Here, we conducted temporal RNA sequencing (RNA-seq) profiling of human induced pluripotent stem cells (hiPSCs) and induced pluripotent stem cell (iPSC)-derived motor neurons (iMNs) carrying C9orf72, FUS, TARDBP, or SOD1 mutations in both patients with amyotrophic lateral sclerosis (ALS) and healthy individuals. We discovered dysregulated gene expression and alternative splicing (AS) throughout iMN development and maturation, and iMNs with mutations in ALS-associated genes displayed enrichment of cytoskeletal defects and synaptic alterations from the premature stage to mature iMNs. Our findings indicate that synaptic gene dysfunction is a common molecular hallmark of familial ALS, which may result in neuronal susceptibility and progressive motor neuron degeneration. Analysis of upstream splicing factors revealed that differentially expressed RNA-binding proteins (RBPs) in iMNs from patients with ALS may cause abnormal AS events. Overall, our research provides a comprehensive and valuable resource for gaining insights into the shared mechanisms of familial ALS pathogenesis during motor neuron development and maturation in iMN models.
Background Amyotrophic lateral sclerosis (ALS) is a severe motor neuron disease, with highly diverse survival time. However, genetic and epigenetic factors influencing ALS survival across diverse populations remain unclear. Methods We performed whole-genome sequencing (WGS) and DNA methylome array in blood DNA of patients with ALS. For survival analysis, we used Cox proportional hazards model for genetic variants, DNA methylation (DNAm) of CpG sites or CpG-SNPs in Chinese and Canadian cohorts, followed by meta-analysis. We performed pathway enrichment analysis for candidate genes inferred from DNAm events associated with survival. In paired genome and methylome data, we analysed the effect of the candidate CpG-SNP genotypes on DNAm status. Findings Genome-wide cross-population meta-analysis of common variants in 511 patients with ALS showed a suggestive association of CAV1/CAV2 rs117002347 genotypes with survival. Epigenome-wide cross-population meta-analysis in 459 patients revealed that ALS survival was significantly linked to DNAm of 88 CpGs on 40 genes, and highlighted the AMPK and cytoskeleton pathways. Epigenome-wide cross-population meta-analysis of CpG-SNPs in 459 patients identified 8 loci on 4 genes, including BAG6 (cg27014438/rs28732154), which was further validated in another 204 patients with ALS. Moreover, analysis of paired genome/epigenome data (n = 454) indicated that BAG6 rs28732154 genotypes may modulate cg27014438 methylation, which is also a cis-eQTM of BAG6 expression in blood. Interpretation Our study identified BAG6 cg27014438 methylation as a potential epigenetic modifier of ALS survival. BAG6 cg27014438 methylation is modulated by rs28732154 genotypes, and linked to BAG6 expression. Our findings extended our understanding of epigenetic modifiers in ALS survival. Funding This work was supported by the National Natural Science Foundation of China (82071430, 82371878) (MZ), Shanghai Municipal Natural Science Foundation General Program (22ZR1466400) (MZ), the Fundamental Research Funds for the Central Universities (MZ), the G. Harry Sheppard Memorial Research Fund, and Canadian Consortium on Neurodegeneration in Aging (ER).
