| 1. |
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| 2. |
- Andreasson, M., et al.
(författare)
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Altered CSF levels of monoamines in hereditary spastic paraparesis 10 A case series
- 2019
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Ingår i: Neurology-Genetics. - : Ovid Technologies (Wolters Kluwer Health). - 2376-7839. ; 5:4
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Tidskriftsartikel (refereegranskat)abstract
- Objective To perform a comprehensive clinical characterization and biochemical CSF profile analyses in 2 Swedish families with hereditary spastic paraparesis (HSP) 10 (SPG10) caused by 2 different mutations in the neuronal kinesin heavy chain gene (KIF5A). Methods Structured clinical assessment, genetic studies, and neuroradiologic and electrophysiological evaluations were performed in 4 patients from 2 families with SPG10. Additional CSF analysis was conducted in 3 patients with regard to levels of neurodegenerative markers and monoamine metabolism. Results All patients exhibited a complex form of HSP with a mild to moderate concurrent axonal polyneuropathy. The heterozygous missense mutations c.767A>G and c.967C>T in KIF5A were found. Wide intrafamilial phenotype variability was evident in both families. CSF analysis demonstrated a mild elevation of neurofilament light (NFL) chain in the patient with longest disease duration. Unexpectedly, all patients exhibited increased levels of the dopamine metabolite, homovanillic acid, whereas decreased levels of the noradrenergic metabolite, 3-methoxy-4-hydroxyphenylglycol, were found in 2 of 3 patients. Conclusions We report on CSF abnormalities in SPG10, demonstrating that NFL elevation is not a mandatory finding but may appear after long-standing disease. Impaired transportation of synaptic proteins may be a possible explanation for the increased dopaminergic turnover and noradrenergic deficiency identified. The reasons for these selective abnormalities, unrelated to obvious clinical features, remain to be explained. Our findings need further confirmation in larger cohorts of patients harboring KIF5A mutations.
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| 8. |
- Giese, A. K., et al.
(författare)
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Design and rationale for examining neuroimaging genetics in ischemic stroke The MRI-GENIE study
- 2017
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Ingår i: Neurology-Genetics. - : Ovid Technologies (Wolters Kluwer Health). - 2376-7839. ; 3:5
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To describe the design and rationale for the genetic analysis of acute and chronic cerebrovascular neuroimaging phenotypes detected on clinical MRI in patients with acute ischemic stroke (AIS) within the scope of the MRI-GENetics Interface Exploration (MRI-GENIE) study.& para;& para;Methods: MRI-GENIE capitalizes on the existing infrastructure of the Stroke Genetics Network (SiGN). In total, 12 international SiGN sites contributed MRIs of 3,301 patients with AIS. Detailed clinical phenotyping with the web-based Causative Classification of Stroke (CCS) system and genome-wide genotyping data were available for all participants. Neuroimaging analyses include the manual and automated assessments of established MRI markers. A high-throughput MRI analysis pipeline for the automated assessment of cerebrovascular lesions on clinical scans will be developed in a subset of scans for both acute and chronic lesions, validated against gold standard, and applied to all available scans. The extracted neuroimaging phenotypes will improve characterization of acute and chronic cerebrovascular lesions in ischemic stroke, including CCS subtypes, and their effect on functional outcomes after stroke. Moreover, genetic testing will uncover variants associated with acute and chronic MRI manifestations of cerebrovascular disease.& para;& para;Conclusions: The MRI-GENIE study aims to develop, validate, and distribute the MRI analysis platform for scans acquired as part of clinical care for patients with AIS, which will lead to (1) novel genetic discoveries in ischemic stroke, (2) strategies for personalized stroke risk assessment, and (3) personalized stroke outcome assessment.
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| 9. |
- Giese, Anne Katrin, et al.
