardiac involvement in patients with LGMD2I. Patients Nine patients from 5 families (2 female, 7 male) homozygous for the 826C > A FKRP mutation were included. Methods Additional to conventional cardiac investigations (electrocardiography and echocardiography) the patients underwent cardiovascular magnetic resonance imaging (CMR). Results/Conclusion Cardiac involvement was detected by CMR in eight of nine patients (reduced left ventricular ejection fraction in 6, enlargement of left ventricular end-diastolic volume in 2 and left ventricular mass in 2) and in four patients by conventional cardiac diagnostic investigations. Two of the nine patients showed no muscle weakness or atrophy but suffered myalgias; both had cardiac manifestation of the disease. CMR is a sensitive method for detecting cardiac abnormalities in patients with LGMD2I and can be used for early detection of mild or subclinical cardiac involvement. Received in revised form: 23 February 2006     

FKRP mutations cause congenital muscular dystrophy 1C and limb-girdle muscular dystrophy 2I in Asian patients

Mutation in the fukutin-related protein (FKRP) gene causes alpha-dystroglycanopathies, a group of autosomal recessive disorders associated with defective glycosylated alpha-dystroglycan (α-DG). The disease phenotype shows a broad spectrum, from the most severe congenital form involving brain and eye anomalies to milder limb-girdle form. FKRP-related alpha-dystroglycanopathies are common in European countries. However, a limited number of patients have been reported in Asian countries. Here, we presented the clinical, pathological, and genetic findings of nine patients with FKRP mutations identified at a single muscle repository center in Japan. Three and six patients were diagnosed with congenital muscular dystrophy type 1C and limb-girdle muscular dystrophy 2I, respectively. None of our Asian patients showed the most severe form of alpha-dystroglycanopathy. While all patients showed a reduction in glycosylated α-DG levels, to variable degrees, these levels did not correlate to clinical severity. Fifteen distinct pathogenic mutations were identified in our cohort, including five novel mutations. Unlike in the populations belonging to European countries, no common mutation was found in our cohort.     

Progressive dysphagia in limb-girdle muscular dystrophy type 2B

Dysphagia has not been reported in genetically confirmed limb-girdle muscular dystrophy type 2B (LGMD2B). A 40-year-old woman reported exercise-induced calf pain at age 34, followed by progressive lower and upper limb weakness. At age 38, progressive dysphagia for solids, and subsequently liquids, ensued. Endoscopic and videofluoroscopic-radiological findings indicated a myopathic swallowing disorder. Molecular genetic analysis confirmed two dysferlin gene mutations consistent with a compound heterozygote state. Progressive dysphagia should be considered as part of the expanding dysferlinopathy phenotype.     

Cardiac and respiratory failure in limb-girdle muscular dystrophy 2I

Mutations in the gene encoding fukutin-related protein cause limb-girdle muscular dystrophy 2I. In this multicenter retrospective analysis of 38 patients, 55.3% had cardiac abnormalities, of which 24% had developed cardiac failure. Heterozygotes for the common C826A mutation developed cardiac involvement earlier than homozygotes. All patients initially improved while receiving standard therapy. Independent of cardiac status, forced vital capacity was below 75% in 44.4% of the patients. There was no absolute correlation between skeletal muscle weakness and cardiomyopathy or respiratory insufficiency. These complications are a primary part of this specific type of limb-girdle muscular dystrophy, with important implications for management.     

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.     

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.     

Two siblings with limb-girdle muscular dystrophy type 2E responsive to deflazacort

Two siblings were evaluated for progressive proximal weakness and elevated creatine kinase. Immunohistochemical staining in the brother’s muscle biopsy showed near absence of all four sarcoglycan subunits. Clinical progression prompted a trial of deflazacort in both siblings. At 22 months of drug therapy, both patients have stable or improved strength testing. Further analysis on the muscle biopsy revealed homozygous β-sarcoglycan gene mutation (S114F), consistent with the limb-girdle muscular dystrophy type 2E (LGME 2E). Despite the severe phenotype, deflazacort has a beneficial effect on slowing disease progression in LGME 2E similar to that seen in Duchenne muscular dystrophy.     

