BACKGROUND: As the most common subtype of adult muscular dystrophy worldwide, large cohort reports on myotonic dystrophy type I (DM1) in China are still lacking. This study aims to analyze the genetic and clinical characteristics of Chinese Han DM1 patients.
METHODS: Based on the multicenter collaborating effort of the Pan-Yangtze River Delta Alliance for Neuromuscular Disorders, patients with suspected clinical diagnoses of DM1 were genetically confirmed from January 2020 to April 2023. Peak CTG repeats in the DMPK gene were analyzed using triplet repeat-primed PCR (TP-PCR) and flanking PCR. Time-to-event analysis of onset age in females and males was performed. Additionally, detailed clinical features and longitudinal changes from the disease onset in 64 DM1 patients were retrospectively collected and analyzed. The Epworth Sleepiness Scale and Fatigue Severity Scale were used to quantify the severity of daytime sleepiness and fatigue.
RESULTS: Among the 211 genetically confirmed DM1 patients, the mean age at diagnosis was 40.9 ± 12.2 (range: 12-74) with a male-to-female ratio of 124:87. The average size of CTG repeats was 511.3 (range: 92-1945). Among the DM1 patients with comprehensive clinical data (n = 64, mean age 41.0 ± 12.0), the age at onset was significantly earlier in males than in females (4.8 years earlier, p = 0.026). Muscle weakness (92.2%), myotonia (85.9%), and fatigue (73.4%) were the most prevalent clinical features. The predominant involved muscles at onset are hands (weakness or myotonia) (52.6%) and legs (walking disability) (42.1%). Of them, 70.3% of patients had daytime sleepiness, 14.1% had cataract surgery, 7.8% used wheelchairs, 4.7% required ventilatory support, and 1.6% required gastric tubes. Regarding the comorbidities, 4.7% of patients had tumors, 17.2% had diabetes, 23.4% had dyspnea, 28.1% had intermittent insomnia, 43.8% experienced dysphagia, and 25% exhibited cognitive impairment. Chinese patients exhibited smaller size of CTG repeats (468 ± 139) than those reported in Italy (613 ± 623), the US (629 ± 386), and Japan (625 [302, 1047]), and milder phenotypes with less multisystem involvement.
CONCLUSIONS: The Chinese Han DM1 patients presented milder phenotypes compared to their Caucasian and Japanese counterparts. A male predominance and an early age of onset were identified in male Chinese Han DM1 patients.

UNASSIGNED: Sialidosis is a rare disorder caused by mutations in the NEU1 gene located on chromosome 6p21.3, constituting a group of autosomal recessive diseases. Enzyme activity analysis, electron microscopy examination and genetic testing are reliable methods for diagnosis. Despite previous reports on the disease, its rarity means that its clinical manifestations and prognosis still warrant attention due to the limited amount of information available.
UNASSIGNED: We report a case of a 40-year-old woman who was admitted to our hospital for worsening dysarthria of 16 years duration and facial and limb twitching that had been present for 2 years. Genetic testing was undertaken.
UNASSIGNED: Genetic testing confirmed type I sialidosis, the first reported instance of this disease in the Hainan Free Trade Port in China. The patient did not have the typical cherry-red spot in the fundus. Despite aggressive treatment, she died of status epilepticus 2 months later. This result indicates that the disease has a poor prognosis.
UNASSIGNED: Cherry-red spots in the fundus are characteristic features of type I sialidosis and it has been referred to as the cherry-red spot myoclonus syndrome. We hypothesise that environmental factors may also play a significant role. Overemphasis on the presence of cherry-red spots may mislead clinicians and delay diagnosis. Furthermore, patients presenting with isolated myoclonus should undergo visual evoked potential and somatosensory evoked potential tests, as well as genetic testing to confirm or rule out sialidosis.