(författare)
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Design and rationale for examining neuroimaging genetics in ischemic stroke : The MRI-GENIE study
- 2017
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Ingår i: Neurology: Genetics. - 2376-7839. ; 3:5
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To describe the design and rationale for the genetic analysis of acute and chronic cerebrovascular neuroimaging phenotypes detected on clinical MRI in patients with acute ischemic stroke (AIS) within the scope of the MRI-GENetics Interface Exploration (MRI-GENIE) study. Methods: MRI-GENIE capitalizes on the existing infrastructure of the Stroke Genetics Network (SiGN). In total, 12 international SiGN sites contributedMRIs of 3,301 patients with AIS. Detailed clinical phenotyping with the web-based Causative Classification of Stroke (CCS) system and genome-wide genotyping data were available for all participants. Neuroimaging analyses include themanual and automated assessments of established MRI markers. A high-throughputMRI analysis pipeline for the automated assessment of cerebrovascular lesions on clinical scans will be developed in a subset of scans for both acute and chronic lesions, validated against gold standard, and applied to all available scans. The extracted neuroimaging phenotypes will improve characterization of acute and chronic cerebrovascular lesions in ischemic stroke, including CCS subtypes, and their effect on functional outcomes after stroke. Moreover, genetic testing will uncover variants associated with acute and chronic MRI manifestations of cerebrovascular disease.Conclusions: The MRI-GENIE study aims to develop, validate, and distribute the MRI analysis platform for scans acquired as part of clinical care for patients with AIS, which will lead to (1) novel genetic discoveries in ischemic stroke, (2) strategies for personalized stroke risk assessment, and (3) personalized stroke outcome assessment.
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| 10. |
- Gorcenco, Sorina, et al.
(författare)
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Ataxia-pancytopenia syndrome with SAMD9L mutations
- 2017
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Ingår i: Neurology: Genetics. - 2376-7839. ; 3:5
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: We describe the neurologic, neuroradiologic, and ophthalmologic phenotype of 1 Swedish and 1 Finnish family with autosomal dominant ataxia-pancytopenia (ATXPC) syndrome and SAMD9L mutations.METHODS: Members of these families with germline SAMD9L c.2956C>T, p.Arg986Cys, or c.2672T>C, p.Ile891Thr mutations underwent structured interviews and neurologic and ophthalmologic examinations. Neuroimaging was performed, and medical records were reviewed. Previous publications on SAMD9L-ATXPC were reviewed.RESULTS: Twelve individuals in both families were affected clinically. All mutation carriers examined had balance impairment, although severity was very variable. All but 1 had nystagmus, and all but 1 had pyramidal tract signs. Neurologic features were generally present from childhood on and progressed slowly. Two adult patients, who experienced increasing clumsiness, glare, and difficulties with gaze fixation, had paracentral retinal dysfunction verified by multifocal electroretinography. Brain MRI showed early, marked cerebellar atrophy in most carriers and variable cerebral periventricular white matter T2 hyperintensities. Two children were treated with hematopoietic stem cell transplantation for hematologic malignancies, and the neurologic symptoms of one of these worsened after treatment. Three affected individuals had attention deficit hyperactivity disorder or cognitive problems. Retinal dysfunction was not previously reported in individuals with ATXPC.CONCLUSIONS: The neurologic phenotype of this syndrome is defined by balance or gait impairment, nystagmus, hyperreflexia in the lower limbs and, frequently, marked cerebellar atrophy. Paracentral retinal dysfunction may contribute to glare, reading problems, and clumsiness. Timely diagnosis of ATXPC is important to address the risk for severe hemorrhage, infection, and hematologic malignancies inherent in this syndrome; regular hematologic follow-up might be beneficial.
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| 11. |
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| 12. |
- Ilinca, Andreea, et al.
