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Tzeplaeff L, Jürs AV, Wohnrade C, Demleitner AF. Unraveling the Heterogeneity of ALS-A Call to Redefine Patient Stratification for Better Outcomes in Clinical Trials. Cells 2024; 13:452. [PMID: 38474416 PMCID: PMC10930688 DOI: 10.3390/cells13050452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 02/26/2024] [Accepted: 02/28/2024] [Indexed: 03/14/2024] Open
Abstract
Despite tremendous efforts in basic research and a growing number of clinical trials aiming to find effective treatments, amyotrophic lateral sclerosis (ALS) remains an incurable disease. One possible reason for the lack of effective causative treatment options is that ALS may not be a single disease entity but rather may represent a clinical syndrome, with diverse genetic and molecular causes, histopathological alterations, and subsequent clinical presentations contributing to its complexity and variability among individuals. Defining a way to subcluster ALS patients is becoming a central endeavor in the field. Identifying specific clusters and applying them in clinical trials could enable the development of more effective treatments. This review aims to summarize the available data on heterogeneity in ALS with regard to various aspects, e.g., clinical, genetic, and molecular.
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Affiliation(s)
- Laura Tzeplaeff
- Department of Neurology, Rechts der Isar Hospital, Technical University of Munich, 81675 München, Germany
| | - Alexandra V. Jürs
- Translational Neurodegeneration Section “Albrecht Kossel”, Department of Neurology, University Medical Center Rostock, 18057 Rostock, Germany
| | - Camilla Wohnrade
- Department of Neurology, Hannover Medical School, 30625 Hannover, Germany;
| | - Antonia F. Demleitner
- Department of Neurology, Rechts der Isar Hospital, Technical University of Munich, 81675 München, Germany
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Lin H, Chen YH. SCAF4 variants associated with focal epilepsy accompanied by multisystem disorders. Seizure 2024; 116:65-73. [PMID: 37394306 DOI: 10.1016/j.seizure.2023.06.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 06/19/2023] [Accepted: 06/21/2023] [Indexed: 07/04/2023] Open
Abstract
PURPOSE The SCAF4 gene encodes serine/arginine-related carboxyl-terminal domain-associated factor 4, which is highly expressed in the brain and potentially affects neurodevelopment. However, the functional significance of SCAF4 variants in human diseases remains unknown. METHODS Trio-based whole-exome sequencing was performed in three individuals with focal epilepsy. Bioinformatics tools were used to assess the pathogenicity of SCAF4 variants. Knockout scaf4a/b zebrafish were created using CRISPR-Cas9 used to validate the phenotype. RESULTS SCAF4 variants were identified in three individuals from three unrelated families with focal epilepsy. All patients had focal seizures and focal discharges on EEG recordings, with intellectual disability or motor retardation, skeletal abnormalities, and one had cryptorchidism. However, no recurrence was observed after short-term ASMs treatment. The identified SCAF4 variants included two nonsense variants and one compound heterozygous variant, consisting of a missense and an in-frame variant. A low frequency of SCAF4 variants was observed in gnomAD in this study. Computational modelling has suggested that missense variants lead to functional impairments. In zebrafish, abnormal epileptiform signals, skeletal development, and neurodevelopment have been found in scaf4a/b knockout compared to wild-type zebrafish. CONCLUSION These results indicate that SCAF4 is associated with focal epilepsy accompanied by multisystem disorders. Otherwise, the management of patients with SCAF4 variants requires more attention to multisystem involvement.
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Affiliation(s)
- Heng Lin
- Department of Pediatrics, Fujian Medical University Union Hospital, Fuzhou, China
| | - Yan-Hui Chen
- Department of Pediatrics, Fujian Medical University Union Hospital, Fuzhou, China.
