Heterozygous Seryl-tRNA Synthetase 1 Variants Cause Charcot-Marie-Tooth Disease.

OBJECTIVE: Despite the increasing number of genes associated with Charcot-Marie-Tooth (CMT) disease, many patients currently still lack appropriate genetic diagnosis for this disease. Autosomal dominant mutations in aminoacyl-tRNA synthetases (ARSs) have been implicated in CMT. Here, we describe causal missense mutations in the gene encoding seryl-tRNA synthetase 1 (SerRS) for 3 families affected with CMT. METHODS: Whole-exome sequencing was performed in 16 patients and 14 unaffected members of 3 unrelated families. The functional impact of the genetic variants identified was investigated using bioinformatic prediction tools and confirmed using cellular and biochemical assays. RESULTS: Combined linkage analysis for the 3 families revealed significant linkage (Zmax LOD = 6.9) between the genomic co-ordinates on chromosome 1: 108681600-110300504. Within the linkage region, heterozygous SerRS missense variants segregated with the clinical phenotype in the 3 families. The mutant SerRS proteins exhibited reduced aminoacylation activity and abnormal SerRS dimerization, which suggests the impairment of total protein synthesis and induction of eIF2α phosphorylation. INTERPRETATION: Our findings suggest the heterozygous SerRS variants identified represent a novel cause for autosomal dominant CMT. Mutant SerRS proteins are known to impact various molecular and cellular functions. Our findings provide significant advances on the current understanding of the molecular mechanisms associated with ARS-related CMT. ANN NEUROL 2023;93:244-256.

Transfer of miR-877-3p via extracellular vesicles derived from dental pulp stem cells attenuates neuronal apoptosis and facilitates early neurological functional recovery after cerebral ischemia-reperfusion injury through the Bclaf1/p53 signaling pathway.

Cerebral ischemia-reperfusion injury (I/RI) is one of the principal pathogenic factors in the poor prognosis of ischemic stroke, for which current therapeutic options to enhance neurological recovery are notably insufficient. Dental pulp stem cell-derived extracellular vesicles (DPSC-EVs) have promising prospects in stroke treatment and the specific underlying mechanisms have yet to be fully elucidated. The present study observed that DPSC-EVs ameliorated the degree of cerebral edema and infarct volume by reducing the apoptosis of neurons. Furthermore, the miRNA sequencing and functional enrichment analysis identified that miR-877-3p as a key component in DPSC-EVs, contributing to neuroprotection and anti-apoptotic effects. Following target prediction and dual-luciferase assay indicated that miR-877-3p interacted with Bcl-2-associated transcription factor (Bclaf1) to play a function. The miR-877-3p inhibitor or Bclaf1 overexpression reversed the neuroprotective effects of DPSC-EVs. The findings reveal a novel therapeutic pathway where miR-877-3p, transferred via DPSC-EVs, confers neuroprotection against cerebral I/RI, highlighting its potential in promoting neuronal survival and recovery post-ischemia.

Genotype-phenotype correlations of AR-CMT2S in a cohort of axonal Charcot-Marie-Tooth patients from Central South China.

BACKGROUND AND AIMS: This study aimed to report nine Charcot-Marie-Tooth disease (CMT) families with six novel IGHMBP2 mutations in our CMT2 cohort and to summarize the genetic and clinical features of all AR-CMT2S patients reported worldwide. METHODS: General information, clinical and neurophysiological data of 275 axonal CMT families were collected. Genetic screening was performed by inherited peripheral neuropathy related genes panel or whole exome sequencing. The published papers reporting AR-CMT2S from 2014 to 2023 were searched in Pubmed and Wanfang databases. RESULTS: In our CMT2 cohort, we detected 17 AR-CMT2S families carrying IGHMBP2 mutations and eight were published previously. Among these, c.743 T > A (p.Val248Glu), c.884A > G (p.Asp295Gly), c.1256C > A (p.Ser419*), c.2598_2599delGA (p.Lys868Sfs*16), c.1694_1696delATG (p.Asp565del) and c.2509A > T (p.Arg837*) were firstly reported. These patients prominently presented with early-onset typical axonal neuropathy and without respiratory dysfunction. So far, 56 AR-CMT2S patients and 57 different mutations coming from 43 families have been reported in the world. Twenty-nine of 32 missense mutations were clustered in helicase domain and ATPase region. The age at onset ranged from 0.11to 20 years (Mean ± SD: 3.43 ± 3.88 years) and the majority was infantile-onset (<2 years). The initial symptoms included weakness of limbs (19, 29.7%), delayed milestones (12, 18.8%), gait disturbance (11, 17.2%), feet deformity (8, 12.5%), feet drop (8, 12.5%), etc. INTERPRETATION: AR-CMT2S accounted for 6.2% in our CMT2 cohort. We firstly reported six novel IGHMBP2 mutations which expanded the genotypic spectrum of AR-CMT2S. Furthermore, 17 AR-CMT2S families could provide more resources for natural history study, drug research and development.