OBJECTIVE: Electrodiagnostic testing is an important screening test for myotonic dystrophy type 1 (DM1). Although myotonic discharges are observed on electromyography in cases of DM1, it is difficult to distinguish DM1 from other myotonic disorders clinically. In the present study, afterdischarges, another type of pathological potential revealed by electrodiagnostic testing, were analyzed, and their role in distinguishing DM1 from other myotonic disorders was explored.
METHODS: Data from 33 patients with myotonic discharges on electromyography were analyzed retrospectively. According to gene testing, the patients were divided into DM1 (n = 20) and non-DM1 myotonia (n = 13) groups. Afterdischarges were investigated by retrospectively evaluating the electrodiagnostic findings of motor nerve conduction studies, F-waves, and repetitive nerve stimulations.
RESULTS: Afterdischarges were observed in 17 of the 20 patients with DM1, with an occurrence rate of approximately 85%. However, afterdischarges were absent in all patients with non-DM1 myotonia. There were significant differences in the occurrence rate between the two groups (P < 0.01).
CONCLUSIONS: Afterdischarges may serve as a suggestive role in clinical diagnosis of DM1. The discovery that DM1 can present with afterdischarges may pave a new way to study the pathogenesis of DM1.

BACKGROUND: This study aimed to characterize the genetic, pathological, and clinical alterations of 17 patients in China presenting with nondystrophic myotonia (NDM) and to analyze the relationship between genotype and clinical phenotype.
METHODS: CLCN1 and SCN4A genes in patients with clinical features and muscle pathology indicative of NDM were sequenced. Furthermore, KCNE3 and CACNA1S genes were assessed in patients with wild-type CLCN1 and SCN4A.
RESULTS: Patients may have accompanying atypical myopathy as well as muscle hypertrophy, secondary dystonia, and joint contracture as determined by needle electromyography. All the study participants were administered mexiletine in combination with carbamazepine and showed significant improvements in myotonia symptoms in response to this therapy. CLCN1 gene mutation was detected in 8 cases diagnosed with myotonia congenital using gene screening. The detected mutations included 5 missense, 2 nonsense, 1 deletion, and 2 insertions. Further gene analysis showed 4 mutations in the SCN4A gene in patients diagnosed with paramyotonia congenita.
CONCLUSIONS: Myotonia congenita and paramyotonia congenita are the predominant forms of NDM in China. NDM may be best diagnosed using genetic analysis in associated with clinical features.

Objective:To study the characteristics of bone-conducted vibration vestibular evoked myogenic potential（BCV-VEMP） in normal adult with and without myotonia rectification, and to provide accurate reference for clinical vestibular function evaluation. Methods:Thirty normal adults（60 ears） aged 20-32 years old were selected to receive BCV-VEMP in a sitting position. BCV-VEMP were induced by B-81 bone-conducted vibrator at 129.5 FL, the P1 latency, N1 latency, P1-N1interval, amplitude, and amplitude asymmetry ratios were recorded in two test conditions. Results:Clear and repeatable waveforms of BCV-cVEMP and BCV-oVEMP were obtained in all normal adults. The P1 and N1 latencies of BCV-cVEMP were（16.00±2.02） ms and（25.04±2.57） ms, respectively, P1-N1 interval was（9.04±1.78） ms. The N1 and P1 latencies of BCV-oVEMP were（10.39±0.81） ms and（15.85±1.00） ms, respectively, iand interval was（5.46±0.86） ms. The amplitudes of BCV-cVEMP and BCV-oVEMP in two test conditions were statistically significant（P<0.05）. The amplitude asymmetry ratios of BCV-cVEMP and BCV-oVEMP after rectification were （17.03±9.14）% and （20.43±11.65）%, respectively. Conclusion:BCV-VEMP is a feasible and reliable tool for vestibular function assessment. The establishment of a normal values such as amplitude and amplitude asymmetry ratio after rectification can provide a more reliable and accurate reference.
目的：观察并分析正常成人骨导前庭诱发肌源性电位（BCV-VEMP）相关参数特征，比较肌张力修正前后双侧幅值、幅值不对称比的变化，为耳石器及其传导通路的功能评估以及眩晕疾病的诊断提供更加精准的参考依据。 方法：选取30名（60耳）20～32岁正常成年人，以坐姿进行骨导颈肌VEMP（BCV-cVEMP）和眼肌VEMP（BCV-oVEMP）测试。使用B-81骨导耳机给声，刺激强度为129.5 FL，记录修正前后的BCV-cVEMP和BCV-oVEMP的P1、N1潜伏期、P1-N1波间期、P1-N1幅值、幅值不对称比等。 结果：BCV-cVEMP和BCV-oVEMP在正常成人中的引出率均为100%。BCV-cVEMP的P1、N1潜伏期分别为（16.00±2.02） ms、（25.04±2.57） ms，波间期为（9.04±1.78） ms。BCV-oVEMP的N1、P1潜伏期分别为（10.39±0.81） ms、（15.85±1.00） ms，波间期为（5.46±0.86） ms。BCV-cVEMP和BCV-oVEMP修正前后的幅值差异均有统计学意义（P<0.05）。修正后BCV-cVEMP幅值不对称比为（17.03±9.14）%，修正后BCV-oVEMP幅值不对称比为（20.43±11.65）%。 结论：BCV-VEMP是一种可行且有效的耳石器功能检测手段。建立修正后的幅值、幅值不对称比等参数的正常范围可为前庭耳石器及其传导通路功能评估及诊断提供更准确的参考依据。.

