| 1. |
- Brenner, David, et al.
(författare)
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Hot-spot KIF5A mutations cause familial ALS
- 2018
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Ingår i: Brain. - : Oxford University Press. - 0006-8950 .- 1460-2156. ; 141, s. 688-697
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Tidskriftsartikel (refereegranskat)abstract
- Heterozygous missense mutations in the N-terminal motor or coiled-coil domains of the kinesin family member 5A (KIF5A) gene cause monogenic spastic paraplegia (HSP10) and Charcot-Marie-Tooth disease type 2 (CMT2). Moreover, heterozygous de novo frame-shift mutations in the C-terminal domain of KIF5A are associated with neonatal intractable myoclonus, a neurodevelopmental syndrome. These findings, together with the observation that many of the disease genes associated with amyotrophic lateral sclerosis disrupt cytoskeletal function and intracellular transport, led us to hypothesize that mutations in KIF5A are also a cause of amyotrophic lateral sclerosis. Using whole exome sequencing followed by rare variant analysis of 426 patients with familial amyotrophic lateral sclerosis and 6137 control subjects, we detected an enrichment of KIF5A splice-site mutations in amyotrophic lateral sclerosis (2/426 compared to 0/6137 in controls; P = 4.2 x 10-3), both located in a hot-spot in the C-terminus of the protein and predicted to affect splicing exon 27. We additionally show co-segregation with amyotrophic lateral sclerosis of two canonical splice-site mutations in two families. Investigation of lymphoblast cell lines from patients with KIF5A splice-site mutations revealed the loss of mutant RNA expression and suggested haploinsufficiency as the most probable underlying molecular mechanism. Furthermore, mRNA sequencing of a rare non-synonymous missense mutation (predicting p. Arg1007Gly) located in the C-terminus of the protein shortly upstream of the splice donor of exon 27 revealed defective KIF5A pre-mRNA splicing in respective patient-derived cell lines owing to abrogation of the donor site. Finally, the non-synonymous single nucleotide variant rs113247976 (minor allele frequency = 1.00% in controls, n = 6137), also located in the C-terminal region [p.(Pro986Leu) in exon 26], was significantly enriched in familial amyotrophic lateral sclerosis patients (minor allele frequency = 3.40%; P = 1.28 x 10-7). Our study demonstrates that mutations located specifically in a C-terminal hotspot of KIF5A can cause a classical amyotrophic lateral sclerosis phenotype, and underline the involvement of intracellular transport processes in amyotrophic lateral sclerosis pathogenesis.
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| 3. |
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| 4. |
- van Rheenen, Wouter, et al.
(författare)
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Genome-wide association analyses identify new risk variants and the genetic architecture of amyotrophic lateral sclerosis
- 2016
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 48:9, s. 1043-1048
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Tidskriftsartikel (refereegranskat)abstract
- To elucidate the genetic architecture of amyotrophic lateral sclerosis (ALS) and find associated loci, we assembled a custom imputation reference panel from whole-genome-sequenced patients with ALS and matched controls (n = 1,861). Through imputation and mixed-model association analysis in 12,577 cases and 23,475 controls, combined with 2,579 cases and 2,767 controls in an independent replication cohort, we fine-mapped a new risk locus on chromosome 21 and identified C21orf2 as a gene associated with ALS risk. In addition, we identified MOBP and SCFD1 as new associated risk loci. We established evidence of ALS being a complex genetic trait with a polygenic architecture. Furthermore, we estimated the SNP-based heritability at 8.5%, with a distinct and important role for low-frequency variants (frequency 1-10%). This study motivates the interrogation of larger samples with full genome coverage to identify rare causal variants that underpin ALS risk.
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| 5. |
- Al-Chalabi, Ammar, et al.
(författare)
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July 2017 ENCALS statement on edaravone
- 2017
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Ingår i: Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration. - : TAYLOR & FRANCIS LTD. - 2167-8421 .- 2167-9223. ; 18:7-8, s. 471-474
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Tidskriftsartikel (refereegranskat)abstract
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| 6. |
- Burkhardt, Christian, et al.
