Clinical and molecular insights into A97S variants in hereditary transthyretin amyloid polyneuropathy in South China.

OBJECTIVE: This study aims to delineate the clinical profiles of the hereditary transthyretin amyloid polyneuropathy (ATTRv-PN) patients with A97S variant from southern China and the molecular characteristics of this mutant protein. METHODS: Fifteen ATTRv-PN patients with heterozygous A97S and one patient with homozygous A97S were included in the study. Serum TTR tetramer concentration was quantified through ultra-performance liquid chromatography. Stabilities of A97S-TTR were assessed through in vitro urea-mediated tryptophan fluorescence experiments, and nephelometry was employed in drug response assessment. RESULTS: All patients were late-onset (≥50 years) with a mean age of onset at 59.26 ± 5.06 years old. Patients displayed a mixed phenotype featuring sensory-motor neuropathy with autonomic dysfunction and cardiac involvement, such as palpitations and chest pain. Electrophysiological studies showed generally axonal impairment of sensory and motor nerves. Tafamidis-treated patients showed significantly higher TTR tetramer concentrations, approaching healthy controls' levels. In vitro assessment showed that A97S-TTR was more kinetically stable than the V122I-TTR, and tetramer stabilisers inhibited A97S-TTR amyloid formation by more than 70%. CONCLUSION: This study provides valuable insights into the clinical and molecular characteristics of ATTRv-PN patients with A97S from South China, particularly regarding the differences in disease progression and stability features.

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.

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.

Metagenomic next-generation sequencing of cell-free DNA for the identification of viruses causing central nervous system infections.

IMPORTANCE: This study provides significant new data on the application of metagenomic next-generation sequencing (mNGS) to clinical diagnostics of central nervous system (CNS) viral infections, which can have high mortality rates and severe sequelae. Conventional diagnostic procedures for identifying viruses can be inefficient and rely on preconceived assumptions about the pathogen, making mNGS an appealing alternative. However, the effectiveness of mNGS is affected by the presence of human DNA contamination, which can be minimized by using cell-free DNA (cfDNA) instead of whole-cell DNA (wcDNA). This multi-center retrospective study of patients with suspected viral CNS infection found that mNGS using cfDNA had a significantly lower proportion of human DNA and higher sensitivity for detecting viruses than mNGS using wcDNA. Herpesviruses, particularly VZV, were found to be the most common DNA viruses in these patients. Overall, mNGS using cfDNA is a promising complementary diagnostic method for detecting CNS viral infections.

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.

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.

The genetic and clinical spectrum in a cohort of 39 families with complex inherited peripheral neuropathies.

With complicated conditions and a large number of potentially causative genes, the diagnosis of a patient with complex inherited peripheral neuropathies (IPNs) is challenging. To provide an overview of the genetic and clinical features of 39 families with complex IPNs from central south China and to optimize the molecular diagnosis approach to this group of heterogeneous diseases, a total of 39 index patients from unrelated families were enrolled, and detailed clinical data were collected. TTR Sanger sequencing, hereditary spastic paraplegia (HSP) gene panel, and dynamic mutation detection in spinocerebellar ataxia (SCAs) were performed according to the respective additional clinical features. Whole-exome sequencing (WES) was used in patients with negative or unclear results. Dynamic mutation detection in NOTCH2NLC and RCF1 was applied as a supplement to WES. As a result, an overall molecular diagnosis rate of 89.7% was achieved. All 21 patients with predominant autonomic dysfunction and multiple organ system involvement carried pathogenic variants in TTR, among which nine had c.349G > T (p.A97S) hotspot variants. Five out of 7 patients (71.4%) with muscle involvement harbored biallelic pathogenic variants in GNE. Five out of 6 patients (83.3%) with spasticity reached definite genetic causes in SACS, KIF5A, BSCL2, and KIAA0196, respectively. NOTCH2NLC GGC repeat expansions were identified in all three cases accompanied by chronic coughing and in one patient accompanied by cognitive impairment. The pathogenic variants, p.F284S and p.G111R in GNE, and p.K4326E in SACS, were first reported. In conclusion, transthyretin amyloidosis with polyneuropathy (ATTR-PN), GNE myopathy, and neuronal intranuclear inclusion disease (NIID) were the most common genotypes in this cohort of complex IPNs. NOTCH2NLC dynamic mutation testing should be added to the molecular diagnostic workflow. We expanded the genetic and related clinical spectrum of GNE myopathy and ARSACS by reporting novel variants.