(författare)
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MAP3K6 Mutations in a Neurovascular Disease Causing Stroke, Cognitive Impairment, and Tremor
- 2021
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Ingår i: Neurology: Genetics. - 2376-7839. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To describe a possible novel genetic mechanism for cerebral small vessel disease (cSVD) and stroke.Methods: We studied a Swedish kindred with ischemic stroke and intracerebral hemorrhage, tremor, dysautonomia, and mild cognitive decline. Members were examined clinically, radiologically, and by histopathology. Genetic workup included whole-exome sequencing (WES) and whole-genome sequencing (WGS) and intrafamilial cosegregation analyses.Results: Fifteen family members were examined clinically. Twelve affected individuals had white matter hyperintensities and 1 or more of (1) stroke episodes, (2) clinically silent lacunar ischemic lesions, and (3) cognitive dysfunction. All affected individuals had tremor and/or atactic gait disturbance. Mild symmetric basal ganglia calcifications were seen in 3 affected members. Postmortem examination of 1 affected member showed pathologic alterations in both small and large arteries the brain. Skin biopsies of 3 affected members showed extracellular amorphous deposits within the subepidermal zone, which may represent degenerated arterioles. WES or WGS did not reveal any potentially disease-causing variants in known genes for cSVDs or idiopathic basal ganglia calcification, but identified 1 heterozygous variant, NM_004672.4 MAP3K6 c.322G>A p.(Asp108Asn), that cosegregated with the disease in this large family. MAP3K6 has known functions in angiogenesis and affects vascular endothelial growth factor expression, which may be implicated in cerebrovascular disease.Conclusions: Our data strongly suggest the MAP3K6 variant to be causative for this novel disease phenotype, but the absence of functional data and the present lack of additional families with this disease and MAP3K6 mutations still limit the formal evidence for the variant's pathogenicity.
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| 13. |
- Ilinca, A., et al.
(författare)
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MAP3K6 Mutations in a Neurovascular Disease Causing Stroke, Cognitive Impairment, and Tremor
- 2021
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Ingår i: Neurology-Genetics. - : Ovid Technologies (Wolters Kluwer Health). - 2376-7839. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- Objective To describe a possible novel genetic mechanism for cerebral small vessel disease (cSVD) and stroke. Methods We studied a Swedish kindred with ischemic stroke and intracerebral hemorrhage, tremor, dysautonomia, and mild cognitive decline. Members were examined clinically, radiologically, and by histopathology. Genetic workup included whole-exome sequencing (WES) and whole-genome sequencing (WGS) and intrafamilial cosegregation analyses. Results Fifteen family members were examined clinically. Twelve affected individuals had white matter hyperintensities and 1 or more of (1) stroke episodes, (2) clinically silent lacunar ischemic lesions, and (3) cognitive dysfunction. All affected individuals had tremor and/or atactic gait disturbance. Mild symmetric basal ganglia calcifications were seen in 3 affected members. Postmortem examination of 1 affected member showed pathologic alterations in both small and large arteries the brain. Skin biopsies of 3 affected members showed extracellular amorphous deposits within the subepidermal zone, which may represent degenerated arterioles. WES or WGS did not reveal any potentially disease-causing variants in known genes for cSVDs or idiopathic basal ganglia calcification, but identified 1 heterozygous variant, NM_004672.4 MAP3K6 c.322G>A p.(Asp108Asn), that cosegregated with the disease in this large family. MAP3K6 has known functions in angiogenesis and affects vascular endothelial growth factor expression, which may be implicated in cerebrovascular disease. Conclusions Our data strongly suggest the MAP3K6 variant to be causative for this novel disease phenotype, but the absence of functional data and the present lack of additional families with this disease and MAP3K6 mutations still limit the formal evidence for the variant's pathogenicity.
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| 14. |
- Johansson, Malin, et al.
