Publication details
WARS2 mutations cause dopa-responsive early-onset parkinsonism and progressive myoclonus ataxia
Authors | |
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Year of publication | 2022 |
Type | Article in Periodical |
MU Faculty or unit | |
Citation | |
Web | https://www.sciencedirect.com/science/article/pii/S1353802021004375?via%3Dihub |
Doi | http://dx.doi.org/10.1016/j.parkreldis.2021.11.030 |
Keywords | WARS2; Early onset parkinsonism; Progressive myoclonus ataxia; Whole exome sequencing |
Description | Introduction: Sixteen subjects with biallelic WARS2 variants encoding the tryptophanyl mitochondrial aminoacyl-tRNA synthetase, presenting with a neonatal- or infantile-onset mitochondrial disease, have been reported to date. Here we present six novel cases with WARS2-related diseases and expand the spectrum to later onset phenotypes including dopa-responsive early-onset parkinsonism and progressive myoclonus-ataxia. Methods: Six individuals from four families underwent whole-exome sequencing within research and diagnostic settings. Following the identification of a genetic defect, in-depth phenotyping and protein expression studies were performed. Results: A relatively common (gnomAD MAF = 0.0033) pathogenic p.(Trp13Gly) missense variant in WARS2 was detected in trans in all six affected individuals in combination with different pathogenic alleles (exon 2 deletion in family 1; p.(Leu100del) in family 2; p.(Gly50Asp) in family 3; and p.(Glu208*) in family 4). Two subjects presented with action tremor around age 10-12 years and developed tremor-dominant parkinsonism with prominent neuropsychiatric features later in their 20s. Two subjects presented with a progressive myoclonusataxia dominant phenotype. One subject presented with spasticity, choreo-dystonia, myoclonus, and speech problems. One subject presented with speech problems, ataxia, and tremor. Western blotting analyses in patientderived fibroblasts showed a markedly decreased expression of the full-length WARS2 protein in both subjects carrying p.(Trp13Gly) and an exon-2 deletion in compound heterozygosity. Conclusions: This study expands the spectrum of the disease to later onset phenotypes of early-onset tremordominant parkinsonism and progressive myoclonus-ataxia phenotypes. |