Objective To evaluate Western blot analysis in diagnosing limb-girdle muscular dystrophy type 2A (LGMD2A). Methods The clinical records including their pathological and biochemical results of 4 patients with LGMD type 2 were reviewed. Histochemical and immunohistochemical staining were performed on muscle biopsy specimens from the four patients. The expressions of dysferlin and calpain-3 in muscles were analyzed by Western biol. Results All 4 LGMD patients shared some common clinical features, such as dorsal muscular atrophy of lower limbs and remarkably elevated CK. The immunohistochemical results showed partial or complete deficiency of dysferlin staining in all 4 LGMD patients. However, Western blot revealed that the calpain-3 protein in the muscle of patient 1 was completely absent, who was later diagnosed with LGMD2A. The other 3 patients had complete dysferlin deficiency with reduced calpain-3 expression and they were confirmed to be LGMD2B. Conclusions Western blot analysis of calpain-3 and dysfcrlin can be used to differentiate LGMD2A which shows absence of calpain-3 from other LGMD types which show dysferlin deficiency. Western blot is an invaluable method in clinical diagnosis of LGMD2A.

Objective To investigate muscle MRI characteristics of lower limbs in Chinese patients with dysferlinopathy. Methods Detailed clinical information of 42 patients with dysferlinopathy confirmed by Western blot or DYSF genetic test were studied retrospectively, including age, course, serum creatinine kinase (CK) and modified Gardner?Medwin and Walto score, and T1WI, STIR image. Each muscle was scored according to its fatty degeneration evaluated on T1WI (fat replacement score). The patients were divided into 3 groups:Miyoshi myopathy (MM), limb girdle muscle dystrophy 2B (LGMD 2B) and preclinical stage (asymptomatic hyperCKemia or exercise intolerance). The data including the scores of each muscle between MM and LGMD 2B were compared by ANOVA analysis and Chi square test. The relationship of fatty replacement score with course and GM?W score was analyzed by Spearman rank correlation analysis. Results Thirty nine patients underwent thigh MR scanning and 36 patients underwent leg MR scanning. At the thigh level, there is no specificity that the fatty replacement was found in both the anterior and posterior parts while the rectus femoris, sartorius and gracilis were rarely involved. At the leg level, the most severely involved muscle was the soleus, followed by gastrocnemius. It formed a sandwich?like pattern that the anterior part (anterior and posterior tibial muscle and peroneus longus muscle) and the posterior part (medial and lateral gastrocnemius) were less involved than the middle part (soleus). Of 42 patients, 14 cases were MM, and 24 were LGMD 2B. The fat replacement score of each muscle between two groups showed no significant differences (F=0.066 to 3.907,P all>0.05) except for the adductor muscle (F=5.239, P=0.028), semimembranosus (F=6.703, P=0.014) and semitendinosus (F=7.689, P=0.009). Of 4 pre?symptomatic cases, 3 showed edema of posterior part of leg on STIR, especially soleus. In all patients, the fat replacement score correlated positively with course (rs=0.732, P=0.000) and GM-W score (rs=0.485, P=0.001). Conclusions The MRI of Chinese patient with dysferlinopathy was characterized by the milder involvement of rectus femoris, sartorius and gracilis muscle in the thigh and a sandwich?like pattern in the leg, which is helpful for differential diagnosis of inflammatory Myopathy versus other types of muscular dystrophy.

Objective To investigate the clinical features and electron transfer flavoprotein dehydrogenase (ETFDH) gene mutations in 35 Chinese patients with lipid storage myopathy. Methods The clinical data of 35 cases with lipid storage myopathy confirmed by muscle biopsy were collected. The sequences of all 13 exons of ETFDH were analyzed. Results All 35 patients showed proximal weakness. Ten of them demonstrated masseter weakness and 28 of them showed weakness in neck flexion. Twenty-nine of 32 patients who were followed up showed improvement after treatment with VitB2 and CoQ10. Mutations of ETFDH were found in 30 of 35 patients,which included 8 homozygosises,20 compound heterozygosises and 2 single heterozygosises. Fourteen novel mutations were found, including 9 missense mutations ( c. 3G > C, c. 152G>A, c. 191G > A, c.349G>C, c.433G>C, c. 949C > A, c. 1454C > G, c. 1744A >T and c. 1763A>G), 1 nonsense mutation(c. 172G>T), 2 deletions(c. 1282_1283del and 1773_1774del) and 2 splice mutations (c. 405 + 1G > T and c. 1691 -3C > G). Nine of them showed c. 250G > A mutation and 6 of them showed c. 770A > G mutation. Conclusions Lipid storage myopathy is presented as proximal weakness. Multiple acyl-CoA dehydrogenase deficiency caused by mutations of ETFDH is the major cause of lipid storage disease in this group. ETFDH c. 250G > A and c. 770A > G mutations show a high frequency.