Amyotrophic lateral sclerosis (ALS) is a severe motor neuron disease with uncertain genetic predisposition in most sporadic cases. The spatial architecture of cell types and gene expression are the basis of cell-cell interactions, biological function and disease pathology, but are not well investigated in the human motor cortex, a key ALS-relevant brain region. Recent studies indicated single nucleus transcriptomic features of motor neuron vulnerability in ALS motor cortex. However, the brain regional vulnerability of ALS-associated genes and the genetic link between region-specific genes and ALS risk remain largely unclear.Here, we developed an entropy-weighted differential gene expression matrix-based tool (SpatialE) to identify the spatial enrichment of gene sets in spatial transcriptomics. We benchmarked SpatialE against another enrichment tool (multimodal intersection analysis) using spatial transcriptomics data from both human and mouse brain tissues. To investigate regional vulnerability, we analysed three human motor cortex and two dorsolateral prefrontal cortex tissues for spatial enrichment of ALS-associated genes. We also used Cell2location to estimate the abundance of cell types in ALS-related cortex layers. To dissect the link of regionally expressed genes and ALS risk, we performed burden analyses of rare loss-of-function variants detected by whole-genome sequencing in ALS patients and controls, then analysed differential gene expression in the TargetALS RNA-sequencing dataset.SpatialE showed more accurate and specific spatial enrichment of regional cell type markers than multimodal intersection analysis in both mouse brain and human dorsolateral prefrontal cortex. Spatial transcriptomic analyses of human motor cortex showed heterogeneous cell types and spatial gene expression profiles. We found that 260 manually curated ALS-associated genes are significantly enriched in layer 5 of the motor cortex, with abundant expression of upper motor neurons and layer 5 excitatory neurons. Burden analyses of rare loss-of-function variants in Layer 5-associated genes nominated NOMO1 as a novel ALS-associated gene in a combined sample set of 6814 ALS patients and 3324 controls (P = 0.029). Gene expression analyses in CNS tissues revealed downregulation of NOMO1 in ALS, which is consistent with a loss-of-function disease mechanism. In conclusion, our integrated spatial transcriptomics and genomic analyses identified regional brain vulnerability in ALS and the association of a layer 5 gene (NOMO1) with ALS risk. Using spatial transcriptomics and single-nucleus RNA sequencing, Guo et al. show that ALS-associated gene expression is enriched in layer 5 of the motor cortex. Genomic analyses revealed a novel association between a layer 5 gene called NOMO1 and ALS risk. Understanding region-specific vulnerability in ALS will aid precision medicine approaches.
Objectives. Tube feeding is an effective way to provide nutritional support for amyotrophic lateral sclerosis (ALS) patients with severe dysphagia. Currently, the predictors of tube feeding and the survival affected by tube feeding were poorly studied in Chinese ALS patients. Therefore, we aimed to explore predictive factors and establish a prediction model to quantitatively predict the risk of tube feeding. Furthermore, we explored the survival benefit provided by tube feeding. Methods. In this longitudinal, prospective cohort study, we included patients diagnosed with ALS using the Awaji criteria at the ALS clinic in Huashan Hospital. Follow-up was conducted by telephone interview from January 1, 2019, to December 30, 2021, or until death. All statistical analyses were performed using R software. Results. Overall, 218 patients were recruited for the study. The multivariate Cox regression analysis showed a high ALSFRS-R slope (adjusted hazard ratio aHR = 4.94 (95% confidence interval (95% CI: 2.26-10.81), p < 0.001 ), low bulbar score ( aHR = 0.81 (95% CI: 0.69-0.96), p = 0.01 ), history of ischemic stroke ( aHR = 5.69 (95% CI: 1.3-24.82), p = 0.02 ), and bulbar involvement ( aHR = 11.87 (95% CI: 1.42-99.31), p = 0.02 ) as independent risk factors of tube feeding. The nomogram model was established with moderate discrimination and calibration. Among 71 ALS patients with tube feeding indication, 33.8% accepted gastrostomy suggestion and 14.1% had nasogastric tube (NGT) insertion. However, gastrostomy and NGT did not accelerate disease progression ( aHR = 0.57 (95% CI: 0.20-1.67), p = 0.31 and aHR = 1.72 (95% CI: 0.43-6.88), p = 0.43 , respectively). Conclusions. We developed a nomogram that could be a prediction tool to predict individual timing of tube feeding for ALS patients. In addition, we found that gastrostomy and NGT did not affect ALS patients’ survival.
Objective: Genetic mutations of fused in sarcoma (FUS) causing amyotrophic lateral sclerosis (ALS) may disrupt mRNA splicing events. For example, the FUS c.1394-2delA variant was reported in two western ALS patients, but its molecular mechanism is unclear. In this study, we aim to investigate FUS splice site mutations in Chinese ALS patients. Methods: Sanger sequencing was used to identify FUS splicing mutations in Chinese ALS patients. We combined a deep learning tool (SpliceAI), RNA sequencing, and RT-PCR/RT-qPCR to analyze the effect of FUS c.1394-2delA mutation on RNA splicing and expression. AlphaFold was used to predict the protein structure of mutant FUS. In transfected cell lines, we used immunofluorescence to assess cytoplasmicmislocalization of mutant FUS protein. Results: We identified a de novo FUS splice acceptor site mutation (c.1394-2delA, p. Gly466Valfs*14) in one Chinese sporadic ALS patient, which is linked to exon 14 skipping, and upregulated total FUS mRNA expression. The FUS splice site mutation was predicted to be translated into a truncated protein product at Cterminal. In vitro studies revealed that the FUS mutation increased cytoplasmic mislocalization in both HEK293T and SH-SY5Y cells. Conclusions: We identified a de novo FUS splicing mutation (c.1394-2delA, p. Gly466Valfs*14) in 1 out of 233 Chinese ALS patients. It caused abnormal RNA splicing, upregulated gene expression, truncated FUS translation, and cytosolic mislocalization. Our findings suggested that FUS splice site mutation is rare in Chinese ALS patients and extended our knowledge of molecular mechanisms of the FUS c.1394-2delA mutation.