(författare)
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Is survival improved by the use of NIV and PEG in amyotrophic lateral sclerosis (ALS)? : A post-mortem study of 80 ALS patients
- 2017
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 12:5
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Tidskriftsartikel (refereegranskat)abstract
- Background: Non-invasive ventilation (NIV) and percutaneous gastrostomy (PEG) are guideline-recommended interventions for symptom management in amyotrophic lateral sclerosis (ALS). Their effect on survival is controversial and the impact on causes of death is unknown.Objective: To investigate the effect of NIV and PEG on survival and causes of death in ALS patients.Methods: Eighty deceased ALS patients underwent a complete post mortem analysis for causes of death between 2003 and 2015. Forty-two of these patients consented for genetic testing. Effects of NIV and PEG on survival and causes of death were analyzed in a multivariable Cox proportional hazard regression.Results: Six patients, who requested assisted suicide causing drug-induced hypoxia, were excluded from final analysis. Respiratory failure was the main cause of death in 72 out of 74 patients. Fifteen out of 74 died of aspiration pneumonia 23/74 of bronchopneumonia and 8/74 of a combination of aspiration pneumonia and bronchopneumonia. Twenty died of hypoxia without concomitant infection, and six patients had pulmonary embolism alone or in combination with pneumonia. NIV (p = 0.01) and PEG (p<0.01) had a significant impact on survival. In patients using NIV bronchopneumonia was significantly more frequent (p <0.04) compared to non-NIV patients. This effect was even more pronounced in limb onset patients (p<0.002). Patients with C9orf72 hexanucleotide repeat expansions showed faster disease progression and shorter survival (p = 0.01).Conclusion: The use of NIV and PEG prolongs survival in ALS. This study supports current AAN and EFNS guidelines which recommend NIV and PEG as a treatment option in ALS. The risk of bronchopneumonia as cause of death may be increased by NIV.
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| 7. |
- Czell, David, et al.
(författare)
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Further analysis of KIFAP3 gene in ALS patients from Switzerland and Sweden
- 2017
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Ingår i: Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration. - : TAYLOR & FRANCIS LTD. - 2167-8421 .- 2167-9223. ; 18:3-4, s. 302-304
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Tidskriftsartikel (refereegranskat)abstract
- A series of studies suggests that susceptibility to ALS may be influenced by variants in multiple genes. While analyses of the 10% of cases of familial origin have identified more than 33 monogenic ALS-causing genetic defects, little is known about genetic factors that influence susceptibility or phenotype in sporadic ALS (SALS). We and others conducted a genome-wide association study (GWAS) in a cohort of 1014 ALS cases from Western Europe, England and the United States, and identified an intronic single nucleotide polymorphism (SNP) rs1541160 in the KIFAP3 gene that was statistically associated with improved survival. We have now completed an additional survival analysis examining the impact of the rs1541160 genotype in a cohort of 264 ALS and progressive bulbar palsy (PBP) cases. In the combined cohort of 264 patients, the CC, CT and TT genotypes for rs1541160 were detected, respectively, in 8.3% (22), 41.7% (110) and 50.0% (132). This study does not show an influence of KIFAP3 variants on survival in the studied Swiss and Swedish cohort. There was a difference in survival between the US and English patients and the patients from the Netherlands. The effect of KIFAP3 variants may be population specific, or the rs1541160 association reported previously may have been a false-positive.
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| 8. |
- Keskin, Isil, et al.