Limb girdle muscular dystrophy (LGMD) is characterized by progressive proximal muscle weakness with high genetic heterogeneity.LGMD is the fourth prevalent form of muscular dystrophies in the adult neurology department.Since most patients are juvenile-or adult-onset and present as limb muscle weakness,it would be easily misdiagnosed as myositis or metabolic myopathies.The final diagnosis depends on muscle immunohistochemical staining,Western blotting and genetic screening.In China,LGMD2B and LGMD2A are the most prevalent forms,accounting for 74.3％ in overall LGMD.Patients with LGMD2B usually have onset age between 19-27 years old.LGMD2B patients present as asymptomatic hyper creatine kinase emia (CK) at the early stage,and later develop to typical proximal muscle weakness with bilateral calf atrophy and extremely high serum CK.The onset age of LGMD2A patients is between 7-18 years old.LGMD2A patients presented as proximal muscle weakness with or without bilateral scapular winging and Achilles tendon contractures.Serum CK can be moderately or highly elevated.Current therapies are mainly supportive and the effective treatment is insufficient.The ongoing global elinical history study and gene therapy bring us new hope for treating LGMD in the coming future.

The clinical manifestation of myasthenia gravis is due to the acetylcholine transmission defect of neuromuscular junction caused by autoimmune disturbance. With the intensive understanding of the pathogenesis and the emerging of specific immunological targeting therapy, therapeutic investigations are widely expanding. A multi-target therapy pattern is now available based on treatments primed to distinct immunopathological processes and improving neuromuscular junction transmission. We will comment the status and problems in this article.

The clinical symptoms of myasthenia gravis (MG) in women are closely related to pregnancy, and the outcome of pregnancy and neonates is related to MG disease control, comorbidities and antibody types. The exacerbation of muscle weakness usually appeared in the first trimester and postpartum 0-3 months. The adverse pregnancy outcomes of MG mothers are mainly fetal arrest and abortion. Neonatal muscle weakness and congenital joint flexion are common neuromuscular lesions in childbirth. During pregnancy, the immune system of MG pregnant women is regulated by estrogen/progesterone/prolactin/glucocorticoid, and the main result is to inhibit pro-inflammatory response and promote immune tolerance. However, the specific interaction between MG and pregnancy remains to be elucidated in prospective cohort studies.

Objective To summarize the characteristic of muscle MRI of lower limbs in patients with GNE myopathy and to explore the correlation between the fatty degenerative score of muscle MRI and clinical phenotype.Methods This was a prospective study. Seventeen patients with genetically confirmed GNE myopathy,having lower limb muscle MRI test and completed clinical and laboratory data.The degree of fatty degeneration in 18 muscles of lower limbs in each patient was grading.According to the GM-W score, these patients were divided into two groups.GM-W score≤3 were divided into mild group(n=8)and GM-W score≥ 4 were divided into severe group(n=9). Kruskal-Wallis test was used to compare the fatty degenerative score in different muscles of the thigh and the calf level;Mann-Whitney U test was used to compare score of the same muscle between mild and severe group;Spearman rank correlation test was used to analysis the relationship between fatty degenerative score and the course of disease (year), GM-W score, creatinine kinase (IU/L), respectively.Results At the thigh level, the most severely involved muscle of GNE myopathy was semi-tendinosusand adductor, followed by semi-membranous, biceps femoris and gracilis. There was no statistically significant difference in the fatty degenerative score of the above-mentioned muscles (P=0.058). At the calf level, the most severely involved muscle was medial of soleus which score was 4.0(3.0, 4.0), followed by tibialis anterior,extensor digitorum longus and lateral of soleus. There was no significant difference of the above (P=0.259).The fatty degenerative score showed difference between the mild and severe group at sartorius and adductor(P<0.05).At the calf level,the fatty degenerative score in peroneus longus, medial of soleus, lateral of soleus, medial of gastrocnemius and lateral of gastrocnemius showed difference between groups(P<0.05).The total score of fatty degenerative of Lower limb muscles was positively correlated with GM-W score(r=0.730, P<0.05). There were positive correlations between the score of fatty degenerative of the sartorius,peroneal longus,lateral of soleus,medial of gastrocnemius, lateral of gastrocnemius and the GM-W scores( r=0.630,0.845,0.569,0.591,0.640, 0.659,P<0.05).The total score of fatty degenerative of Lower limb muscles was not correlated with the level of creatine kinase(P=0.582), course of disease(P=0.601) and age of onset(P=0.850). Conclusions GNE myopathy in the thigh level within the adductor muscle and posterior muscle involvement, calf level to the tibial anterior muscle early involvement. The total score of fatty degenerative of lower limb muscles is positively correlated with GM-W score,but not correlated with the level of creatine kinase,course of disease and age of onset.