AIM:To clarify the role of Eomesodermin (EOMES) to serve as a disease-relevant biomarker and the intracellular molecules underlying the immunophenotype shifting of CD4+T subsets in amyotrophic lateral sclerosis (ALS).METHODS:The derivation and validation cohorts included a total of 148 ALS patients and 101 healthy controls (HCs). Clinical data and peripheral blood were collected. T-cell subsets and the EOMES expression were quantified using multicolor flow cytometry. Serum neurofilament light chain (NFL) was measured. In 1-year longitudinal follow-ups, the ALSFRS-R scores and primary endpoint events were further recorded in the ALS patients of the validation cohort.RESULTS:In the derivation cohort, the CD4+EOMES+T-cell subsets were significantly increased (p < 0.001). EOMES+ subset was positively correlated with increased serum NFL levels in patients with onset longer than 12 months. In the validation cohort, the elevated CD4+EOMES+T-cell proportions and their association with NFL levels were also identified. The longitudinal study revealed that ALS patients with higher EOMES expression were associated with higher progression rates (p = .010) and worse prognosis (p = .003).CONCLUSIONS:We demonstrated that increased CD4+EOMES+T-cell subsets in ALS were associated with disease progression and poor prognosis. Identifying these associations may contribute to a better understanding of the immunopathological mechanism of ALS.
Objectives To explore whether the combined analysis of motor and bulbar region of M1 on susceptibility-weighted imaging (SWI) can be a valid biomarker for amyotrophic lateral sclerosis (ALS). Methods Thirty-two non-demented ALS patients and 35 age- and gender-matched healthy controls (HC) were retrospectively recruited. SWI and 3D-T1-MPRAGE images were obtained from all individuals using a 3.0-T MRI scan. The bilateral posterior band of M1 was manually delineated by three neuroradiologists on phase images and subdivided into the motor and bulbar regions. We compared the phase values in two groups and performed a stratification analysis (ALSFRS-R score, duration, disease progression rate, and onset). Receiver operating characteristic (ROC) curves were also constructed. Results ALS group showed significantly increased phase values in M1 and the two subregions than the HC group, on the all and elderly level ( p < 0.001, respectively). On all-age level comparison, negative correlations were found between phase values of M1 and clinical score and duration ( p < 0.05, respectively). Similar associations were found in the motor region ( p < 0.05, respectively). On both the total ( p < 0.01) and elderly ( p < 0.05) levels, there were positive relationships between disease progression rate and M1 phase values. In comparing ROC curves, the entire M1 showed the best diagnostic performance. Conclusions Combining motor and bulbar analyses as an integral M1 region on SWI can improve ALS diagnosis performance, especially in the elderly. The phase value could be a valuable biomarker for ALS evaluation. Key Points • Integrated analysis of the motor and bulbar as an entire M1 region on SWI can improve the diagnosis performance in ALS. • Quantitative analysis of iron deposition by SWI measurement helps the clinical evaluation, especially for the elderly patients. • Phase value, when combined with the disease progression rate, could be a valuable biomarker for ALS.