Cognitive profile and MRI findings in limb-girdle muscular dystrophy 2I

Limb-girdle muscular dystrophy 2I (LGMD2I) is a neuromuscular disorder with a heterogeneous phenotype. It is caused by mutations in the Fukutin Related Protein (FKRP) gene, which is ubiquitously expressed in human tissues. FKRP functions in CNS are largely unknown. To investigate possible cognitive impairment in LGMD2I and to describe brain MRI features. Ten LGMD2I patients (four males and six females, mean age 44 years, age range 19–69 years) were assessed with an extensive neuropsychological battery, psychopathological tests and neuromuscular specific quality-of-life questionnaire. Adults were compared with ten matched healthy controls. All patients underwent complete neurological examination, and nine underwent brain MRI scanning. Patients showed a fairly specific cognitive profile with mild impairment in executive functions and visuo-spatial planning without substantial impairment in global and logic IQ. MRI findings were heterogeneous: four patients showed non-specific white matter abnormalities; two patients showed moderate ventriculomegaly; three patients showed mild enlargement of subarachnoid spaces, without a specific pattern. Cerebellar atrophy was marked in one patient. Abnormal glycosylation of α-dystroglycan in LGMD2I may interfere with brain development and cognitive performances involving the frontal and posterior parietal regions, but does not result in specific brain MRI abnormalities.     

微量标本Western blot在诊断肢带型肌营养不良2A型中的应用

目的 探讨微量标本Western blot在诊断肢带型肌营养不良2A型中的应用.方法 对73例以肢体近端肌肉受累为首要临床表现的进行性肌营养不良患者行开放式骨骼肌活体组织检查,标本行组织化学染色以及抗dystrophin-N、C、R,α、β、γ、δ-sarcoglycan,dysferlin,caveolin-3单克隆抗体免疫组织化学染色.对其中已经除外dystrophin、sarcoglycans、dysferlin、caveolin-3蛋白异常的29例患者再行骨骼肌Western blot抗calpain-3、caveolin-3单克隆抗体免疫反应.结果 共有10例患者被确诊为肢带型肌营养不良2A型,其临床特点均为肢体近端肌无力起病,血清肌酸激酶不同程度升高,肌电图呈肌源性改变.组织化学染色见肌纤维大小不一,可见不同程度肌纤维变性、坏死和再生,结缔组织增生,6例见分叶状肌纤维;免疫组织化学染色见肌纤维中dystrophin、sarcoglycan、dysferlin、caveolin-3蛋白均正常表达.Western blot发现该10例患者相对分子质量94 000条带(calpain-3)与Duchenne/Becker型肌营养不良对照相比,呈完全(8例)或部分(2例)缺失;30 000区域附加条带均呈弱表达,22 000区域条带(caveolin-3)均正常表达.结论 骨骼肌微量标本Western blot是诊断LGMD2A的有效方法,适用于临床LGMD的分型诊断.     

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.     

A novel mutation in two families with limb-girdle muscular dystrophy type 2C

The authors present three unrelated North American patients with limb-girdle muscular dystrophy type 2C. Muscle biopsies suggested gamma-sarcoglycan deficiencies for all three patients. Patients 1 and 2 had a novel homozygous E263K missense mutation on exon 8 of gamma-sarcoglycan (SGCG). Patient 3 had del521T on her maternal allele and an exon 6 deletion on her paternal allele. Patients 1 and 2 are of Puerto Rican ancestry, suggesting the presence of a founder mutation in that population.     

Intrafamilial phenotypic variation in limb-girdle muscular dystrophy type 2C with compound heterozygous mutations

Two Japanese-Brazilian siblings with type 2C limb girdle muscular dystrophy showed a maternal 521-T deletion in exon 6 and a larger paternal deletion of exon 6 in the gamma-sarcoglycan gene. One sib was ambulant at 29 years of age, whereas the other sib was confined to a wheelchair at the age of 12. Sarcoglycan staining of the muscle was reduced in both siblings but it did not correlate with the observed variability of the clinical severity.     

Identical dysferlin mutation in limb-girdle muscular dystrophy type 2B and distal myopathy

Limb-girdle muscular dystrophy type 2B (LGMD2B) and Miyoshi myopathy (MM) are autosomal recessive disorders caused by mutations in the dysferlin gene on chromosome 2p13. The authors studied a large Russian family with both LGMD2B and MM. All affected individuals, as well as one preclinical boy with dystrophic changes on muscle biopsy, were found to be homozygous for a novel dysferlin mutation, TG573/574AT (Val67Asp). This finding supports the view that additional factors (e.g., modifier genes) contribute to the phenotypic expression of causative mutations in dysferlinopathies.