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| 2. |
- van Rheenen, W, et al.
(author)
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Common and rare variant association analyses in amyotrophic lateral sclerosis identify 15 risk loci with distinct genetic architectures and neuron-specific biology
- 2021
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In: Nature genetics. - : Springer Science and Business Media LLC. - 1546-1718 .- 1061-4036. ; 53:12, s. 1636-
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Journal article (peer-reviewed)abstract
- Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with a lifetime risk of one in 350 people and an unmet need for disease-modifying therapies. We conducted a cross-ancestry genome-wide association study (GWAS) including 29,612 patients with ALS and 122,656 controls, which identified 15 risk loci. When combined with 8,953 individuals with whole-genome sequencing (6,538 patients, 2,415 controls) and a large cortex-derived expression quantitative trait locus (eQTL) dataset (MetaBrain), analyses revealed locus-specific genetic architectures in which we prioritized genes either through rare variants, short tandem repeats or regulatory effects. ALS-associated risk loci were shared with multiple traits within the neurodegenerative spectrum but with distinct enrichment patterns across brain regions and cell types. Of the environmental and lifestyle risk factors obtained from the literature, Mendelian randomization analyses indicated a causal role for high cholesterol levels. The combination of all ALS-associated signals reveals a role for perturbations in vesicle-mediated transport and autophagy and provides evidence for cell-autonomous disease initiation in glutamatergic neurons.
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| 3. |
- Lahrouchi, Najim, et al.
(author)
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Transethnic Genome-Wide Association Study Provides Insights in the Genetic Architecture and Heritability of Long QT Syndrome
- 2020
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In: Circulation. - : Lippincott Williams & Wilkins. - 0009-7322 .- 1524-4539. ; 142:4, s. 324-338
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Journal article (peer-reviewed)abstract
- Background: Long QT syndrome (LQTS) is a rare genetic disorder and a major preventable cause of sudden cardiac death in the young. A causal rare genetic variant with large effect size is identified in up to 80% of probands (genotype positive) and cascade family screening shows incomplete penetrance of genetic variants. Furthermore, a proportion of cases meeting diagnostic criteria for LQTS remain genetically elusive despite genetic testing of established genes (genotype negative). These observations raise the possibility that common genetic variants with small effect size contribute to the clinical picture of LQTS. This study aimed to characterize and quantify the contribution of common genetic variation to LQTS disease susceptibility. Methods: We conducted genome-wide association studies followed by transethnic meta-analysis in 1656 unrelated patients with LQTS of European or Japanese ancestry and 9890 controls to identify susceptibility single nucleotide polymorphisms. We estimated the common variant heritability of LQTS and tested the genetic correlation between LQTS susceptibility and other cardiac traits. Furthermore, we tested the aggregate effect of the 68 single nucleotide polymorphisms previously associated with the QT-interval in the general population using a polygenic risk score. Results: Genome-wide association analysis identified 3 loci associated with LQTS at genome-wide statistical significance (P<5x10(-8)) nearNOS1AP,KCNQ1, andKLF12, and 1 missense variant inKCNE1(p.Asp85Asn) at the suggestive threshold (P<10(-6)). Heritability analyses showed that approximate to 15% of variance in overall LQTS susceptibility was attributable to common genetic variation (h2SNP0.148; standard error 0.019). LQTS susceptibility showed a strong genome-wide genetic correlation with the QT-interval in the general population (r(g)=0.40;P=3.2x10(-3)). The polygenic risk score comprising common variants previously associated with the QT-interval in the general population was greater in LQTS cases compared with controls (P<10-13), and it is notable that, among patients with LQTS, this polygenic risk score was greater in patients who were genotype negative compared with those who were genotype positive (P<0.005). Conclusions: This work establishes an important role for common genetic variation in susceptibility to LQTS. We demonstrate overlap between genetic control of the QT-interval in the general population and genetic factors contributing to LQTS susceptibility. Using polygenic risk score analyses aggregating common genetic variants that modulate the QT-interval in the general population, we provide evidence for a polygenic architecture in genotype negative LQTS.
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| 4. |
- Freischmidt, Axel, et al.