Background Pathogenic mutations in the TANK-binding kinase 1 ( TBK1 ) gene have been associated with progressive supranuclear palsy (PSP)-like extrapyramidal symptoms, amyotrophic lateral sclerosis (ALS), as well as cognitive and behavioral alterations. However, the question as to whether TBK1 mutations may be associated with tau burden remains unanswered. Methods To investigate whether patients presenting with PSP-like extrapyramidal symptoms caused by TBK1 mutations have evidence of tau deposition as reflected by positive 18 F-APN-1607 tau PET imaging findings. Four patients who showed PSP-like extrapyramidal symptoms, ALS, and cognitive/behavioral alterations were consecutively enrolled between August 2019 and August 2020. Patients underwent TBK1 gene sequencing and 18 F-APN-1607 tau PET imaging. All PET images were interpreted in a blinded fashion with respect to genetic results. Brain structural changes were investigated with MRI, whereas 11 C-CFT or 18 F-DTBZ PET imaging was performed to identify dopaminergic degeneration. Results Pathogenic TBK1 mutations were identified in three of the four study patients. The three mutation carriers – but not the case without – showed positive 18 F-APN-1607 binding in PSP-related regions, suggesting the presence of tau pathology. Mesencephalic atrophy (hummingbird sign) was observed in all TBK1 mutation carriers, and two of them also had evidence of frontotemporal atrophy. Dopaminergic degeneration was evident in all cases, regardless of TBK1 mutations. Conclusions Pathogenic TBK1 mutations in patients with PSP-like extrapyramidal symptoms are associated with positive 18 F-APN-1607 tau PET imaging findings. Our data should prompt additional investigations on the potential role of tau accumulation in the pathogenesis of disease conditions associated with TBK1 mutations.
This case report describes a woman whose diagnosis of frontotemporal lobar degeneration-motor neuron disease involved evidence on positron emission tomography of dopaminergic damage to the caudate.
Many studies reported that ERP-based BCIs can provide communication for some people with amyotrophic lateral sclerosis (ALS). ERP-based BCIs often present characters within a matrix that occupies the center of the visual field. However, several studies have identified some concerns with the matrix-based approach. This approach may lead to fatigue and errors resulting from flashing adjacent stimuli, and is impractical for users who might want to use the BCI in tandem with other software or feedback in the center of the monitor. In this paper, we introduce and validate an alternate ERP-based BCI display approach. By presenting stimuli near the periphery of the display, we reduce the adjacency problem and leave the center of the display available for feedback or other applications. Two ERP-based display approaches were tested on 18 ALS patients to: (1) compare performance between a conventional matrix speller paradigm (Matrix-P, mean visual angle 6°) and a new speller paradigm with peripherally distributed stimuli (Peripheral-P, mean visual angle 8.8°); and (2) assess performance while spelling 42 characters online continuously, without a break. In the Peripheral-P condition, 12 subjects attained higher than 80% feedback accuracy during online performance, and 7 of these subjects obtained higher than 90% accuracy. The experimental results showed that the Peripheral-P condition yielded performance comparable to the conventional Matrix-P condition (p > 0.05) in accuracy and information transfer rate. This paper introduces a new display approach that leaves the center of the monitor open for feedback and/or other display elements, such as movies, games, art, or displays from other AAC software or conventional software tools.
Amyotrophic lateral sclerosis (ALS) is the most common adult-onset motor neuron disease characterized by the formation of protein inclusion and progressive loss of motor neurons, finally leading to muscle weakness and respiratory failure. So far, the effective drugs for ALS are yet to be developed. Impairment of transcriptional activator transcription factor EB (TFEB) has been demonstrated as a key element in the pathogenesis of ALS. Trehalose is an mechanistic target of rapamycin-independent inducer for autophagy, which showed autophagic activation and neuroprotective effect in a variety of neurodegenerative diseases. The mechanism for trehalose-induced autophagy enhancement is not clear, and its therapeutic effect on TAR DNA-binding protein-43 (TDP-43) proteinopathies has been poorly investigated. Here we examined the effect of trehalose on TDP-43 clearance in a cell culture model and identified that trehalose treatment significantly reduced TDP-43 accumulation in vitro through modulation of the autophagic degradation pathway. Further studies revealed that activation of TFEB induced by trehalose was responsible for the enhancement of autophagy and clearance of TDP-43 level. These results gave us the notion that TFEB is a central regular in trehalose-mediated autophagic clearance of TDP-43 aggregates, representing an important step forward in the treatment of TDP-43 related ALS diseases.
