scholarly journals Revealing the Mutational Spectrum in Southern Africans With Amyotrophic Lateral Sclerosis

2022 ◽  
Vol 8 (1) ◽  
pp. e654
Author(s):  
Melissa Nel ◽  
Amokelani C. Mahungu ◽  
Nomakhosazana Monnakgotla ◽  
Gerrit R. Botha ◽  
Nicola J. Mulder ◽  
...  

Background and ObjectivesTo perform the first screen of 44 amyotrophic lateral sclerosis (ALS) genes in a cohort of African genetic ancestry individuals with ALS using whole-genome sequencing (WGS) data.MethodsOne hundred three consecutive cases with probable/definite ALS (using the revised El Escorial criteria), and self-categorized as African genetic ancestry, underwent WGS using various Illumina platforms. As population controls, 238 samples from various African WGS data sets were included. Our analysis was restricted to 44 ALS genes, which were curated for rare sequence variants and classified according to the American College of Medical Genetics guidelines as likely benign, uncertain significance, likely pathogenic, or pathogenic variants.ResultsThirteen percent of 103 ALS cases harbored pathogenic variants; 5 different SOD1 variants (N87S, G94D, I114T, L145S, and L145F) in 5 individuals (5%, 1 familial case), pathogenic C9orf72 repeat expansions in 7 individuals (7%, 1 familial case) and a likely pathogenic ANXA11 (G38R) variant in 1 individual. Thirty individuals (29%) harbored ≥1 variant of uncertain significance; 10 of these variants had limited pathogenic evidence, although this was insufficient to permit confident classification as pathogenic.DiscussionOur findings show that known ALS genes can be expected to identify a genetic cause of disease in >11% of sporadic ALS cases of African genetic ancestry. Similar to European cohorts, the 2 most frequent genes harboring pathogenic variants in this population group are C9orf72 and SOD1.

2020 ◽  
Vol 6 (1) ◽  
pp. e390 ◽  
Author(s):  
Jennifer Roggenbuck ◽  
Marilly Palettas ◽  
Leah Vicini ◽  
Radha Patel ◽  
Adam Quick ◽  
...  

ObjectiveTo determine the incidence of amyotrophic lateral sclerosis (ALS) genetic variants in a clinic-based population.MethodsA prospective cohort of patients with definite or probable ALS was offered genetic testing using a testing algorithm based on family history and age at onset.ResultsThe incidence of pathogenic (P) or likely pathogenic (LP) variants was 56.0% in familial ALS (fALS); 11.8% in patients with ALS with a family history of dementia, and 6.8% in sporadic ALS (p < 0.001). C9orf72 expansions accounted for the majority (79%) of P or LP variants in fALS cases. Variants of uncertain significance were identified in 20.0% of fALS cases overall and in 35.7% of C9orf72-negative cases. P or LP variants were detected in 18.5% of early-onset cases (onset age <50 years); the incidence of P or LP variants was not significantly different between family history types in this group.ConclusionsOur data suggest that the incidence of P and LP variants in genes other than C9orf72 is lower than expected in Midwestern fALS cases compared with research cohorts and highlights the challenge of variant interpretation in ALS. An accurate understanding of the incidence of pathogenic variants in clinic-based ALS populations is necessary to prioritize targets for therapeutic intervention and inform clinical trial design.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
James C. Dodge ◽  
Jinlong Yu ◽  
S. Pablo Sardi ◽  
Lamya S. Shihabuddin

AbstractAberrant cholesterol homeostasis is implicated in the pathogenesis of amyotrophic lateral sclerosis (ALS), a fatal neuromuscular disease that is due to motor neuron (MN) death. Cellular toxicity from excess cholesterol is averted when it is enzymatically oxidized to oxysterols and bile acids (BAs) to promote its removal. In contrast, the auto oxidation of excess cholesterol is often detrimental to cellular survival. Although oxidized metabolites of cholesterol are altered in the blood and CSF of ALS patients, it is unknown if increased cholesterol oxidation occurs in the SC during ALS, and if exposure to oxidized cholesterol metabolites affects human MN viability. Here, we show that in the SOD1G93A mouse model of ALS that several oxysterols, BAs and auto oxidized sterols are increased in the lumbar SC, plasma, and feces during disease. Similar changes in cholesterol oxidation were found in the cervical SC of sporadic ALS patients. Notably, auto-oxidized sterols, but not oxysterols and BAs, were toxic to iPSC derived human MNs. Thus, increased cholesterol oxidation is a manifestation of ALS and non-regulated sterol oxidation likely contributes to MN death. Developing therapeutic approaches to restore cholesterol homeostasis in the SC may lead to a treatment for ALS.