Severe neonatal episodic laryngospasm (SNEL) is an ion channel disease characterized by recurrent life-threatening myotonia of respiratory muscle due to mutations in the voltage-gated sodium channel genes. Here we reported a newborn manifested as paroxysmal cyanosis and limb myotonia after birth. The neonate also developed muscle hypertrophy and stunted growth during the follow-up. Whole exome sequencing confirmed c.2395G>A, p.Ala799Thr heterozygous mutation of SCN4A. Carbamazepine was found to be effective on treating the disease. This case expands our understanding of the phenotype resulting from SCN4Amutations. By summarizing the characteristics of reported 16 cases in SNEL,we found they were mainly in the p.G1306E mutation. The common symptoms were upper airway muscle stiffness and feeding difficulties during neonates.When grow up, most patients have different degrees of recurrent attacks of myotonia and progressed muscle hypertrophy. Some of them have athlete-like special faces but all showed myotonic discharge in eletromyogram.
严重新生儿发作性喉痉挛(severe neonatal episodic laryngospasm，SNEL)是一种离子通道病，该病因钠电压门控通道4亚基(sodium voltage-gated channel alpha subunit 4 gene，SCN4A)基因突变导致反复发作性咽喉肌强直而危及新生儿生命。现报告1例在出生后出现阵发性发绀和四肢强直的新生儿病例，随访期间，患儿还出现四肢肌肥大和生长发育迟缓。全外显子测序证实该患儿存在SCN4A基因新型杂合突变(c.2395G>A, p.Ala799Thr)。卡马西平是治疗该病的有效药物。此病例扩展了我们对SCN4A基因突变表型的认识。总结已报道的16例SNEL病例特点，发现他们主要发生p.G1306E位点错义突变。相似症状表现为新生儿期上气道肌紧张和喂养困难，长大后多数患者表现为不同程度的发作性肌强直和进行性的肌肥大。一些患者出现“运动员”特征外貌，但几乎所有患者肌电图均有肌强直放电。.