OBJECTIVES:To explore the sensitivity of potential DTI-based biomarkers in detecting microstructural changes for whole-brain white matter in early stage amyotrophic lateral sclerosis (ALS), analyze the relationship between the DTI indices and disease status, and further clarify potential brain regions for disease monitoring and clinical assessment.METHODS:Thirty-three non-demented ALS patients and 32 age- and gender-matched subjects participated in this study. DTI data were acquired via 3.0T MRI scanner. Maps of diffusion-related indices including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) were obtained. Tract-based spatial statistics (TBSS) were used to investigate whole-brain white matter changes of each index. Correlation analyses between both brain-wide and volume-of-interest (VOI)-wide white matter alterations and clinical factors including ALSFRS-R scores, disease duration, and progression rate were performed.RESULTS:Compared to healthy subjects, ALS patients showed significantly increased RD, MD and reduced FA, mainly along the corticospinal tract (CST) and the body of corpus callosum (CC). Increases in RD were broader than decreases in FA, in CST of both hemispheres. Meanwhile, involvement of several extra-motor regions was also revealed by RD. Significant positive correlation between ALSFRS-R scores and FA, negative correlation between ALSFRS-R and RD were found in left CST.CONCLUSIONS:RD may be the most sensitive biomarker for the detection of early demyelination of white matter. Both RD and FA may serve as objective biomarkers for disease severity assessment. CST may be the most affected brain region in non-demented ALS.KEY POINTS:• Changes in RD were broader than those in FA in bilateral CST. • Involvement of extra-motor regions was uncovered by RD. • FA and RD in CST were related to ALSFRS-R scores.
The mutation of vesicle-associated membrane protein-associated protein B (VAPB) was proved to cause family amyotrophic lateral sclerosis (FALS). Only two mutations of VAPB associated with ALS have been reported (p.Pro56Ser and p.Thr46Ile). Here we reported a Chinese Han FALS family caused by a novel VAPB point mutation. The clinical materials of one Chinese Han FALS family were collected. The genetic analysis was carried out by target sequencing and further verified by Sanger sequencing. One novel mutation of c.167C>A (p.Pro56His) on VAPB was found in the proband. The age at onset of the proband was 48 with the onset symptoms of weakness in the right arm, followed by progressive limb and trunk weakness with decreased deep-tendon reflexes, muscular cramps and fasciculation. But the disease duration was more than 15 years. He was under the tracheotomy for 1 year at last visit. Electromyography showed widespread acute and chronic neurogenic damages. His mother presented weakness in her limbs in 50 s and died 15 years later. One of his younger sisters diagnosed as ALS for 6 years also carried the same mutation. She presented the similar symptoms on 41. No dominant upper motor neuron sign was showed. The clinical features were similar to the patients carrying the known mutation of p.Pro56Ser. A novel mutation of VAPB was found in one Chinese Han FALS pedigree. The affected patients presented a much slower progression and the lesions were limited in lower motor neurons.
Objective: Amyotrophic lateral sclerosis (ALS) is a rare disease, but is also one of the most common motor neuron diseases, and people of all races and ethnic backgrounds are affected. There is currently no cure. Brain computer interfaces (BCIs) can establish a communication channel directly between the brain and an external device by recognizing brain activities that reflect user intent. Therefore, this technology could help ALS patients in promoting functional independence through BCI-based speller systems and motor assistive devices. Methods: In this paper, two kinds of ERP-based speller systems were tested on 18 ALS patients to: (1) assess performance when they spelled 42 characters online continuously, without a break; and (2) to compare performance between a matrix-based speller paradigm (MS-P, mean visual angle 6 degree) and a new speller paradigm that used a larger visual angle called the large visual angle speller paradigm (LS-P, mean visual angle 8 degree). Results: Although results showed that there were no significant differences between the two paradigms in accuracy trend over continuous use (p>0.05), the fatigue during the LS-P condition was significantly lower than that of MS-P (p<0.05). Results also showed that continuous use slightly reduced the performance of this ERP-based BCI. Conclusion: 15 subjects obtained higher than 80% feedback accuracy (online output accuracy) and 9 subjects obtained higher than 90% feedback accuracy in one of the two paradigms, thus validating the BCI approaches in this study. Significance: Most ALS subjects in this study could spell effectively after continuous use of an ERP-based BCI. The new LS-P display may be easier for subjects to use, resulting in lower fatigue.