2021 ◽  
Vol 49 (7) ◽  
pp. 030006052110332
Author(s):  
Zhiliang Fan ◽  
Hong Jiang ◽  
Xueqin Song ◽  
Yansu Guo ◽  
Xinying Tian

Objective To investigate whether GSTA1, GSTO2, and GSTZ1 are relevant to an increased risk of amyotrophic lateral sclerosis (ALS) in a Chinese population. Methods In this study, 143 sporadic ALS (sALS) patients (83 men, 60 women) and 210 age- and sex-matched healthy subjects were enrolled. Blood samples were collected by venipuncture. Genomic DNA was isolated by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) according to the manufacturer’s instructions. The potential associations between ALS and GSTA1, GSTO2, and GSTZ1 polymorphisms were estimated using chi-squared analysis and unconditional logistic regression. Results The D allele and genotype frequencies of GSTO2 were increased in sALS patients compared with healthy subjects, indicating that the GSTO2 DD genotype was associated with an increased risk of sALS (odds ratio [OR] = 3.294, 95% confidence interval [CI] = 1.039–10.448). However, a significant association between the DD genotype and the risk of sALS was evident in men only (OR = 7.167, 95% CI = 1.381–37.202). Conclusion This study revealed that the D allele and genotype frequencies of GSTO2 were increased in sALS patients. The GSTO2 DD genotype was associated with an increased risk of sALS in men in a Chinese population.


Biomolecules ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 437
Author(s):  
Pavlína Hemerková ◽  
Martin Vališ

Amyotrophic lateral sclerosis (ALS) affects motor neurons in the cerebral cortex, brainstem and spinal cord and leads to death due to respiratory failure within three to five years. Although the clinical symptoms of this disease were first described in 1869 and it is the most common motor neuron disease and the most common neurodegenerative disease in middle-aged individuals, the exact etiopathogenesis of ALS remains unclear and it remains incurable. However, free oxygen radicals (i.e., molecules containing one or more free electrons) are known to contribute to the pathogenesis of this disease as they very readily bind intracellular structures, leading to functional impairment. Antioxidant enzymes, which are often metalloenzymes, inactivate free oxygen radicals by converting them into a less harmful substance. One of the most important antioxidant enzymes is Cu2+Zn2+ superoxide dismutase (SOD1), which is mutated in 20% of cases of the familial form of ALS (fALS) and up to 7% of sporadic ALS (sALS) cases. In addition, the proper functioning of catalase and glutathione peroxidase (GPx) is essential for antioxidant protection. In this review article, we focus on the mechanisms through which these enzymes are involved in the antioxidant response to oxidative stress and thus the pathogenesis of ALS and their potential as therapeutic targets.


2020 ◽  
pp. 94-99
Author(s):  
P.S. Spencer ◽  

Unknown environmental factors are thought to contribute to the etiology of sporadic forms of amyotrophic lateral sclerosis (ALS). Strong evidence supporting this view is found in the post-World War decline and disappearance of highincidence ALS in three Western Pacific populations that formerly utilized neurotoxic cycad seed as a traditional source of food and/or medicine. The principal toxins in cycads (cycasin) and in False Morel mushrooms (gyromitrin) generate methyl free radicals that damage DNA and cause mutation and uncontrolled division of cycling cells and degeneration of late-/postmitotic neurons. Since False Morels are scavenged for food in Finland, Russia, Spain, and USA, research studies are underway in Western Europe and USA to determine if the practice is associated with sporadic ALS.


