Accumulating evidence has revealed that immunity plays an important role in amyotrophic lateral sclerosis (ALS) progression. However, the results regarding the serum levels of immunoglobulin and complement are inconsistent in patients with ALS. Although immune dysfunctions have also been reported in patients with other neurodegenerative diseases, few studies have explored whether immune dysfunction in ALS is similar to that in other neurodegenerative diseases. Therefore, we performed this study to address these gaps. In the present study, serum levels of immunoglobulin and complement were measured in 245 patients with ALS, 65 patients with multiple system atrophy (MSA), 60 patients with Parkinson's disease (PD), and 82 healthy controls (HCs). Multiple comparisons revealed that no significant differences existed between patients with ALS and other neurodegenerative diseases in immunoglobulin and complement levels. Meta-analysis based on data from our cohort and eight published articles was performed to evaluate the serum immunoglobulin and complement between patients with ALS and HCs. The pooled results showed that patients with ALS had higher C4 levels than HCs. In addition, we found that the IgG levels were lower in early-onset ALS patients than in late-onset ALS patients and HCs, and the correlations between age at onset of ALS and IgG or IgA levels were significant positive. In conclusion, our data supplement existing literature on understanding the role of peripheral immunity in ALS.
Synaptic loss is well established as the major correlate of characteristic and consistent pathology in amyotrophic lateral sclerosis (ALS). We aimed to assess the possible discriminant diagnostic value of 18 F-SynVesT-1 positron emission tomography (PET) as a marker of ALS pathology and investigate whether specific synaptic density signatures are present in ALS with different subtypes.Twenty-one patients with ALS and 25 healthy controls (HCs) were recruited. All participants underwent 18 F-SynVesT-1-PET. Synaptic density between ALS and HCs and between different ALS subgroups were compared. Correlation between synaptic density and clinical features in ALS was also analyzed.Low uptake distribution was found in the group comprising 21 ALS patients as compared with HCs in the right temporal lobe and the bilateral inferior frontal gyrus, anterior cingulate, and hippocampus-insula region. We also found low uptake in the bilateral superior temporal gyrus, hippocampus-insula, anterior cingulate, and left inferior frontal gyrus in ALS patients with cognitive impairment compared to HCs. Furthermore, compared to spinal onset ALS, bulbar onset ALS showed low uptake in the bilateral cingulate gyrus and high uptake in the bilateral superior temporal gyrus and left occipital lobe. No significant result was found in correlation analysis.This approach may provide a direct measure of synaptic density, and it therefore might represent a potentially useful biomarker for ALS diagnosis, as well as for estimating the cognitive decline and site of onset in ALS. 18 F-SynVesT-1-PET is presently not justified as a routine investigation to detect evidence of brain dysfunction leading to progression in ALS.
Abstract Introduction Recently, chloride channel CLIC‐like 1 ( CLCC1 ) was reported to be a novel ALS‐related gene. We aimed to screen CLCC1 variants in our ALS cohort and further explore the genotype–phenotype correlation of CLCC1 ‐related ALS. Methods We screened rare damaging variants in CLCC1 from our cohorts of 1005 ALS patients and 1224 healthy controls with whole‐exome sequencing in Central South China. Fisher's exact test was conducted for association analysis at the entire gene level and single variant level. Results In total, four heterozygous missense variants in CLCC1 were identified from four unrelated sporadic ALS patients and predicted to be putative pathogenic by in silico tools and protein model prediction, accounting for 0.40% of all patients (4/1005). The four variants were c.A275C (p.Q92P), c.G1139A (p.R380K), c.C1244T (p.T415M), and c.G1328A (p.R443Q), respectively, which had not been reported in ALS patients previously. Three of four variants were located in exon 10. Patients harboring CLCC1 variants seemed to share a group of similar clinical features, including earlier age at onset, rapid progression, spinal onset, and vulnerable cognitive status. Statistically, we did not find CLCC1 to be associated with the risk of ALS at the entire gene level or single variant level. Conclusion Our findings further expanded the genetic and clinical spectrum of CLCC1 ‐related ALS and provided more genetic evidence for anion channel involvement in the pathogenesis of ALS, but further investigations are needed to verify our findings.
Background: Short tandem repeats (STRs) are highly variable elements that play a pivotal role in multiple genetic diseases and the regulation of gene expression. Long-read sequencing (LRS) offers a potential solution to genome-wide STR analysis. However, characterizing STRs in human genomes using LRS on a large population scale has not been reported. Methods: We conducted the large LRS-based STR analysis in 193 unrelated samples of the Chinese population and performed genome-wide profiling of STR variation in the human genome. The repeat dynamic index (RDI) was introduced to evaluate the variability of STR. We sourced the expression data from the Genotype-Tissue Expression to explore the tissue specificity of highly variable STRs related genes across tissues. Enrichment analyses were also conducted to identify potential functional roles of the high variable STRs. Results: This study reports the large-scale analysis of human STR variation by LRS and offers a reference STR database based on the LRS dataset. We found that the disease-associated STRs (dSTRs) and STRs associated with the expression of nearby genes (eSTRs) were highly variable in the general population. Moreover, tissue-specific expression analysis showed that those highly variable STRs related genes presented the highest expression level in brain tissues, and enrichment pathways analysis found those STRs are involved in synaptic function-related pathways. Conclusion: Our study profiled the genome-wide landscape of STR using LRS and highlighted the highly variable STRs in the human genome, which provide a valuable resource for studying the role of STRs in human disease and complex traits.
To determine the frequency of spinocerebellar ataxia type 31 (SCA31) related mutations among patients from mainland China.For a cohort of molecularly unassigned patients comprised of 295 SCA patients (including 98 probands from families featuring autosomal dominant SCA and 197 sporadic cases) and 81 patients with hereditary spastic paraplegia (HSP) (including 23 probands from families with autosomal dominant HSP and 58 sporadic cases),TGGAA pentanucleotide expansion insertional mutation of the BEAN/TK2 gene was detected using repeat-primed PCR followed by capillary gel electrophoresis.No TGGAA pentanucleotide insertion expansion in BEAN/TK2 gene was identified in the above cohort.SCA31 is an extremely rare subtype of SCA and should not be included in routine genetic screening in mainland China.
Recent studies have suggested that rare variants in MFSD8 contribute to risk for frontotemporal dementia (FTD). Considering the common underlying pathogenesis and the shared genetic risk between amyotrophic lateral sclerosis (ALS) and FTD, we screened the coding region of MFSD8 in 551 unrelated patients with ALS (510 unrelated sporadic ALS and 41 familial ALS probands) from mainland China by whole-exome sequencing to assess its mutation frequency in patients with ALS and evaluate its association. Two rare deleterious variants, c.343G>A (p. V115M) and c.695T>C (p.L232P), were identified in this study. The variant c.695T>C (p.L232P) has not been previously reported and the carrier of this variant exhibits a relatively younger age of disease onset. Our studies provide some independent evidence showing that the rare variant p.L232P in MFSD8 might be a candidate risk factor for ALS. However, the relatively small sample size and the lack of patient-derived cells limit the power of the genetic exploration of this study, further robust multicenter studies with larger sizes and biological experiments with patient-derived cells are needed to elucidate the pathogenesis of the rare variant in MFSD8 in ALS.