(author)
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A serum microRNA sequence reveals fragile X protein pathology in amyotrophic lateral sclerosis
- 2021
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In: Brain. - : Oxford University Press. - 0006-8950 .- 1460-2156. ; 144:4, s. 1214-1229
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Journal article (peer-reviewed)abstract
- Knowledge about converging disease mechanisms in the heterogeneous syndrome amyotrophic lateral sclerosis (ALS) is rare, but may lead to therapies effective in most ALS cases. Previously, we identified serum microRNAs downregulated in familial ALS, the majority of sporadic ALS patients, but also in presymptomatic mutation carriers. A 5-nucleotide sequence motif (GDCGG; D = G, A or U) was strongly enriched in these ALS-related microRNAs. We hypothesized that deregulation of protein(s) binding predominantly to this consensus motif was responsible for the ALS-linked microRNA fingerprint. Using microRNA pull-down assays combined with mass spectrometry followed by extensive biochemical validation, all members of the fragile X protein family, FMR1, FXR1 and FXR2, were identified to directly and predominantly interact with GDCGG microRNAs through their structurally disordered RGG/RG domains. Preferential association of this protein family with ALS-related microRNAs was confirmed by in vitro binding studies on a transcriptome-wide scale. Immunohistochemistry of lumbar spinal cord revealed aberrant expression level and aggregation of FXR1 and FXR2 in C9orf72- and FUS-linked familial ALS, but also patients with sporadic ALS. Further analysis of ALS autopsies and induced pluripotent stem cell-derived motor neurons with FUS mutations showed co-aggregation of FXR1 with FUS. Hence, our translational approach was able to take advantage of blood microRNAs to reveal CNS pathology, and suggests an involvement of the fragile X-related proteins in familial and sporadic ALS already at a presymptomatic stage. The findings may uncover disease mechanisms relevant to many patients with ALS. They furthermore underscore the systemic, extra-CNS aspect of ALS.
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| 5. |
- Kuraszkiewicz, B., et al.
(author)
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Potential Preventive Strategies for Amyotrophic Lateral Sclerosis
- 2020
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In: Frontiers in Neuroscience. - : Frontiers Media S.A.. - 1662-4548 .- 1662-453X. ; 14
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Research review (peer-reviewed)abstract
- It may seem useless to propose preventive measures for a disease without established pathogenesis and successful therapy, such as amyotrophic lateral sclerosis (ALS). However, we will show that ALS shares essential molecular mechanisms with aging and that established anti-aging strategies, such as healthy diet or individually adjusted exercise, may be successfully applied to ameliorate the condition of ALS patients. These strategies might be applied for prevention if persons at ALS risk could be identified early enough. Recent research advances indicate that this may happen soon.
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| 6. |
- Pröbstel, Anne-Katrin, et al.
(author)
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Gut microbiota-specific IgA+ B cells traffic to the CNS in active multiple sclerosis
- 2020
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In: Science immunology. - : American Association for the Advancement of Science. - 2470-9468. ; 5:53
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Journal article (peer-reviewed)abstract
- Changes in gut microbiota composition and a diverse role of B cells have recently been implicated in multiple sclerosis (MS), a central nervous system (CNS) autoimmune disease. Immunoglobulin A (IgA) is a key regulator at the mucosal interface. However, whether gut microbiota shape IgA responses and what role IgA+ cells have in neuroinflammation are unknown. Here, we identify IgA-bound taxa in MS and show that IgA-producing cells specific for MS-associated taxa traffic to the inflamed CNS, resulting in a strong, compartmentalized IgA enrichment in active MS and other neuroinflammatory diseases. Unlike previously characterized polyreactive anti-commensal IgA responses, CNS IgA cross-reacts with surface structures on specific bacterial strains but not with brain tissue. These findings establish gut microbiota-specific IgA+ cells as a systemic mediator in MS and suggest a critical role of mucosal B cells during active neuroinflammation with broad implications for IgA as an informative biomarker and IgA-producing cells as an immune subset to harness for therapeutic interventions.
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| 7. |
- Yilmaz, Rüstem, et al.