Neurology ◽  
2018 ◽  
Vol 90 (18) ◽  
pp. e1578-e1587 ◽  
Author(s):  
Toshio Shimizu ◽  
Kota Bokuda ◽  
Hideki Kimura ◽  
Tsutomu Kamiyama ◽  
Yuki Nakayama ◽  
...  

ObjectiveTo investigate somatosensory cortex excitability and its relationship to survival prognosis in patients with amyotrophic lateral sclerosis (ALS).MethodsA total of 145 patients with sporadic ALS and 73 healthy control participants were studied. We recorded compound muscle action potential and sensory nerve action potential of the median nerve and the median nerve somatosensory evoked potential (SEP), and we measured parameters, including onset-to-peak amplitude of N13 and N20 and peak-to-peak amplitude between N20 and P25 (N20p-P25p). Clinical prognostic factors, including ALS Functional Rating Scale–Revised, were evaluated. We followed up patients until the endpoints (death or tracheostomy) and analyzed factors associated with survival using multivariate analysis in the Cox proportional hazard model.ResultsCompared to controls, patients with ALS showed a larger amplitude of N20p-P25p in the median nerve SEP. Median survival time after examination was shorter in patients with N20p-P25p ≥8 μV (0.82 years) than in those with N20p-P25p <8 μV (1.68 years, p = 0.0002, log-rank test). Multivariate analysis identified a larger N20p-P25p amplitude as a factor that was independently associated with shorter survival (p = 0.002).ConclusionSensory cortex hyperexcitability predicts short survival in patients with ALS.


2021 ◽  
Vol 36 (6) ◽  
pp. 1205-1205
Author(s):  
Etiane Navarro ◽  
Charles J Golden

Abstract Objective Amyotrophic Lateral Sclerosis (ALS) is a progressive neurodegenerative disease caused by degeneration of the upper and lower motor neurons. This literature review examines the recurring etiology of cognitive impairments in ALS through empirical literature. The current study explores ALS across different subtypes and potential cognitive impairments. Two classifications are primarily examined ALS, and ALS with frontotemporal dementia (ALS-FTD). Involving three categories: familial inheritance pattern, genetic mutation, or sporadic. Neuropsychological studies affirm cognitive impairments in individuals diagnosed with ALS and ALS-FTD. Data Selection Data was culled from the American Psychological Association (PsycInfo), PubMed, Google Scholar. Terms used in this literature review include cognitive impairment in ALS and ALS-FTD, executive function deficiencies in ALS, neuropsychology in ALS, neuropsychological deficits in ALS, neuropsychological assessments for ALS, cognitive impairments in familial ALS, genetic ALS, and sporadic ALS, familial ALS, sporadic ALS, genetic mutations involved in ALS. Search dates December 20–23 of 2020 and March 3–4 of 2021. A total of 40 studies were examined. Data Synthesis ALS-patients demonstrate a significant cognitive impairment. However, influencing comorbidities accompanying the disease may be contributing to these impairments. Researchers employed neuroimaging and neuropsychological batteries to further understand influencing factors involved in ALS and cognition. Conclusions Researchers now understand ALS as a multi-symptomatic disorder and acknowledge the presence of cognitive impairments at various encased levels. There are limitations in neuropsychological batteries that accommodate for executive dysfunctions observed in ALS patients. Future studies should explore neuropsychological assessments that accommodate for motor deficits and dysarthria when assessing cognitive impairment in ALS patients.


2020 ◽  
Vol 10 (4) ◽  
pp. 262
Author(s):  
Giovanna Morello ◽  
Giulia Gentile ◽  
Rossella Spataro ◽  
Antonio Gianmaria Spampinato ◽  
Maria Guarnaccia ◽  
...  