Genetic and clinical profile of 15 Chinese families with GDAP1-related Charcot-Marie-Tooth disease and identification of H256R as a frequent mutation.

BACKGROUND AND AIMS: Mutations in ganglioside-induced differentiation-associated protein 1 (GDAP1) cause axonal or demyelinating Charcot-Marie-Tooth disease (CMT) with autosomal dominant or recessive inheritance. In this study, we aim to report the genotypic and phenotypic features of GDAP1-related CMT in a Chinese cohort. METHODS: Clinical, neurophysiological, genetic data, and available muscle/brain imaging information of 28 CMT patients with GDAP1 variants were retrospectively collected. RESULTS: We identified 16 GDAP1 pathogenic variants, among which two novel variants c.980dup(p.L328FfsX25) and c.480+4T>G were first reported. Most patients (16/28) presented with AR or AD CMT2K phenotype. Clinical characteristics in our cohort demonstrated that the AR patients presented earlier onset, more severe phenotype compared with the AD patients. Considerable intra-familial phenotypic variability was observed among three AD families. Muscle atrophy and fatty infiltration in the lower extremity were detected by Muscle magnetic resonance imaging (MRI) scans in four patients. MRI showed two AR patients showed more severe muscle involvement of the posterior compartment than those of the anterolateral compartment in the calf. One patient carrying Q38*/H256R variants accompanied with mild periventricular leukoaraiosis. CONCLUSIONS: In this study, we conducted an analysis of clinical features of the GDAP1-related CMT patients, expanded the mutation spectrum in GDAP1 by reporting two novel variants, and presented the prevalent occurrence of the H256R mutation in China. The screening of GDAP1 should be particularly emphasized in Chinese patients with CMT2, given the incomplete penetrance and pathogenic inheritance patterns involving dominant and recessive modes.

Expanding the genetic and clinical spectrum of SORD-related peripheral neuropathy by reporting a novel variant c.210T>G and evidence of subclinical muscle involvement.

BACKGROUND AND AIMS: Biallelic variants in the sorbitol dehydrogenase (SORD) gene have been identified as the genetic cause of autosomal recessive (AR) peripheral neuropathy (PN) manifesting as Charcot-Marie-Tooth disease type 2 (CMT2) or distal hereditary motor neuropathy (dHMN). We aim to observe the genetic and clinical spectrum of a cohort of patients with SORD-related PN (SORD-PN). METHODS: A total of 107 patients with AR or sporadic CMT2/dHMN underwent molecular diagnosis by whole-exome sequencing and subsequent Sanger sequencing validation. Available phenotypic data for SORD-PN were collected and analyzed. RESULTS: Eleven (10.28%) of 107 patients were identified as SORD-PN, including four with CMT2 and seven with dHMN. The SORD variant c.210 T > G;p.His70Gln in F-d3 was firstly reported and subsequent analysis showed that it resulted in loss of SORD enzyme function. Evidence of subclinical muscle involvement was frequently detected in patients with SORD-PN, including mildly to moderately elevated serum creatine kinase (CK) levels in 10 patients, myogenic electrophysiological changes in one patient, and muscle edema in five patients undergoing lower extremity MRI. Fasting serum sorbitol level was 88-fold higher in SORD-PN patients (9.69 ± 1.07 mg/L) than in healthy heterozygous subjects (0.11 ± 0.01 mg/L) and 138-fold higher than in healthy controls (0.07 ± 0.02 mg/L). INTERPRETATION: The novel SORD variant c.210 T > G;p.His70Gln and evidence of subclinical muscle involvement were identified, which expanded the genetic and clinical spectrum of SORD-PN. Subclinical muscle involvement might be a common but easily overlooked clinical feature. The serum CK and fasting serum sorbitol levels were expected to be sensitive biomarkers confirmed by follow-up cohort study.