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Lutz MW, Chiba-Falek O. Bioinformatics pipeline to guide post-GWAS studies in Alzheimer's: A new catalogue of disease candidate short structural variants. Alzheimers Dement 2023; 19:4094-4109. [PMID: 37253165 PMCID: PMC10524333 DOI: 10.1002/alz.13168] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 04/27/2023] [Accepted: 05/08/2023] [Indexed: 06/01/2023]
Abstract
BACKGROUND Short structural variants (SSVs), including insertions/deletions (indels), are common in the human genome and impact disease risk. The role of SSVs in late-onset Alzheimer's disease (LOAD) has been understudied. In this study, we developed a bioinformatics pipeline of SSVs within LOAD-genome-wide association study (GWAS) regions to prioritize regulatory SSVs based on the strength of their predicted effect on transcription factor (TF) binding sites. METHODS The pipeline utilized publicly available functional genomics data sources including candidate cis-regulatory elements (cCREs) from ENCODE and single-nucleus (sn)RNA-seq data from LOAD patient samples. RESULTS We catalogued 1581 SSVs in candidate cCREs in LOAD GWAS regions that disrupted 737 TF sites. That included SSVs that disrupted the binding of RUNX3, SPI1, and SMAD3, within the APOE-TOMM40, SPI1, and MS4A6A LOAD regions. CONCLUSIONS The pipeline developed here prioritized non-coding SSVs in cCREs and characterized their putative effects on TF binding. The approach integrates multiomics datasets for validation experiments using disease models.
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Affiliation(s)
- Michael W. Lutz
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC 27710, USA
| | - Ornit Chiba-Falek
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC 27710, USA
- Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC 27710, USA
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Theunissen F, Anderton RS, Mastaglia FL, James I, Bedlack R, Akkari PA. Intronic NEFH variant is associated with reduced risk for sporadic ALS and later age of disease onset. Sci Rep 2022; 12:14739. [PMID: 36042248 PMCID: PMC9427846 DOI: 10.1038/s41598-022-18942-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 08/22/2022] [Indexed: 11/30/2022] Open
Abstract
Neurofilament heavy (NEFH) is one of the critical proteins required for the formation of the neuronal cytoskeleton and polymorphisms in NEFH are reported as a rare cause of sporadic ALS (sALS). In the current study, a candidate tetranucleotide (TTTA) repeat variant in NEFH was selected using an in-silico short structural variant (SSV) evaluation algorithm and investigated in two cohorts of North American sALS patients, both separately and combined (Duke cohort n = 138, Coriell cohort n = 333; combined cohort n = 471), compared to a group of healthy controls from the Coriell Institute biobank (n = 496). Stratification according to site of disease onset revealed that the 9 TTTA allele was associated with reduced disease risk, specifically confined to spinal-onset sALS patients in the Duke cohort (p = 0.001). Furthermore, carriage of the 10 TTTA allele was associated with a 2.7 year later age of disease onset in the larger combined sALS cohort (p = 0.02). These results suggest that the 9 and 10 TTTA motif length may have a protective advantage for potentially lowering the risk of sALS and delaying the age of disease onset, however, these results need to be replicated in larger multicenter and multi-ethnic cohorts.
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Affiliation(s)
- Frances Theunissen
- Perron Institute for Neurological and Translational Science, First floor, RR block, QEII Medical Centre, 8 Verdun St, Nedlands, WA, 6009, Australia.,Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Perth, WA, Australia
| | - Ryan S Anderton
- Perron Institute for Neurological and Translational Science, First floor, RR block, QEII Medical Centre, 8 Verdun St, Nedlands, WA, 6009, Australia.,Centre for Neuromuscular and Neurological Disorders, University of Western Australia, Nedlands, WA, Australia.,School of Health Sciences and Institute for Health Research, University of Notre Dame Australia, Fremantle, WA, Australia
| | - Frank L Mastaglia
- Perron Institute for Neurological and Translational Science, First floor, RR block, QEII Medical Centre, 8 Verdun St, Nedlands, WA, 6009, Australia.,Centre for Neuromuscular and Neurological Disorders, University of Western Australia, Nedlands, WA, Australia
| | - Ian James
- Institute for Immunology and Infectious Diseases, Murdoch University, Perth, WA, Australia
| | | | - P Anthony Akkari
- Perron Institute for Neurological and Translational Science, First floor, RR block, QEII Medical Centre, 8 Verdun St, Nedlands, WA, 6009, Australia. .,Centre for Neuromuscular and Neurological Disorders, University of Western Australia, Nedlands, WA, Australia. .,Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Perth, WA, Australia. .,Department of Neurology, Duke University, Durham, NC, USA.
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