Background: Repeat expansions in the spinocerebellar ataxia type 1 (SCA1) gene ATXN1 increases the risk for amyotrophic lateral sclerosis (ALS), supporting a relationship between these disorders. We recently reported the co-existence, in a large SCA1 family, of a clinically definite ALS individual bearing an intermediate ATXN1 expansion and SCA1 patients with a full expansion, some of which manifested signs of lower motor neuron involvement. Methods: In this study, we employed a systems biology approach that integrated multiple genomic analyses of the ALS patient and some SCA1 family members. Results: Our analysis identified common and distinctive candidate genes/variants and related biological processes that, in addition to or in combination with ATXN1, may contribute to motor neuron degeneration phenotype. Among these, we distinguished ALS-specific likely pathogenic variants in TAF15 and C9ORF72, two ALS-linked genes involved in the regulation of RNA metabolism, similarly to ATXN1, suggesting a selective role for this pathway in ALS pathogenesis. Conclusions: Overall, our work supports the utility to apply personal genomic information for characterizing complex disease phenotypes.


2020 ◽  
pp. jmedgenet-2020-106866 ◽  
Author(s):  
Emily P McCann ◽  
Lyndal Henden ◽  
Jennifer A Fifita ◽  
Katharine Y Zhang ◽  
Natalie Grima ◽  
...  

BackgroundAmyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with phenotypic and genetic heterogeneity. Approximately 10% of cases are familial, while remaining cases are classified as sporadic. To date, >30 genes and several hundred genetic variants have been implicated in ALS.MethodsSeven hundred and fifty-seven sporadic ALS cases were recruited from Australian neurology clinics. Detailed clinical data and whole genome sequencing (WGS) data were available from 567 and 616 cases, respectively, of which 426 cases had both datasets available. As part of a comprehensive genetic analysis, 853 genetic variants previously reported as ALS-linked mutations or disease-associated alleles were interrogated in sporadic ALS WGS data. Statistical analyses were performed to identify correlation between clinical variables, and between phenotype and the number of ALS-implicated variants carried by an individual. Relatedness between individuals carrying identical variants was assessed using identity-by-descent analysis.ResultsForty-three ALS-implicated variants from 18 genes, including C9orf72, ATXN2, TARDBP, SOD1, SQSTM1 and SETX, were identified in Australian sporadic ALS cases. One-third of cases carried at least one variant and 6.82% carried two or more variants, implicating a potential oligogenic or polygenic basis of ALS. Relatedness was detected between two sporadic ALS cases carrying a SOD1 p.I114T mutation, and among three cases carrying a SQSTM1 p.K238E mutation. Oligogenic/polygenic sporadic ALS cases showed earlier age of onset than those with no reported variant.ConclusionWe confirm phenotypic associations among ALS cases, and highlight the contribution of genetic variation to all forms of ALS.


2018 ◽  
Vol 4 (10) ◽  
pp. eaat5847 ◽  
Author(s):  
Tatsuya Osaki ◽  
Sebastien G. M. Uzel ◽  
Roger D. Kamm

Amyotrophic lateral sclerosis (ALS), a progressive neurodegenerative disease involving loss of motor neurons (MNs) and muscle atrophy, still has no effective treatment, despite much research effort. To provide a platform for testing drug candidates and investigating the pathogenesis of ALS, we developed an ALS-on-a-chip technology (i.e., an ALS motor unit) using three-dimensional skeletal muscle bundles along with induced pluripotent stem cell (iPSC)–derived and light-sensitive channelrhodopsin-2–induced MN spheroids from a patient with sporadic ALS. Each tissue was cultured in a different compartment of a microfluidic device. Axon outgrowth formed neuromuscular junctions on the muscle fiber bundles. Light was used to activate muscle contraction, which was measured on the basis of pillar deflections. Compared to a non-ALS motor unit, the ALS motor unit generated fewer muscle contractions, there was MN degradation, and apoptosis increased in the muscle. Furthermore, the muscle contractions were recovered by single treatments and cotreatment with rapamycin (a mechanistic target of rapamycin inhibitor) and bosutinib (an Src/c-Abl inhibitor). This recovery was associated with up-regulation of autophagy and degradation of TAR DNA binding protein–43 in the MNs. Moreover, administering the drugs via an endothelial cell barrier decreased the expression of P-glycoprotein (an efflux pump that transports bosutinib) in the endothelial cells, indicating that rapamycin and bosutinib cotreatment has considerable potential for ALS treatment. This ALS-on-a-chip and optogenetics technology could help to elucidate the pathogenesis of ALS and to screen for drug candidates.


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