Most cited article - PubMed ID 33098801
Monogenic variants in dystonia: an exome-wide sequencing study
Dystonia is a rare disease trait for which large-scale genomic investigations are still underrepresented. Genetic heterogeneity among patients with unexplained dystonia warrants interrogation of entire genome sequences, but this has not yet been systematically evaluated. To significantly enhance our understanding of the genetic contribution to dystonia, we (re)analysed 2874 whole-exome sequencing (WES), 564 whole-genome sequencing (WGS), as well as 80 fibroblast-derived proteomics datasets, representing the output of high-throughput analyses in 1990 patients and 973 unaffected relatives from 1877 families. Recruitment and precision-phenotyping procedures were driven by long-term collaborations of international experts with access to overlooked populations. By exploring WES data, we found that continuous scaling of sample sizes resulted in steady gains in the number of associated disease genes without plateauing. On average, every second diagnosis involved a gene not previously implicated in our cohort. Second-line WGS focused on a subcohort of undiagnosed individuals with high likelihood of having monogenic forms of dystonia, comprising large proportions of patients with early onset (81.3%), generalized symptom distribution (50.8%) and/or coexisting features (68.9%). We undertook extensive searches for variants in nuclear and mitochondrial genomes to uncover 38 (ultra)rare diagnostic-grade findings in 37 of 305 index patients (12.1%), many of which had remained undetected due to methodological inferiority of WES or pipeline limitations. WGS-identified elusive variations included alterations in exons poorly covered by WES, RNA-gene variants, mitochondrial-DNA mutations, small copy-number variants, complex rearranged genome structure and short tandem repeats. For improved variant interpretation in WGS-inconclusive cases, we employed systematic integration of quantitative proteomics. This aided in verifying diagnoses related to technically challenging variants and in upgrading a variant of uncertain significance (3 of 70 WGS-inconclusive index patients, 4.3%). Further, unsupervised proteomic outlier analysis supplemented with transcriptome sequencing revealed pathological gene underexpression induced by transcript disruptions in three more index patients with underlying (deep) intronic variants (3/70, 4.3%), highlighting the potential for targeted antisense-oligonucleotide therapy development. Finally, trio-WGS prioritized a de novo missense change in the candidate PRMT1, encoding a histone methyltransferase. Data-sharing strategies supported the discovery of three distinct PRMT1 de novo variants in four phenotypically similar patients, associated with loss-of-function effects in in vitro assays. This work underscores the importance of continually expanding sequencing cohorts to characterize the extensive spectrum of gene aberrations in dystonia. We show that a pool of unresolved cases is amenable to WGS and complementary multi-omic studies, directing advanced aetiopathological concepts and future diagnostic-practice workflows for dystonia.
- Keywords
- dystonia, genomics, multi-omics, proteomics, transcriptomics, whole-genome sequencing,
- MeSH
- Adult MeSH
- Dystonic Disorders * genetics MeSH
- Dystonia * genetics MeSH
- Genetic Heterogeneity MeSH
- Genomics * methods MeSH
- Middle Aged MeSH
- Humans MeSH
- Proteomics * methods MeSH
- Whole Genome Sequencing MeSH
- Exome Sequencing MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
BACKGROUND: Defects of mitochondrial ATP synthase (ATPase) represent an emerging, yet incompletely understood group of neurodevelopmental diseases with abnormal movements. OBJECTIVE: The aim of this study was to redefine the phenotypic and mutational spectrum of movement disorders linked to the ATPase subunit-encoding genes ATP5F1A and ATP5F1B. METHODS: We recruited regionally distant patients who had been genome or exome sequenced. Fibroblast cultures from two patients were established to perform RNA sequencing, immunoblotting, mass spectrometry-based high-throughput quantitative proteomics, and ATPase activity assays. In silico three-dimensional missense variant modeling was performed. RESULTS: We identified a patient with developmental delay, myoclonic dystonia, and spasticity who carried a heterozygous frameshift c.1404del (p.Glu469Serfs*3) variant in ATP5F1A. The patient's cells exhibited significant reductions in ATP5F1A mRNA, underexpression of the α-subunit of ATPase in association with other