Objectives To investigate functional cerebral abnormalities in patients with amyotrophic lateral sclerosis (ALS) using functional magnetic resonance imaging (fMRI) during action observation. Methods Thirty patients with ALS and 30 matched healthy controls underwent fMRI with an experimental paradigm while observing a video of repetitive flexion-extension of the fingers at three frequency levels or three complexity levels, alternated with periods of a static hand. A parametric analysis was applied to determine the effects of each of the two factors. Results Action observation activated similar neural networks as the research on execution of action in the ALS patients and healthy subjects in several brain regions related to the mirror-neuron system (MNS). In the ALS patients, in particular, the dorsal lateral premotor cortex (dPMC), inferior parietal gyrus (IPG), and SMA, were more activated compared with the activation in the controls. Increased activation within the primary motor cortex (M1), dPMC, inferior frontal gyrus (IFG), and superior parietal gyrus (SPG) mainly correlated with hand movement frequency/complexity in the videos in the patients compared with controls. Conclusions The findings indicated an ongoing compensatory process occurring within the higher order motor-processing system of ALS patients, likely to overcome the loss of function. Key Points • Action observation activated similar core nodes of MNS in ALS and controls. • Increased activation within M1, dPMC, IFG and SPG mainly correlated with hand movement frequency/complexity. • Differences in patients and controls may be due to compensatory processes in ALS.
OBJECTIVE:This study was to explore the molecular mechanisms underpinning the synergetic effect between β-amyloid (Aβ) and α-synuclein (α-syn) on synapses dysfunction during the development of neurodegenerative disorders including Parkinson's disease (PD), dementia with Lewy bodies (DLB) and Alzheimer disease (AD).METHODS:The primary cultured hippocampal neurons prepared from the fetal tissue of mice were divided into six groups and treated with DMSO, Aβ(42-1), α-syn, Aβ(1-42), α-syn plus Aβ(42-1) and α-syn plus Aβ(1-42), respectively. After incubation for 24 h, the synapsin I content was calculated by immunofluorescence and the synaptic vesicle recycling was monitored by FM1-43 staining. Furthermore, the expression of cysteine string protein-α (CSPα) detected by western blot was also conducted.RESULTS:Either Aβ(1-42) or α-syn alone could induce a significant synapses dysfunction through reducing the content of synapsin I, inhibiting the synaptic vesicle recycling as well as down-regulating the expression of CSPα compared with the controls (P<0.05). However, simultaneous intervention with both α-syn and Aβ(1-42) aggravated these effects in cultured hippocampal neurons compared with the treatment with α-syn (synapsin I content: P<0.001; synaptic vesicle recycling: P=0.007; CSPα expression: P<0.001) or Aβ(1-42) (synapsin I number: P<0.001; synaptic vesicle recycling: P=0.007 CSPα expression: P<0.001) alone.CONCLUSION:There was synergistic effect between Aβ and α-syn on synapses dysfunction through reducing the synapsin I content, inhibiting the synaptic vesicle recycling and down-regulating the expression of CSPα in several neurodegenerative diseases.
BACKGROUND:TARDBP mutations have been reported in patients with amyotrophic lateral sclerosis (ALS) in different populations except Chinese. The present aim is to investigate the association between TARDBP mutations and Chinese patients with ALS.METHODS:71 SALS patients and 5 FALS families with non-SOD1 mutations were screened for TARDBP mutations via direct sequencing.RESULTS:A novel heterozygous variation, Ser292Asn (875G>A), was identified in the proband and 4 asymptomatic relatives including the children of the dead patient from a FALS family. Thus the dead patient, the proband's brother, was speculated to carry Ser292Asn though his sample was unavailable to the detection. This variation was not found in 200 unrelated control subjects. A homology search of the TDP-43 protein in different species demonstrated that it was highly conserved. Also, it was predicted to be deleterious to protein function with SIFT-calculated probabilities of 0.00. Therefore, Ser292Asn is predicted to be a pathogenic mutation. In addition, we have found two silent mutations (Gly40Gly and Ala366Ala) and one novel polymorphism (239-18t>c).CONCLUSIONS:The present data have extended the spectrum of TARDBP mutations and polymorphisms, and supported the pathological role of TDP-43 in Chinese ALS patients.
Objective To investigate the correlation between survival motor neuron (SMN) gene deletion and Chinese patients with sporadic amyotrophic lateral sclerosis (SALS).Methods A total of 141SALS patients and 134 unrelated controls were recruited from the Chinese population.Polymerase chain reaction (PCR) and restriction fragment length polymorphisro (RFLP) analysis were performed to screen SMN gene deletion.Frequencies of deletion were coropared by Chi-square test.Results Four patients and 3 controls were detected to have horoozygous SMN2 deletion.The frequencies of SMN2 deletion were 2.84%(4/141) and 2.24% (3/134), respectively, which was not significantly different (χ2= 0.0001, P =1.000).No subjects were found to have homozygous SMN1 deletion.Condusion There is no correlation between SMN gene deletion and Chinese patients with SALS.