(författare)
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Genetic Predisposition to Mosaic Chromosomal Loss Is Associated with Functional Outcome after Ischemic Stroke
- 2021
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Ingår i: Neurology: Genetics. - 2376-7839. ; 7:6
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Tidskriftsartikel (refereegranskat)abstract
- Background and ObjectivesTo test the hypothesis that a predisposition to acquired genetic alterations is associated with ischemic stroke outcome by investigating the association between a polygenic risk score (PRS) for mosaic loss of chromosome Y (mLOY) and outcome in a large international data set.MethodsWe used data from the genome-wide association study performed within the Genetics of Ischemic Stroke Functional Outcome network, which included 6,165 patients (3,497 men and 2,668 women) with acute ischemic stroke of mainly European ancestry. We assessed a weighted PRS for mLOY and examined possible associations with the modified Rankin Scale (mRS) score 3 months poststroke in logistic regression models. We investigated the whole study sample as well as men and women separately.ResultsIncreasing PRS for mLOY was associated with poor functional outcome (mRS score >2) with an odds ratio (OR) of 1.11 (95% confidence interval [CI] 1.03-1.19) per 1 SD increase in the PRS after adjustment for age, sex, ancestry, stroke severity (NIH Stroke Scale), smoking, and diabetes mellitus. In sex-stratified analyses, we found a statistically significant association in women (adjusted OR 1.20, 95% CI 1.08-1.33). In men, the association was in the same direction (adjusted OR 1.04, 95% CI 0.95-1.14), and we observed no significant genotype-sex interaction.DiscussionIn this exploratory study, we found associations between genetic variants predisposing to mLOY and stroke outcome. The significant association in women suggests underlying mechanisms related to genomic instability that operate in both sexes. These findings need replication and mechanistic exploration.
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| 15. |
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| 16. |
- Lee, Richard G., et al.
(författare)
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Early-onset Parkinson disease caused by a mutation in CHCHD2 and mitochondrial dysfunction
- 2018
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Ingår i: Neurology Genetics. - : Wolters Kluwer. - 2376-7839. ; 4:5
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Tidskriftsartikel (refereegranskat)abstract
- Objective Our goal was to identify the gene(s) associated with an early-onset form of Parkinson disease (PD) and the molecular defects associated with this mutation. Methods We combined whole-exome sequencing and functional genomics to identify the genes associated with early-onset PD. We used fluorescence microscopy, cell, and mitochondrial biology measurements to identify the molecular defects resulting from the identified mutation. Results Here, we report an association of a homozygous variant in CHCHD2, encoding coiled-coil-helix-coiled-coil-helix domain containing protein 2, a mitochondrial protein of unknown function, with an early-onset form of PD in a 26-year-old Caucasian woman. The CHCHD2 mutation in PD patient fibroblasts causes fragmentation of the mitochondrial reticular morphology and results in reduced oxidative phosphorylation at complex I and complex IV. Although patient cells could maintain a proton motive force, reactive oxygen species production was increased, which correlated with an increased metabolic rate. Conclusions Our findings implicate CHCHD2 in the pathogenesis of recessive early-onset PD, expanding the repertoire of mitochondrial proteins that play a direct role in this disease.
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| 17. |
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| 18. |
- Niemelä, Valter, et al.
(författare)
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Phenotypic variability in chorea-acanthocytosis associated with novel VPS13A mutations
- 2020
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Ingår i: NEUROLOGY-GENETICS. - : LIPPINCOTT WILLIAMS & WILKINS. - 2376-7839. ; 6:3
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Tidskriftsartikel (refereegranskat)abstract
- ObjectiveTo perform a comprehensive characterization of a cohort of patients with chorea-acanthocytosis (ChAc) in Sweden.MethodsClinical assessments, targeted genetic studies, neuroimaging with MRI, [F-18]-fluorodeoxyglucose (FDG) PET, and dopamine transporter with I-123 FP-CIT (DaTscan) SPECT. One patient underwent magnetic resonance spectroscopy (MRS).ResultsFour patients living in Sweden but with different ethnical backgrounds were included. Their clinical features were variable. Biallelic VPS13A mutations were confirmed in all patients, including 3 novel mutations. All tested patients had either low or absent chorein levels. One patient had progressive caudate atrophy. Investigation using FDG-PET revealed severe bilateral striatal hypometabolism, and DaTscan SPECT displayed presynaptic dopaminergic deficiency in 3 patients. MRS demonstrated reduced N-acetylaspartate/creatine (Cr) ratio and mild elevation of both choline/Cr and combined glutamate and glutamine/Cr in the striatum in 1 case. One patient died during sleep, and another was treated with deep brain stimulation, which transiently attenuated feeding dystonia but not his gait disorder or chorea.ConclusionsLarger longitudinal neuroimaging studies with different modalities, particularly MRS, are needed to determine their potential role as biomarkers for ChAc.