Objective:To investigate the clinical features, imaging features and gene mutation of a paitent with alanyl-transfer ribonucleic acid synthetase 2 (AARS2) gene mutation- related leukodystrophy and further improve the understanding of this rare disease.Methods:Clinical data of a patient with leukodystrophy associated with AARS2 gene mutation diagnosed in October 2020 at Xiamen Hospital of Beijing University of Chinese Medicine and Huashan Hospital of Fudan University were collected.Results:The male patient, 25 years old, was admitted with the clinical manifestations, including chronic onset dyskinesia, ataxia, nystagmus and psoriasis. Head magnetic resonance imaging (MRI) showed bilateral white matter lesions and cerebellar atrophy. Spine MRI showed vertebral body incomplete fusion. Gene detection showed heterozygous compound AARS2 gene mutation [c.985C>T chr6:44275041(p.R329C) and c.452T>C chr6:44279256(p.M151T)].Conclusions:AARS2 gene mutation-related leukodystrophy is a rare mitochondrial disease in clinical practice. The patient presented with progressive motor deficits in the lower limbs, ataxia, relatively retained cognitive function. MRI revealed abnormal symmetry of corpus callosum and bilateral paraventricular white matter. Heterozygous compound AARS2 gene mutations [c.985C>T chr6:44275041 (p.R329C) and c.452T>C chr6:44279256 (p.M151T)] are one of the pathogenic factors leading to hereditary leukodystrophy.

Objective To summarize the clinical features,natural history and causes of death of mitochondrial encephalomyopathy,lactic acidosis and stroke-like episodes (MELAS).Methods We retrospectively evaluated the clinical findings of 64 patients diagnosed as MELAS more than 3 years (death cases excluded) in Huashan Hospital from January 2005 to March 2017 and analyzed the natural course and the causes of death of the disease.Results Among 64 patients,the male-to-female ratio was 1.3 ∶ 1.Median onset age was 20.5 (16.8) years.The peak of incidence age was from 14 to 22 years.The most common features of MELAS in acute phase were seizures (48/64,75.0％),headache (41/64,64.1％),blurred vision (37/64,57.8％),nausea and vomiting (27/64,42.1％),fever (25/64,39.1％),mental and behavioral disorder (24/64,37.5％).Lactate dehydrogenase (31/60,51.6％),resting blood lactic acid (43/58,74.1％) and cerebral spinal fluid lactic acid (9/9) were elevated.Abnormal findings in electroencephalogram (36/40,90.0％),electrocardiogram (37/47,78.7％),electromyography (25/41,61.0％) were detected.In this cohort,20 patients (20/64,31.3％) with MELAS were dead.A Kaplan-Meier survival curve showed the estimated overall median survival time was 12 years.The median survival time of the group onset before sex maturity (≤ 14 years) was 8 years and that in the group onset after sex maturity (＞ 14 years) was 21 years.The causes of death were cardiogenic incidence (4/20,20.0％),pulmonary infection (4/20,20.0％),lactic acidosis (2/20,10.0％) and status epilepticus (2/20,10.0％).Conclusions MELAS is usually presented in young people associated with high mortality rate.The leading causes of death are cardiogenic,pulmonary infection and lactic acidosis.

Myotonic dystrophy type 1 (DM1) is a multisystem trinucleotide repeat expansion disorder usually referred to the department of neurology with complaints of progressive muscle weakness and myotonia. This article reported a 33-year-old female patient with DM1 presenting with acute respiratory failure.Muscle biopsy in vastus lateralis showed significantly increased internal nuclei. Genetic test show CTG repeat expansions with the size of (847±76) in dystrophia myotonica protein kinase (DMPK) gene on chromosome 19. This case report broadens the clinician′s understanding of the atypical clinical manifestations of DM1, so as to avoid missed diagnosis and misdiagnosis.