Most cited article - PubMed ID 38775934
Dystonia and mitochondrial disease: the movement disorder connection revisited in 900 genetically diagnosed patients
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