Myotonia congenita (MC) is a rare genetic disease caused by mutations in the skeletal muscle chloride channel gene (CLCN1), encoding the voltage-gated chloride channel ClC-1 in skeletal muscle. Our study reported the clinical and molecular characteristics of six patients with MC and systematically review the literature on Chinese people. We retrospectively analyzed demographics, clinical features, family history, creatine kinase (CK), electromyography (EMG), treatment, and genotype data of our patients and reviewed the clinical data and CLCN1 mutations in literature. The median ages at examination and onset were 26.5 years (range 11-50 years) and 6.5 years (range 1.5-11 years), respectively, in our patients, and 21 years (range 3.5-65 years, n = 45) and 9 years (range 0.5-26 years, n = 50), respectively, in literature. Similar to previous reports, myotonia involved limb, lids, masticatory, and trunk muscles to varying degrees. Warm-up phenomenon (5/6), percussion myotonia (3/5), and grip myotonia (6/6) were common. Menstruation triggered myotonia in females, not observed in Chinese patients before. The proportion of abnormal CK levels (4/5) was higher than data from literature. Electromyography performed in six patients revealed myotonic changes (100%). Five novel CLCN1 mutations, including a splicing mutation (c.853 + 4A>G), a deletion mutation (c.2010_2014del), and three missense mutations (c.2527C>T, c.1727C>T, c.2017 G > C), were identified. The c.892 G > A (p.A298T) mutation was the most frequent mutation in the Chinese population. Our study expanded the clinical and genetic spectrum of patients with MC in the China. The MC phenotype in Chinese people is not different from that found in the West, while the genotype is different.

BACKGROUND: Charcot-Marie-Tooth disease (CMT) is a genetically heterogeneous hereditary neuropathy, and CMT1A is the most common form; it is caused by a duplication of the peripheral myelin protein 22 (PMP22) gene. Mutations in the transient sodium channel Nav1.4 alpha subunit (SCN4A) gene underlie a diverse group of dominantly inherited nondystrophic myotonias that run the spectrum from subclinical myopathy to severe muscle stiffness, disabling weakness, or frank episodes of paralysis.
METHODS: We describe a Chinese family affected by both CMT1A and myotonia with concomitant alterations in both the PMP22 and SCN4A genes. In this family, the affected proband inherited the disease from his father in an autosomal dominant manner. Genetic analysis confirmed duplication of the PMP22 gene and a missense c.3917G > C (p. Gly1306Ala) mutation in SCN4A in both the proband and his father. The clinical phenotype in the proband showed the combined involvement of skeletal muscle and peripheral nerves. Electromyography showed myopathic changes, including myotonic discharges. MRI revealed the concurrence of neurogenic and myogenic changes in the lower leg muscles. Sural nerve biopsies revealed a chronic demyelinating and remyelinating process with onion bulb formations in the proband. The proband\'s father presented with confirmed subclinical myopathy, very mild distal atrophy and proximal hypertrophy of the lower leg muscles, pes cavus, and areflexia.
CONCLUSIONS: This study reports the coexistence of PMP22 duplication and SCN4A mutation. The presenting features in this family suggested that both neuropathy and myopathy were inherited in an autosomal dominant manner. The proband had a typical phenotype of sodium channel myotonia (SCM) and CMT1A. However, his father with the same mutations presented a much milder clinical phenotype. Our study might expand the genetic and phenotypic spectra of neuromuscular disorders with concomitant mutations.

OBJECTIVE: Previous studies have suggested that Helicobacter pylori (H. pylori) infections may be the cause of or worsen Parkinson\'s disease symptoms. In this meta-analysis, all relevant studies were reviewed to assess whether H. pylori treatment would benefit patients with Parkinson\'s disease.
METHODS: Systemically searches were carried out in MEDLINE and other popular databases. The software RevMan 5.2 was used for meta-analysis. The mean difference (MD) was used as the effect size to draw forest plots.
RESULTS: A total of 10 qualified studies were included. For bradykinesia, the pooled MD value of stride length was -75.76, 95% CI [-109.37, -42.15, P < 0.05]; for myotonia, the pooled MD value of torque to flex was 75.24, 95% CI [27.36, 123.13, P < 0.05]. The pooled MD value of Unified Parkinson\'s Disease Rating Scale (UPDRS)-III scores before and after treatment was 6.27, 95% CI [1.30, 11.24, P < 0.05], suggesting that UPDRS-III scores improved in response to H. pylori treatment. The pooled MD value of levodopa onset time (min) was 14.91, 95% CI [8.92, 20.90, P < 0.05].
CONCLUSIONS: H. pylori treatment may improve the stride length in the bradykinesia index and significantly improve UPDRS-III scores.

暂无摘要。