(author)
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SQSTM1/p62 variants in 486 patients with familial ALS from Germany and Sweden
- 2020
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In: Neurobiology of Aging. - : ELSEVIER SCIENCE INC. - 0197-4580 .- 1558-1497. ; 87, s. 139.e9-139.e15
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Journal article (peer-reviewed)abstract
- Several studies reported amyotrophic lateral sclerosis (ALS)-linked mutations in TBK1, OPTN, VCP, UBQLN2, and SQSTM1 genes encoding proteins involved in autophagy. SQSTM1 was originally identified by a candidate gene approach because it encodes p62, a multifunctional protein involved in protein degradation both through proteasomal regulation and autophagy. Both p62 and optineurin (encoded by OPTN) are direct interaction partners and substrates of TBK1, and these 3 proteins form the core of a genetic and functional network that may connect autophagy with ALS. Considering the molecular and conceptual relevance of the TBK1/OPTN/SQSTM1 "triangle," we here performed a targeted screen for SQSTM1 variants in 486 patients with familial ALS from Germany and Sweden by analyzing whole-exome sequencing data. We report 9 novel and 5 previously reported rare variants in SQSTM1 and discuss the current evidence for SQSTM1 as a primary disease gene for ALS. We conclude that the evidence for causality remains vague for SQSTM1 and is weaker than for the other autophagy genes, for example, TBK1 and OPTN.
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| 9. |
- Kuzma-Kozakiewicz, Magdalena, et al.
(author)
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Putative founder effect in the Polish, Iranian and United States populations for the L144SSOD1mutation associated with slowly uniform phenotype of amyotrophic lateral sclerosis
- 2021
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In: Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration. - : Taylor & Francis. - 2167-8421 .- 2167-9223. ; 22:1-2, s. 80-85
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Journal article (peer-reviewed)abstract
- Mutations inSOD1cause approximately 12-25% of familial ALS and approximate to 2% of apparently sporadic ALS cases. Clinical phenotypes linked to SOD1 mutations are heterogeneous and intra-familial variability of the clinical phenotype is frequently observed. SOD1 L144S mutation, identified also in Brazil, Iran and United States, is the second most frequent mutation among ALS patients in Poland. So far, 10 FALS pedigrees with SOD1 L144S mutation have been reported worldwide. The aim of the study was to establish the origin of SOD1 L144S mutation in geographically distinct populations. The clinical presentation of the Polish patients was compared with those from the previously reported populations (26 ever-reported patients). Clinically, L144S mutation is associated with both sporadic and familial ALS of relatively slow uniform course, a prevalent onset in the lower limbs, either classic or PMA presentation and a long survival time. Like in the case of other previously described SOD1 mutations, there was an intra-familial heterogeneity and reduced penetrance for ALS was observed. We propose that the L144S SOD1 mutation in the three studied populations has a common founder most likely of Polish origin.
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| 10. |
- Lulé, Dorothée E., et al.
(author)
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Deficits in verbal fluency in presymptomatic C9orf72 mutation gene carriers-a developmental disorder
- 2020
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In: Journal of Neurology, Neurosurgery and Psychiatry. - : BMJ Publishing Group Ltd. - 0022-3050 .- 1468-330X. ; 91:11, s. 1195-1200
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Journal article (peer-reviewed)abstract
- Background: A mutation in C9orf72 constitute a cross-link between amyotrophic lateral sclerosis (ALS) and fronto-temporal dementia (FTD). At clinical manifestation, both patient groups may present with either cognitive impairment of predominantly behaviour or language (in FTD) or motor dysfunctions (in ALS).Methods: In total, 36 non-symptomatic mutation carriers from ALS or FTD families were examined, including 21 subjects with C9orf72 and 15 with SOD1 mutations. Data were compared with 91 age-matched, education-matched and gender-matched healthy subjects (56 were first-degree relatives from ALS or FTD families, 35 with no known family history of ALS/FTD). MRI scanning for diffusion tensor imaging was performed to map fractional anisotropy (FA). Subjects performed an extensive neuropsychological assessment to address verbal fluency, language, executive, memory and visuospatial function. Measurements were repeated after 12 months.Results: C9orf72 expansion carriers performed significantly worse in verbal fluency and non-verbal memory and presented with distinct alterations in structural white matter integrity indicated by lower FA values in inferior and orbitofrontal cortical areas compared with carriers of SOD1 mutations or healthy subjects. Loss of structural integrity was associated with decreased verbal fluency performance. White matter alterations and cognitive performance showed no changes over 12 months in all subjects.Discussion: Reduced verbal fluency performance seems to be a distinct clinical feature of C9orf72 carriers before symptomatic disease onset without evidence for change over time in our cohort. The results support the emerging hypothesis of a general disorder in development in addition to neurodegeneration in C9orf72 carriers.
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