Diagnostic value of nerve conduction study in NOTCH2NLC-related neuronal intranuclear inclusion disease.

BACKGROUND AND AIMS: Neuronal intranuclear inclusion disease (NIID) is a rare progressive neurodegenerative disorder mainly caused by abnormally expanded GGC repeats within the NOTCH2NLC gene. Most patients with NIID show polyneuropathy. Here, we aim to investigate diagnostic electrophysiological markers of NIID. METHODS: In this retrospective dual-center study, we reviewed 96 patients with NOTCH2NLC-related NIID, 94 patients with genetically confirmed Charcot-Marie-Tooth (CMT) disease, and 62 control participants without history of peripheral neuropathy, who underwent nerve conduction studies between 2018 and 2022. RESULTS: Peripheral nerve symptoms were presented by 53.1% of patients with NIID, whereas 97.9% of them showed peripheral neuropathy according to electrophysiological examinations. Patients with NIID were characterized by slight demyelinating sensorimotor polyneuropathy; some patients also showed mild axonal lesions. Motor nerve conduction velocity (MCV) of the median nerve usually exceeded 35 m/s, and were found to be negatively correlated with the GGC repeat sizes. Regarding the electrophysiological differences between muscle weakness type (n = 27) and non-muscle weakness type (n = 69) of NIID, nerve conduction abnormalities were more severe in the muscle weakness type involving both demyelination and axonal impairment. Notably, specific DWI subcortical lace sign was presented in only 33.3% of muscle weakness type, thus it was difficult to differentiate them from CMT. Combining age of onset, distal motor latency, and compound muscle action potential of the median nerve showed the optimal diagnostic performance to distinguish NIID from major CMT (AUC = 0.989, sensitivity = 92.6%, specificity = 97.4%). INTERPRETATION: Peripheral polyneuropathy is common in NIID. Our study suggest that nerve conduction study is useful to discriminate NIID.

Clinical and molecular genetic characteristics of 24 families of hereditary neuropathy with liability to pressure palsy and literature review. / é—ä¼ æ€§åŽ‹åŠ›æ˜“æ„Ÿæ€§å‘¨å›´ç¥žç»ç— 24ä¸ªå®¶ç³»çš„ä¸´åºŠå’Œåˆ†å­é—ä¼ å­¦ç‰¹å¾åŠæ–‡çŒ®å›žé¡¾.