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| 19. |
- Nmezi, Bruce, et al.
(författare)
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Genomic deletions upstream of lamin B1 lead to atypical autosomal dominant leukodystrophy
- 2019
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Ingår i: NEUROLOGY-GENETICS. - 2376-7839. ; 5:1
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Tidskriftsartikel (refereegranskat)abstract
- Objective Clinical, radiologic, and molecular analysis of patients with genomic deletions upstream of the LMNB1 gene.Methods Detailed neurologic, MRI examinations, custom array comparative genomic hybridization (aCGH) analysis, and expression analysis were performed in patients at different clinical centers. All procedures were approved by institutional review boards of the respective institutions.Results Five patients from 3 independent families presented at ages ranging from 32 to 52 years with neurologic symptoms that included progressive hypophonia, upper and lower limb weakness and spasticity, and cerebellar dysfunction and MRIs characterized by widespread white matter alterations. Patients had unique nonrecurrent deletions upstream of the LMNB1, varying in size from 250 kb to 670 kb. Deletion junctions were embedded in repetitive elements. Expression analysis revealed increased LMNB1 expression in patient cells.Conclusions Our findings confirmed the association between LMNB1 upstream deletions and leukodystrophy previously reported in a single family, expanding the phenotypic and molecular description of this condition. Although clinical and radiologic features overlapped with those of autosomal dominant leukodystrophy because of LMNB1 duplications, patients with deletions upstream of LMNB1 had an earlier age at symptom onset, lacked early dysautonomia, and appeared to have lesser involvement of the cerebellum and sparing of the spinal cord diameter on MRI. aCGH analysis defined a smaller minimal critical region required for disease causation and revealed that deletions occur at repetitive DNA genomic elements. Search for LMNB1 structural variants (duplications and upstream deletions) should be an integral part of the investigation of patients with autosomal dominant adult-onset leukodystrophy.
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| 20. |
- Oldfors Hedberg, Carola, 1969, et al.
(författare)
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Carey-Fineman-Ziter syndrome with mutations in the myomaker gene and muscle fiber hypertrophy
- 2018
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Ingår i: Neurology-Genetics. - : Ovid Technologies (Wolters Kluwer Health). - 2376-7839. ; 4:4
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Tidskriftsartikel (refereegranskat)abstract
- Objective To describe the long-term clinical follow-up in 3 siblings with Carey-Fineman-Ziter syndrome (CFZS), a form of congenital myopathy with a novel mutation in the myomaker gene (MYMK). We performed clinical investigations, repeat muscle biopsy in 2 of the siblings at ages ranging from 11 months to 18 years, and whole-genome sequencing. All the siblings had a marked and characteristic facial weakness and variable dysmorphic features affecting the face, hands, and feet, and short stature. They had experienced muscle hypotonia and generalized muscle weakness since early childhood. The muscle biopsies revealed, as the only major abnormality at all ages, a marked hypertrophy of both type 1 and type 2 fibers with more than twice the diameter of that in age-matched controls. Genetic analysis revealed biallelic mutations in the MYMK gene, a novel c.235T>C; p.(Trp79Arg), and the previously described c.271C>A; p.(Pro91Thr). Our study expands the genetic and clinical spectrum of MYMK mutations and CFZS. The marked muscle fiber hypertrophy identified from early childhood, despite apparently normal muscle bulk, indicates that defective fusion of myoblasts during embryonic muscle development results in a reduced number of muscle fibers with compensatory hypertrophy and muscle weakness.
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| 21. |
- Oldfors Hedberg, Carola, 1969, et al.