(författare)
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Effects of Cellular Pathway Disturbances on Misfolded Superoxide Dismutase-1 in Fibroblasts Derived from ALS Patients
- 2016
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 11:2
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Tidskriftsartikel (refereegranskat)abstract
- Mutations in superoxide dismutase-1 (SOD1) are a common known cause of amyotrophic lateral sclerosis (ALS). The neurotoxicity of mutant SOD1s is most likely caused by misfolded molecular species, but disease pathogenesis is still not understood. Proposed mechanisms include impaired mitochondrial function, induction of endoplasmic reticulum stress, reduction in the activities of the proteasome and autophagy, and the formation of neurotoxic aggregates. Here we examined whether perturbations in these cellular pathways in turn influence levels of misfolded SOD1 species, potentially amplifying neurotoxicity. For the study we used fibroblasts, which express SOD1 at physiological levels under regulation of the native promoter. The cells were derived from ALS patients expressing 9 different SOD1 mutants of widely variable molecular characteristics, as well as from patients carrying the GGGGCC-repeat-expansion in C9orf72 and from non-disease controls. A specific ELISA was used to quantify soluble, misfolded SOD1, and aggregated SOD1 was analysed by western blotting. Misfolded SOD1 was detected in all lines. Levels were found to be much lower in non-disease control and the non-SOD1 C9orf72 ALS lines. This enabled us to validate patient fibroblasts for use in subsequent perturbation studies. Mitochondrial inhibition, endoplasmic reticulum stress or autophagy inhibition did not affect soluble misfolded SOD1 and in most cases, detergent-resistant SOD1 aggregates were not detected. However, proteasome inhibition led to uniformly large increases in misfolded SOD1 levels in all cell lines and an increase in SOD1 aggregation in some. Thus the ubiquitin-proteasome pathway is a principal determinant of misfolded SOD1 levels in cells derived both from patients and controls and a decline in activity with aging could be one of the factors behind the mid-to late-life onset of inherited ALS.
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| 9. |
- Nicolas, Aude, et al.
(författare)
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Genome-wide Analyses Identify KIF5A as a Novel ALS Gene
- 2018
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Ingår i: Neuron. - : Cell Press. - 0896-6273 .- 1097-4199. ; 97:6, s. 1268-1283.e6
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Tidskriftsartikel (refereegranskat)abstract
- To identify novel genes associated with ALS, we undertook two lines of investigation. We carried out a genome-wide association study comparing 20,806 ALS cases and 59,804 controls. Independently, we performed a rare variant burden analysis comparing 1,138 index familial ALS cases and 19,494 controls. Through both approaches, we identified kinesin family member 5A (KIF5A) as a novel gene associated with ALS. Interestingly, mutations predominantly in the N-terminal motor domain of KIF5A are causative for two neurodegenerative diseases: hereditary spastic paraplegia (SPG10) and Charcot-Marie-Tooth type 2 (CMT2). In contrast, ALS-associated mutations are primarily located at the C-terminal cargo-binding tail domain and patients harboring loss-of-function mutations displayed an extended survival relative to typical ALS cases. Taken together, these results broaden the phenotype spectrum resulting from mutations in KIF5A and strengthen the role of cytoskeletal defects in the pathogenesis of ALS.
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| 10. |
- Nordin, Angelica, et al.
(författare)
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Sequence variations in C9orf72 downstream of the hexanucleotide repeat region and its effect on repeat-primed PCR interpretation : a large multinational screening study
- 2017
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Ingår i: Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration. - : Informa UK Limited. - 2167-8421 .- 2167-9223. ; 18:3-4, s. 256-264
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Tidskriftsartikel (refereegranskat)abstract
- A large GGGGCC-repeat expansion mutation (HREM) in C9orf72 is the most common known cause of ALS and FTD in European populations. Sequence variations immediately downstream of the HREM region have previously been observed and have been suggested to be one reason for difficulties in interpreting RP-PCR data. Our objective was to determine the properties of these sequence variations with regard to prevalence, the range of variation, and effect on disease prognosis. We screened a multi-national cohort (n = 6981) for the HREM and samples with deviant RP-PCR curves were identified. The deviant samples were subsequently sequenced to determine sequence alteration. Our results show that in the USA and European cohorts (n = 6508) 10.7% carried the HREM and 3% had a sequence variant, while no HREM or sequence variants were observed in the Japanese cohort (n = 473). Sequence variations were more common on HREM alleles; however, certain population specific variants were associated with a non-expanded allele. In conclusion, we identified 38 different sequence variants, most located within the first 50 bp downstream of the HREM region. Furthermore, the presence of an HREM was found to be coupled to a lower age of onset and a shorter disease survival, while sequence variation did not have any correlation with these parameters.
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