OBJECTIVES: Hereditary neuropathy with liability to pressure palsy (HNPP) is a rare autosomal dominant peripheral neuropathy, usually caused by heterozygous deletion mutations in the peripheral myelin protein 22 (PMP22) gene. This study aims to investigate the clinical and molecular genetic characteristics of HNPP. METHODS: HNPP patients in the Department of Neurology at Third Xiangya Hospital of Central South University from 2009 to 2023 were included in this study. The general clinical data, nervous electrophysiological and molecular genetic examination results were collected and analyzed. Molecular genetic examination was to screen for deletion of PMP22 gene using multiplex ligation-dependent probe amplification (MLPA) after extracting genomic DNA from peripheral blood; and if no PMP22 deletion mutation was detected, next-generation sequencing was used to screen for PMP22 point mutations. The related literatures of HNPP were reviewed, and the clinical and molecular genetic characteristics of HNPP patients were analyzed. RESULTS: A total of 34 HNPP patients from 24 unrelated Chinese Han families were included in this study, including 25 males and 9 females. The average age at illness onset was 22.0 years. Sixty-two point five percent of the families had a positive family history. Among them, 30 patients had symptoms of peripheral nerve paralysis. Patients often presented with paroxysmal single limb weakness with (or) numbness (25/30), and some patients had paroxysmal unilateral recurrent laryngeal nerve (vagus nerve) paralysis (2/30). Physical examination revealed muscle weakness (23/29), hypoesthesia (9/29), weakened or absent ankle reflexes (20/29), distal limb muscle atrophy (8/29) and high arched feet (5/29). Most patients (26/30) could fully recover to normal after an acute attack. Thirty-one patients in our group underwent nervous electrophysiological examination, and showed multiple demyelinating peripheral neuropathies with both motor and sensory nerves involved. Most patients showed significantly prolonged distal motor latency (DML), mild to moderate nerve conduction velocity slowing, decreased amplitude of compound muscle action potential (CMAP) and sensory nerve action potential (SNAP), and sometimes with conduction block. Nerve motor conduction velocity was (48.5±5.5) m/s, and the CMAP amplitude was (8.4±5.1) mV. Nerve sensory conduction velocity was (37.4±10.5) m/s, and the SNAP amplitude was (14.4±15.2) µV. There were 24 families, 23 of whom had the classical PMP22 deletion, the last one had a heterozygous pathogenic variant in the PMP22 gene sequence (c.434delT). By reviewing clinical data and genetic testing results of reported 1 734 HNPP families, we found that heterozygous deletion mutation of PMP22 was the most common pathogenic mutation of HNPP (93.4%). Other patients were caused by PMP22 small mutations (4.0%), PMP22 heterozygous gross deletions (0.6%), and PMP22 complex rearrangements (0.1%). Thirty-eight sorts of HNPP-related PMP22 small mutations was reported, including missense mutations (10/38), nonsense mutations (4/38), base deletion mutations (13/38), base insertion mutations (3/38), and shear site mutations (8/38). HNPP patients most often presented with episodic painless single nerve palsy. Common peroneal nerve, ulnar nerve, and brachial plexus nerve were the most common involved nerves, accounting for about 75%. Only eighteen patients with cranial nerve involved was reported. CONCLUSIONS: Heterozygous deletion mutation of PMP22 is the most common pathogenic mutation of HNPP. Patients is characterized by episodic and painless peripheral nerve paralysis, mainly involving common peroneal nerve, ulnar nerve, and other peripheral nerves. Nervous electrophysiological examination has high sensitivity and specificity for the diagnosis of HNPP, which is manifested by extensive demyelinating changes. For patients with suspected HNPP, nervous electrophysiological examination and PMP22-MLPA detection are preferred. Sanger sequencing or next generation sequencing can be considered to detect other mutations of PMP22.

Expansion of Human-Specific GGC Repeat in Neuronal Intranuclear Inclusion Disease-Related Disorders.

Neuronal intranuclear inclusion disease (NIID) is a slowly progressing neurodegenerative disease characterized by eosinophilic intranuclear inclusions in the nervous system and multiple visceral organs. The clinical manifestation of NIID varies widely, and both familial and sporadic cases have been reported. Here we have performed genetic linkage analysis and mapped the disease locus to 1p13.3-q23.1; however, whole-exome sequencing revealed no potential disease-causing mutations. We then performed long-read genome sequencing and identified a large GGC repeat expansion within human-specific NOTCH2NLC. Expanded GGC repeats as the cause of NIID was further confirmed in an additional three NIID-affected families as well as five sporadic NIID-affected case subjects. Moreover, given the clinical heterogeneity of NIID, we examined the size of the GGC repeat among 456 families with a variety of neurological conditions with the known pathogenic genes excluded. Surprisingly, GGC repeat expansion was observed in two Alzheimer disease (AD)-affected families and three parkinsonism-affected families, implicating that the GGC repeat expansions in NOTCH2NLC could also contribute to the pathogenesis of both AD and PD. Therefore, we suggest defining a term NIID-related disorders (NIIDRD), which will include NIID and other related neurodegenerative diseases caused by the expanded GGC repeat within human-specific NOTCH2NLC.

Sensitivity of Sniffer Dogs for a Diagnosis of Parkinson's Disease: A Diagnostic Accuracy Study.