aberrantly expressed ATPase components, and compromised ATPase activity. In addition, a novel deleterious heterozygous ATP5F1A missense c.1252G>A (p.Gly418Arg) variant was discovered, shared by three patients from two families with hereditary spastic paraplegia (HSP). This variant mapped to a functionally important intersubunit communication site. A third heterozygous variant, c.1074+1G>T, affected a canonical donor splice site of ATP5F1B and resulted in exon skipping with significantly diminished ATP5F1B mRNA levels, as well as impaired ATPase activity. The associated phenotype consisted of cerebral palsy (CP) with prominent generalized dystonia. CONCLUSIONS: Our data confirm and expand the role of dominant ATP5F1A and ATP5F1B variants in neurodevelopmental movement disorders. ATP5F1A/ATP5F1B-related ATPase diseases should be considered as a cause of dystonia, HSP, and CP. © 2025 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
- Keywords
- ATP synthase, ATP5F1A, ATP5F1B, cerebral palsy, dominant variant, dystonia, mitochondrial disease, spasticity,
- MeSH
- Alleles MeSH
- Child MeSH
- Phenotype MeSH
- Humans MeSH
- Mitochondrial Proton-Translocating ATPases * genetics MeSH
- Mutation genetics MeSH
- Movement Disorders * genetics MeSH
- Check Tag
- Child MeSH
- Humans MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Case Reports MeSH
- Names of Substances
- ATP5F1A protein, human MeSH Browser
- ATP5F1B protein, human MeSH Browser
- Mitochondrial Proton-Translocating ATPases * MeSH
BACKGROUND: Despite considerable heritability, previous smaller genome-wide association studies (GWASs) have not identified any robust genetic risk factors for isolated dystonia. OBJECTIVE: The objective of this study was to perform a large-scale GWAS in a well-characterized, multicenter sample of >6000 individuals to identify genetic risk factors for isolated dystonia. METHODS: Array-based GWASs were performed on autosomes for 4303 dystonia participants and 2362 healthy control subjects of European ancestry with subgroup analysis based on age at onset, affected body regions, and a newly developed clinical score. Another 736 individuals were used for validation. RESULTS: This GWAS identified no common genome-wide significant loci that could be replicated despite sufficient power to detect meaningful effects. Power analyses imply that the effects of individual variants are likely very small. CONCLUSIONS: Moderate single-nucleotide polymorphism-based heritability indicates that common variants do not contribute to isolated dystonia in this cohort. Sequence-based GWASs (eg, by whole-genome sequencing) might help to better understand the genetic basis. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
- Keywords
- GWAS, age at onset, case–control, clinical score, isolated dystonia,
- MeSH
- Genome-Wide Association Study * MeSH
- Adult MeSH
- Dystonic Disorders genetics MeSH
- Dystonia * genetics MeSH
- Genetic Predisposition to Disease * genetics MeSH
- Polymorphism, Single Nucleotide * genetics MeSH
- Middle Aged MeSH
- Humans MeSH
- Risk Factors MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Multicenter Study MeSH
- MeSH
- Adult MeSH
- Dystonia * genetics diagnosis MeSH
- Middle Aged MeSH
- Humans MeSH
- Mitochondrial Diseases * genetics diagnosis MeSH
- Adolescent MeSH
- Mutation MeSH
- Movement Disorders genetics diagnosis physiopathology MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Adolescent MeSH
- Male MeSH
- Female MeSH
- Publication type
- Letter MeSH
BACKGROUND: DYT6 dystonia belongs to a group of isolated, genetically determined, generalized dystonia associated with mutations in the THAP1 gene. CASE PRESENTATION: We present the case of a young patient with DYT6 dystonia associated with a newly discovered c14G>A (p.Cys5Tyr) mutation in the THAP1 gene. We describe the clinical phenotype of this new mutation, effect of pallidal deep brain stimulation (DBS), which was accompanied by two rare postimplantation complications: an early intracerebral hemorrhage and delayed epileptic seizures. Among the published case reports of patients with DYT6 dystonia, the mentioned complications have not been described so far. CONCLUSIONS: DBS in the case of DYT6 dystonia is a challenge to thoroughly consider possible therapeutic benefits and potential risks associated with surgery. Genetic heterogeneity of the disease may also play an important role in predicting the development of the clinical phenotype as well as the effect of treatment including DBS. Therefore, it is beneficial to analyze the genetic and clinical relationships of DYT6 dystonia.
