| 1. |
- Kenna, Kevin P., et al.
(författare)
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NEK1 variants confer susceptibility to 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. 1037-1042
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Tidskriftsartikel (refereegranskat)abstract
- To identify genetic factors contributing to amyotrophic lateral sclerosis (ALS), we conducted whole-exome analyses of 1,022 index familial ALS (FALS) cases and 7,315 controls. In a new screening strategy, we performed gene-burden analyses trained with established ALS genes and identified a significant association between loss-of-function (LOF) NEK1 variants and FALS risk. Independently, autozygosity mapping for an isolated community in the Netherlands identified a NEK1 p.Arg261 His variant as a candidate risk factor. Replication analyses of sporadic ALS (SALS) cases and independent control cohorts confirmed significant disease association for both p.Arg261 His (10,589 samples analyzed) and NEK1 LOF variants (3,362 samples analyzed). In total, we observed NEK1 risk variants in nearly 3% of ALS cases. NEK1 has been linked to several cellular functions, including cilia formation, DNA-damage response, microtubule stability, neuronal morphology and axonal polarity. Our results provide new and important insights into ALS etiopathogenesis and genetic etiology.
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| 2. |
- Diekstra, Frank P., et al.
(författare)
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C9orf72 and UNC13A Are Shared Risk Loci for Amyotrophic Lateral Sclerosis and Frontotemporal Dementia : A Genome-Wide Meta-Analysis
- 2014
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Ingår i: Annals of Neurology. - : John Wiley & Sons. - 0364-5134 .- 1531-8249. ; 76:1, s. 120-133
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Substantial clinical, pathological, and genetic overlap exists between amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). TDP-43 inclusions have been found in both ALS and FTD cases (FTD-TDP). Recently, a repeat expansion in C9orf72 was identified as the causal variant in a proportion of ALS and FTD cases. We sought to identify additional evidence for a common genetic basis for the spectrum of ALS-FTD. Methods: We used published genome-wide association studies data for 4,377 ALS patients and 13,017 controls, and 435 pathology-proven FTD-TDP cases and 1,414 controls for genotype imputation. Data were analyzed in a joint meta-analysis, by replicating topmost associated hits of one disease in the other, and by using a conservative rank products analysis, allocating equal weight to ALS and FTD-TDP sample sizes. Results: Meta-analysis identified 19 genome-wide significant single nucleotide polymorphisms (SNPs) in C9orf72 on chromosome 9p21.2 (lowest p = 2.6 x 10(-12)) and 1 SNP in UNC13A on chromosome 19p13.11 (p = 1.0 x 10(-11)) as shared susceptibility loci for ALS and FTD-TDP. Conditioning on the 9p21.2 genotype increased statistical significance at UNC13A. A third signal, on chromosome 8q24.13 at the SPG8 locus coding for strumpellin (p = 3.91 x 10(-7)) was replicated in an independent cohort of 4,056 ALS patients and 3,958 controls (p = 0.026; combined analysis p = 1.01 x 10(-7)). Interpretation: We identified common genetic variants in C9orf72, but in addition in UNC13A that are shared between ALS and FTD. UNC13A provides a novel link between ALS and FTD-TDP, and identifies changes in neurotransmitter release and synaptic function as a converging mechanism in the pathogenesis of ALS and FTD-TDP.
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| 3. |
- Diekstra, Frank P., et al.
(författare)
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Mapping of Gene Expression Reveals CYP27A1 as a Susceptibility Gene for Sporadic ALS
- 2012
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:4, s. e35333-
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Tidskriftsartikel (refereegranskat)abstract
- Amyotrophic lateral sclerosis (ALS) is a progressive, neurodegenerative disease characterized by loss of upper and lower motor neurons. ALS is considered to be a complex trait and genome-wide association studies (GWAS) have implicated a few susceptibility loci. However, many more causal loci remain to be discovered. Since it has been shown that genetic variants associated with complex traits are more likely to be eQTLs than frequency-matched variants from GWAS platforms, we conducted a two-stage genome-wide screening for eQTLs associated with ALS. In addition, we applied an eQTL analysis to finemap association loci. Expression profiles using peripheral blood of 323 sporadic ALS patients and 413 controls were mapped to genome-wide genotyping data. Subsequently, data from a two-stage GWAS (3,568 patients and 10,163 controls) were used to prioritize eQTLs identified in the first stage (162 ALS, 207 controls). These prioritized eQTLs were carried forward to the second sample with both gene-expression and genotyping data (161 ALS, 206 controls). Replicated eQTL SNPs were then tested for association in the second-stage GWAS data to find SNPs associated with disease, that survived correction for multiple testing. We thus identified twelve cis eQTLs with nominally significant associations in the second-stage GWAS data. Eight SNP-transcript pairs of highest significance (lowest p = 1.27 x 10(-51)) withstood multiple-testing correction in the second stage and modulated CYP27A1 gene expression. Additionally, we show that C9orf72 appears to be the only gene in the 9p21.2 locus that is regulated in cis, showing the potential of this approach in identifying causative genes in association loci in ALS. This study has identified candidate genes for sporadic ALS, most notably CYP27A1. Mutations in CYP27A1 are causal to cerebrotendinous xanthomatosis which can present as a clinical mimic of ALS with progressive upper motor neuron loss, making it a plausible susceptibility gene for ALS.
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