BACKGROUND: The diagnostic criteria for Parkinson's disease (PD) remain complex, which is especially problematic for nonmovement disorder experts. A test is required to establish a diagnosis of PD with improved accuracy and reproducibility. OBJECTIVE: The study aimed to investigate the sensitivity and specificity of tests using sniffer dogs to diagnose PD. METHODS: A prospective, diagnostic case-control study was conducted in four tertiary medical centers in China to evaluate the accuracy of sniffer dogs to distinguish between 109 clinically established medicated patients with PD, 654 subjects without PD, 37 drug-naïve patients with PD, and 185 non-PD controls. The primary outcomes were sensitivity and specificity of sniffer dog's identification. RESULTS: In the study with patients who were medicated, when two or all three sniffer dogs yielded positive detection results in a sample tested, the index test sensitivity, specificity, and positive and negative likelihood ratios were 91% (95% CI: 84%-96%), 95% (95% CI: 93%-97%), and 19.16 (95% CI: 13.52-27.16) and 0.10 (95% CI: 0.05-0.17), respectively. The corresponding sensitivity, specificity, and positive and negative likelihood ratios in patients who were drug-naïve were 89% (95% CI: 75%-96%), 86% (95% CI: 81%-91%), and 6.6 (95% CI: 4.51-9.66) and 0.13 (95% CI: 0.05-0.32), respectively. CONCLUSIONS: Tests using sniffer dogs may be a useful, noninvasive, fast, and cost-effective method to identify patients with PD in community screening and health prevention checkups as well as in neurological practice. © 2022 International Parkinson and Movement Disorder Society.

Genotype and phenotype distribution of 435 patients with Charcot-Marie-Tooth disease from central south China.

BACKGROUND AND PURPOSE: The purpose was to provide an overview of genotype and phenotype distribution in a cohort of patients with Charcot-Marie-Tooth disease (CMT) and related disorders from central south China. METHODS: In all, 435 patients were enrolled and detailed clinical data were collected. Multiplex ligation-dependent probe amplification for PMP22 duplication/deletion and CMT multi-gene panel sequencing were performed. Whole exome sequencing was further applied in the remaining patients who failed to achieve molecular diagnosis. RESULTS: Among the 435 patients, 216 had CMT1, 14 had hereditary neuropathy with pressure palsies (HNPP), 178 had CMT2, 24 had distal hereditary motor neuropathy (dHMN) and three had hereditary sensory and autonomic neuropathy (HSAN). The overall molecular diagnosis rate was 70%: 75.7% in CMT1, 100% in HNPP, 64.6% in CMT2, 41.7% in dHMN and 33.3% in HSAN. The most common four genotypes accounted for 68.9% of molecular diagnosed patients. Relatively frequent causes were missense changes in PMP22 (4.6%) and SH3TC2 (2.3%) in CMT1; and GDAP1 (5.1%), IGHMBP2 (4.5%) and MORC2 (3.9%) in CMT2. Twenty of 160 detected pathogenic variants and the associated phenotypes have not been previously reported. Broad phenotype spectra were observed in six genes, amongst which the pathogenic variants in BAG3 and SPTLC1 were detected in two sporadic patients presenting with the CMT2 phenotype. CONCLUSIONS: Our results provided a unique genotypic and phenotypic landscape of patients with CMT and related disorders from central south China, including a relatively high proportion of CMT2 and lower occurrence of PMP22 duplication. The broad phenotype spectra in certain genes have advanced our understanding of CMT.

The Phenotypic and Genetic Spectrum of Paroxysmal Kinesigenic Dyskinesia in China.

BACKGROUND: Paroxysmal kinesigenic dyskinesia is a spectrum of involuntary dyskinetic disorders with high clinical and genetic heterogeneity. Mutations in proline-rich transmembrane protein 2 have been identified as the major pathogenic factor. OBJECTIVES: We analyzed 600 paroxysmal kinesigenic dyskinesia patients nationwide who were identified by the China Paroxysmal Dyskinesia Collaborative Group to summarize the clinical phenotypes and genetic features of paroxysmal kinesigenic dyskinesia in China and to provide new thoughts on diagnosis and therapy. METHODS: The China Paroxysmal Dyskinesia Collaborative Group was composed of departments of neurology from 22 hospitals. Clinical manifestations and proline-rich transmembrane protein 2 screening results were recorded using unified paroxysmal kinesigenic dyskinesia registration forms. Genotype-phenotype correlation analyses were conducted in patients with and without proline-rich transmembrane protein 2 mutations. High-knee exercises were applied in partial patients as a new diagnostic test to induce attacks. RESULTS: Kinesigenic triggers, male predilection, dystonic attacks, aura, complicated forms of paroxysmal kinesigenic dyskinesia, clustering in patients with family history, and dramatic responses to antiepileptic treatment were the prominent features in this multicenter study. Clinical analysis showed that proline-rich transmembrane protein 2 mutation carriers were prone to present at a younger age and have longer attack duration, bilateral limb involvement, choreic attacks, a complicated form of paroxysmal kinesigenic dyskinesia, family history, and more forms of dyskinesia. The new high-knee-exercise test efficiently induced attacks and could assist in diagnosis. CONCLUSIONS: We propose recommendations regarding diagnostic criteria for paroxysmal kinesigenic dyskinesia based on this large clinical study of paroxysmal kinesigenic dyskinesia. The findings offered some new insights into the diagnosis and treatment of paroxysmal kinesigenic dyskinesia and might help in building standardized paroxysmal kinesigenic dyskinesia clinical evaluations and therapies. © 2020 International Parkinson and Movement Disorder Society.