- Keywords
- DYT6, Deep brain stimulation, Dystonia, Hemorrhage, Seizures,
- MeSH
- DNA-Binding Proteins genetics MeSH
- Dystonic Disorders * genetics therapy MeSH
- Dystonia * genetics therapy MeSH
- Deep Brain Stimulation * adverse effects MeSH
- Nuclear Proteins genetics MeSH
- Humans MeSH
- Apoptosis Regulatory Proteins genetics MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Case Reports MeSH
- Names of Substances
- DNA-Binding Proteins MeSH
- Nuclear Proteins MeSH
- Apoptosis Regulatory Proteins MeSH
- THAP1 protein, human MeSH Browser
An association between movement disorders and immune-system dysfunction has been described in the context of rare genetic diseases such as ataxia telangiectasia as well as infectious encephalopathies. We encountered a male patient who presented immunodeficiency of unknown etiology since childhood. A medication-refractory, progressive choreodystonic movement disorder emerged at the age of 42 years and prompted an exome-wide molecular testing approach. This revealed a pathogenic hemizygous variant in CD40LG, the gene implicated in X-linked hyper-IgM syndrome. Only two prior reports have specifically suggested a causal relationship between CD40LG mutations and involuntary hyperkinetic movements. Our findings thus confirm the existence of a particular CD40LG-related condition, combining features of compromised immunity with neurodegenerative movement abnormalities. Establishing the diagnosis is crucial because of potential life-threatening immunological complications.
- MeSH
- Child MeSH
- Adult MeSH
- Hyper-IgM Immunodeficiency Syndrome, Type 1 * genetics pathology MeSH
- Humans MeSH
- CD40 Ligand genetics MeSH
- Mutation MeSH
- Check Tag
- Child MeSH
- Adult MeSH
- Humans MeSH
- Male MeSH
- Publication type
- Journal Article MeSH
- Case Reports MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- CD40 Ligand MeSH
OBJECTIVE: ATP synthase (ATPase) is responsible for the majority of ATP production. Nevertheless, disease phenotypes associated with mutations in ATPase subunits are extremely rare. We aimed at expanding the spectrum of ATPase-related diseases. METHODS: Whole-exome sequencing in cohorts with 2,962 patients diagnosed with mitochondrial disease and/or dystonia and international collaboration were used to identify deleterious variants in ATPase-encoding genes. Findings were complemented by transcriptional and proteomic profiling of patient fibroblasts. ATPase integrity and activity were assayed using cells and tissues from 5 patients. RESULTS: We present 10 total individuals with biallelic or de novo monoallelic variants in nuclear ATPase subunit genes. Three unrelated patients showed the same homozygous missense ATP5F1E mutation (including one published case). An intronic splice-disrupting alteration in compound heterozygosity with a nonsense variant in ATP5PO was found in one patient. Three patients had de novo heterozygous missense variants in ATP5F1A, whereas another 3 were heterozygous for ATP5MC3 de novo missense changes. Bioinformatics methods and populational data supported the variants' pathogenicity. Immunohistochemistry, proteomics, and/or immunoblotting revealed significantly reduced ATPase amounts in association to ATP5F1E and ATP5PO mutations. Diminished activity and/or defective assembly of ATPase was demonstrated by enzymatic assays and/or immunoblotting in patient samples bearing ATP5F1A-p.Arg207His, ATP5MC3-p.Gly79Val, and ATP5MC3-p.Asn106Lys. The associated clinical profiles were heterogeneous, ranging from hypotonia with spontaneous resolution (1/10) to epilepsy with early death (1/10) or variable persistent abnormalities, including movement disorders, developmental delay, intellectual disability, hyperlactatemia, and other neurologic and systemic features. Although potentially reflecting an ascertainment bias, dystonia was common (7/10). INTERPRETATION: Our results establish evidence for a previously unrecognized role of ATPase nuclear-gene defects in phenotypes characterized by neurodevelopmental and neurodegenerative features. ANN NEUROL 2022;91:225-237.