Mutations in C1orf194, encoding a calcium regulator, cause dominant Charcot-Marie-Tooth disease.

Charcot-Marie-Tooth disease is a hereditary motor and sensory neuropathy exhibiting great clinical and genetic heterogeneity. Here, the identification of two heterozygous missense mutations in the C1orf194 gene at 1p21.2-p13.2 with Charcot-Marie-Tooth disease are reported. Specifically, the p.I122N mutation was the cause of an intermediate form of Charcot-Marie-Tooth disease, and the p.K28I missense mutation predominately led to the demyelinating form. Functional studies demonstrated that the p.K28I variant significantly reduced expression of the protein, but the p.I122N variant increased. In addition, the p.I122N mutant protein exhibited the aggregation in neuroblastoma cell lines and the patient's peroneal nerve. Either gain-of-function or partial loss-of-function mutations to C1ORF194 can specify different causal mechanisms responsible for Charcot-Marie-Tooth disease with a wide range of clinical severity. Moreover, a knock-in mouse model confirmed that the C1orf194 missense mutation p.I121N led to impairments in motor and neuromuscular functions, and aberrant myelination and axonal phenotypes. The loss of normal C1ORF194 protein altered intracellular Ca2+ homeostasis and upregulated Ca2+ handling regulatory proteins. These findings describe a novel protein with vital functions in peripheral nervous systems and broaden the causes of Charcot-Marie-Tooth disease, which open new avenues for the diagnosis and treatment of related neuropathies.

[Research advance of underlying pathogenesis and target therapies in Charcot-Marie-Tooth disease type 1A].

Charcot-Marie-Tooth disease (CMT) is the commonest form of inherited neuropathy and has an incidence of 1/2500. CMT1A is the commonest subtype of CMT, which is caused by duplication of peripheral myelin protein 22 (PMP22) gene and accounts for approximately 50% of CMT diagnosed by genetic testing. Duplication of PMP22 may influence the production of PMP22 mRNA and protein, and interfere with the proliferation, differentiation and apoptosis of Schwann cells. In addition, deregulation of NRG1/ErbB pathway and lipid metabolism can also lead to dysfunction of Schwann cells. Such factors may disturb the myelination process, leading to axon degeneration, muscle weakness, and atrophy subsequently. Accordingly, drug therapies for CMT1A are developed by targeting such factors. PXT3003, antisense oligonucleotides (ASOs) and small interfering RNA (siRNA) are supposed to down-regulate the level of PMP22 mRNA, while recombinant human NRG-1 (rhNRG1) and neurotrophin-3 (NT-3) may enhance Schwann cells survival and differentiation. In addition, lipid-supplemented diet may remedy the defect of lipid metabolism and maintain the proper structure of myelin. Other targeting drugs include ascorbic acid, progesterone antagonists, IFB-088, ADX71441, and ACE-083. This review is to sum up the pathogenesis of CMT1A and promising targeting drug therapies for further research.

A novel WARS mutation (p.Asp314Gly) identified in a Chinese distal hereditary motor neuropathy family.

Distal hereditary motor neuropathy (dHMN) is a clinically and genetically heterogeneous group of inherited neuropathies characterized by distal limb muscle wasting and weakness with no or minimal sensory abnormalities. To investigate the clinical and genetic features of dHMN caused by WARS mutations in mainland China, we performed Sanger sequencing of the coding and untranslated region (UTR) regions of WARS in 160 unresolved dHMN and Charcot-Marie-Tooth (CMT) index patients. We detected a novel heterozygous variant c.941A>G (p.Asp314Gly) of WARS in an index patient from an autosomal dominant dHMN family including five affected members over three generations. The variant completely co-segregates with the dHMN phenotype in the family, and it was classified as likely pathogenic according to the American College of Medical Genetics and Genomics standards and guidelines. The clinical features included juvenile to adult onset (15-23 years), distal wasting and weakness, minimal sensory disturbance and length-dependent motor axonal degeneration with CMT examination score ranging from 6 to 10. Our report further confirms the role of WARS in dHMN and indicates that the variant c.941A>G (p.Asp314Gly) of WARS is related to a mild to moderate affected and later onset phenotype of dHMN.

Guillain-Barré syndrome in southern China: retrospective analysis of hospitalised patients from 14 provinces in the area south of the Huaihe River.

OBJECTIVES: The clinical and epidemiological profiles of Guillain-Barré syndrome (GBS) in southern China have yet to be fully recognised. We aimed to investigate the subtypes of GBS in southern China, compare the clinical features of demyelinating form with that of axonal form and test whether preceding infections and age have influence on the clinical phenotype, disease course and severity of GBS. METHODS: Medical records of patients with a diagnosis of GBS admitted to 31 tertiary hospitals, located in 14 provinces in southern China, from 1 January 2013 to 30 September 2016, were collected and retrospectively reviewed. RESULTS: Finally. 1056 patients, including 887 classic GBS and 169 variants, were enrolled. The 661 classic patients with available electromyographic data were grouped as having acute inflammatory demyelinating polyneuropathy (AIDP, 49.0%), acute motor axonal neuropathy (AMAN, 18.8%), inexcitable (0.9%) and equivocal (31.3%). In contrast to AIDP, patients with AMAN were characterised by earlier nadir (P=0.000), higher Hughes score at nadir (P=0.003) and at discharge (P=0.000). Preceding upper respiratory infections were identified in 369 (34.9%) patients, who were more inclined to develop AIDP (P=0.000) and Miller-Fisher syndrome (P=0.027), whereas gastrointestinal infection were found in 89 (8.4%) patients, who were more prone to develop AMAN (P=0.000), with more severe illness (P=0.001) and longer hospital stay (P=0.009). Children (≤15 years) and the elderly (≥56 years) were more severe at nadir, the elderly had the longest hospital stay (P=0.023). CONCLUSION: AIDP is the predominant form in southern China, which is different from data of northern China. The different subtypes, preceding infection and age of onset can partially determine the disease progression, severity and short-term recovery speed of GBS. CLINICAL TRIAL REGISTRATION: ChiCTR-RRC-17014152.

MFN2-related genetic and clinical features in a cohort of Chinese CMT2 patients.

Charcot-Marie-Tooth disease 2A (CMT2A), caused by mutations in the mitofusin 2 gene (MFN2), is the most common CMT2 subtype. The aim of our study is to assess the frequency and summarize the genetic and clinical characteristics of Chinese CMT2A patients. A total of 17 coding exons of MFN2 were detected by direct sequencing in 82 unrelated Chinese families diagnosed as CMT2. Clinical evaluations were analyzed among CMT2A patients. We identified 14 missense variants in 9 sporadic and 6 familial cases, including four novel mutations (T129A, S249F, Q367P, and Q674L), 4 known mutations (R94W, R94Q, T105M, C132Y, M376V and Q751X), and 4 rare missense variants (K120E, C217F, K307E and T356S). A total of 23 patients had early-onset phenotype. Two patients had a CMTNS score of 0 to 10; 16 had a score of 11 to 20; and 7 had a score greater than 20. Five patients were confirmed a de novo origin. Six of 14 variants were located or closed to the GTPase domain. We report four novel mutations and four rare missense variants. MFN2 mutations account for 18% of CMT2 families in mainland China. The common characteristics of Chinese pedigree are early disease onset and moderate phenotypes.

PMP22-Related neuropathies and other clinical manifestations in Chinese han patients with charcot-marie-tooth disease type 1.