- MeSH
- Dystonia enzymology genetics MeSH
- Epilepsy genetics MeSH
- Phenotype MeSH
- Genetic Variation MeSH
- Humans MeSH
- Mutation, Missense MeSH
- Mitochondrial ADP, ATP Translocases genetics MeSH
- Mitochondrial Diseases enzymology genetics MeSH
- Mitochondrial Proton-Translocating ATPases genetics MeSH
- Mitochondria enzymology genetics MeSH
- Models, Molecular MeSH
- Mutation MeSH
- Nervous System Diseases enzymology genetics MeSH
- Neurodegenerative Diseases enzymology genetics MeSH
- Neurodevelopmental Disorders enzymology genetics MeSH
- Proteomics MeSH
- Pedigree MeSH
- Exome Sequencing MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Research Support, N.I.H., Extramural MeSH
- Names of Substances
- ATP5F1A protein, human MeSH Browser
- ATP5PD protein, human MeSH Browser
- Mitochondrial ADP, ATP Translocases MeSH
- Mitochondrial Proton-Translocating ATPases MeSH
SPTBN1 encodes βII-spectrin, the ubiquitously expressed β-spectrin that forms micrometer-scale networks associated with plasma membranes. Mice deficient in neuronal βII-spectrin have defects in cortical organization, developmental delay and behavioral deficiencies. These phenotypes, while less severe, are observed in haploinsufficient animals, suggesting that individuals carrying heterozygous SPTBN1 variants may also show measurable compromise of neural development and function. Here we identify heterozygous SPTBN1 variants in 29 individuals with developmental, language and motor delays; mild to severe intellectual disability; autistic features; seizures; behavioral and movement abnormalities; hypotonia; and variable dysmorphic facial features. We show that these SPTBN1 variants lead to effects that affect βII-spectrin stability, disrupt binding to key molecular partners, and disturb cytoskeleton organization and dynamics. Our studies define SPTBN1 variants as the genetic basis of a neurodevelopmental syndrome, expand the set of spectrinopathies affecting the brain and underscore the critical role of βII-spectrin in the central nervous system.
- MeSH
- Genes, Dominant * MeSH
- Phenotype MeSH
- Genetic Predisposition to Disease * MeSH
- Genetic Variation * MeSH
- Genetic Association Studies methods MeSH
- Heterozygote MeSH
- Humans MeSH
- Mice MeSH
- Neurodevelopmental Disorders diagnosis genetics MeSH
- Spectrin genetics metabolism MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Research Support, N.I.H., Extramural MeSH
- Names of Substances
- Spectrin MeSH
- SPTBN1 protein, human MeSH Browser
Improved care for people with dystonia presents a number of challenges. Major gaps in knowledge exist with regard to how to optimize the diagnostic process, how to leverage discoveries in pathophysiology into biomarkers, and how to develop an evidence base for current and novel treatments. These challenges are made greater by the realization of the wide spectrum of symptoms and difficulties faced by people with dystonia, which go well-beyond motor symptoms. A network of clinicians, scientists, and patients could provide resources to facilitate information exchange at different levels, share mutual experiences, and support each other's innovative projects. In the past, collaborative initiatives have been launched, including the American Dystonia Coalition, the European Cooperation in Science and Technology (COST-which however only existed for a limited time), and the Dutch DystonieNet project. The European Reference Network on Rare Neurological Diseases includes dystonia among other rare conditions affecting the central nervous system in a dedicated stream. Currently, we aim to broaden the scope of these initiatives to a comprehensive European level by further expanding the DystoniaNet network, in close collaboration with the ERN-RND. In line with the ERN-RND, the mission of DystoniaNet Europe is to improve care and quality of life for people with dystonia by, among other endeavors, facilitating access to specialized care, overcoming the disparity in education of medical professionals, and serving as a solid platform to foster international clinical and research collaborations. In this review, both professionals within the dystonia field and patients and caregivers representing Dystonia Europe highlight important unsolved issues and promising new strategies and the role that a European network can play in activating them.
- Keywords
- DystoniaNet, European network, collaboration, dystonia, unmet needs,
- Publication type
- Journal Article MeSH
- Review MeSH