INTRODUCTION: Most cases of Charcot-Marie-Tooth (CMT) disease are caused by mutations in the peripheral myelin protein 22 gene (PMP22), including heterozygous duplications (CMT1A), deletions (HNPP), and point mutations (CMT1E). METHODS: Single-nucleotide polymorphism (SNP) arrays were used to study PMP22 mutations based on the results of multiplex ligation-dependent probe amplification (MLPA) and polymerase chain reaction-restriction fragment length polymorphism methods in 77 Chinese Han families with CMT1. PMP22 sequencing was performed in MLPA-negative probands. Clinical characteristics were collected for all CMT1A/HNPP probands and their family members. RESULTS: Twenty-one of 77 CMT1 probands (27.3%) carried duplication/deletion (dup/del) copynumber variants. No point mutations were detected. SNP array and MLPA seem to have similar sensitivity. Fifty-seven patients from 19 CMT1A families had the classical CMT phenotype, except for 1 with concomitant CIDP. Two HNPP probands presented with acute ulnar nerve palsy or recurrent sural nerve palsy, respectively. CONCLUSIONS: The SNP array has wide coverage, high sensitivity, and high resolution and can be used as a screening tool to detect PMP22 dup/del as shown in this Chinese Han population.

Association between weekend catch-up sleep and depression of the United States population from 2017 to 2018: A cross-sectional study.

Insufficient sleep on weekdays has become a societal norm, and studies have shown that sleep deprivation increases the risk of depression. Although individuals often resort to weekend catch-up sleep (CUS) as a compensatory measure, the present evidence supporting its efficacy in mitigating the risk of depression is limited. This article attempts to explore the relationship between CUS and depression. In this study, a total of 5510 participants were included, characterized into two groups: nondepressed (n = 5051) and depressed (n = 459), with data extracted from the National Health and Nutrition Examination Survey (NHANES). Compared with people without CUS, those practicing CUS exhibited a significantly lower risk of depression (OR = 0.81, P = 0.048). In subgroup analysis, this reduction effect was only observed in males (OR = 0.70, 95 % CI 0.05 to 0.99, P = 0.04), middle-aged (>40, ≤60) (OR: 0.57, 95 % CI: 0.40 to 0.81, P = 0.002), married or living with parents (OR: 0.61, 95 % CI: 0.44 to 0.86, P = 0.004), groups with three or more family members (OR: 0.69, 95 % CI: 0.52 to 0.93, P = 0.01), and individuals without alcohol intake (OR: 0.24,95 % CI: 0.09 to 0.67, P = 0.006). Therefore, in the realm of depression treatment, doctors may consider advising patients to get adequate sleep on weekends as part of their overall treatment plan. At the same time, individuals can also choose weekend sleep as a proactive strategy for regulating their psychological status.

Phenotype-driven reanalysis reveals five novel pathogenic variants in 40 exome-negative families with Charcot-Marie-Tooth Disease.

BACKGROUND: To identify genetic causes in 40 whole exome sequencing (WES)-negative Charcot-Marie-Tooth (CMT) families and provide a summary of the clinical and genetic features of the diagnosed patients. METHODS: The clinical information and sequencing data of 40 WES-negative families out of 131 CMT families were collected, and phenotype-driven reanalysis was conducted using the Exomiser software. RESULTS: The molecular diagnosis was regained in 4 families, increasing the overall diagnosis rate by 3.0%. One family with adolescent-onset pure CMT1 was diagnosed [POLR3B: c.2810G>A (p.R937Q)] due to the novel genotype-phenotype association. One infantile-onset, severe CMT1 family with deep sensory disturbance was diagnosed by screening the BAM file and harbored c.1174C>T (p.R392*) and 875_927delinsCTGCCCACTCTGCCCACTCTGCCCACTCTG (p.V292Afs53) of PRX. Two families were diagnosed due to characteristic phenotypes, including an infantile-onset ICMT family with renal dysfunction harboring c.213_233delinsGAGGAGCA (p.S72Rfs34) of INF2 and an adolescent-onset CMT2 family with optic atrophy harboring c.560C>T (p.P187L) and c.616A>G (p.K206E) of SLC25A46. According to the American College of Medical Genetics and Genomics (ACMG) guidelines, the variants of POLR3B and SLC25A46 were classified as likely pathogenic, and the variants of INF2 and PRX were pathogenic. All these variants were first reported worldwide except for p.R392* of PRX. CONCLUSIONS: We identified five novel pathogenic variants in POLR3B, PRX, INF2, and SLC25A46, which broaden their phenotypic and genotypic spectrums. Regular phenotype-driven reanalysis is a powerful strategy for increasing the diagnostic yield of WES-negative CMT patients, and long-term follow-up and screening BAM files for contiguous deletion and missense variants are both essential for reanalysis.