(författare)
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COX deficiency and leukoencephalopathy due to a novel homozygous APOPT1/COA8 mutation
- 2020
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Ingår i: Neurology-Genetics. - : Ovid Technologies (Wolters Kluwer Health). - 2376-7839. ; 6:4
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Tidskriftsartikel (refereegranskat)abstract
- Objective To describe the long-term follow-up and pathogenesis in a child with leukoencephalopathy and cytochrome c oxidase (COX) deficiency due to a novel homozygous nonsense mutation in APOPT1/COA8. Methods The patient was clinically investigated at 3, 5, 9, and 25 years of age. Brain MRI, repeat muscle biopsies with biochemical, morphologic, and protein expression analyses were performed, and whole-genome sequencing was used for genetic analysis. Results Clinical investigation revealed dysarthria, dysphagia, and muscle weakness following pneumonia at age 3 years. There was clinical regression leading to severe loss of ambulation, speech, swallowing, hearing, and vision. The clinical course stabilized after 2.5 years and improved over time. The MRI pattern in the patient demonstrated cavitating leukoencephalopathy, and muscle mitochondrial investigations showed COX deficiency with loss of complex IV subunits and ultrastructural abnormalities. Genetic analysis revealed a novel homozygous mutation in the APOPT1/COA8 gene, c.310T>C; p.(Gln104*). Conclusions We describe a novel nonsense mutation in APOPT1/COA8 and provide additional experimental evidence for a COX assembly defect in human muscle causing the complex IV deficiency. The long-term outcome of the disease seems in general to be favorable, and the characteristic MRI pattern with cavitating leukoencephalopathy in combination with COX deficiency should prompt for testing of the APOPT1/COA8 gene.
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| 22. |
- Oldfors Hedberg, Carola, 1969, et al.
(författare)
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Deep sequencing of mitochondrial DNA and characterization of a novel POLG mutation in a patient with arPEO.
- 2020
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Ingår i: Neurology. Genetics. - 2376-7839. ; 6:1
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Tidskriftsartikel (refereegranskat)abstract
- To determine the pathogenicity of a novel POLG mutation in a man with late-onset autosomal recessive progressive external ophthalmoplegia using clinical, molecular, and biochemical analyses.A multipronged approach with detailed neurologic examinations, muscle biopsy analyses, molecular genetic studies, and in vitro biochemical characterization.The patient had slowly progressive bilateral ptosis and severely reduced horizontal and vertical gaze. Muscle biopsy showed slight variability in muscle fiber size, scattered ragged red fibers, and partial cytochrome c oxidase deficiency. Biallelic mutations were identified in the POLG gene encoding the catalytic A subunit of POLγ. One allele carried a novel mutation in the exonuclease domain (c.590T>C; p.F197S), and the other had a previously characterized null mutation in the polymerase domain (c.2740A>C; p.T914P). Biochemical characterization revealed that the novel F197S mutant protein had reduced exonuclease and DNA polymerase activities and confirmed that T914P was inactive. By deep sequencing of mitochondrial DNA (mtDNA) extracted from muscle, multiple large-scale rearrangements were mapped and quantified.The patient's phenotype was caused by biallelic POLG mutations, resulting in one inactive POLγA protein (T914P) and one with decreased polymerase and exonuclease activity (F197S). The reduction in polymerase activity explains the presence of multiple pathogenic large-scale deletions in the patient's mtDNA.
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| 27. |
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| 28. |
- Paucar, Martin, et al.
(författare)
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V374A KCND3 Pathogenic Variant Associated With Paroxysmal Ataxia Exacerbations
- 2021
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Ingår i: Neurology Genetics. - : American Academy of Neurology. - 2376-7839. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Ataxia channelopathies share common features such as slow motor progression and variable degrees of cognitive dysfunction. Mutations in potassium voltage-gated channel subfamily D member 3 (KCND3), encoding the K+ channel, Kv4.3, are associated with spinocerebellar ataxia (SCA) 19, allelic with SCA22. Mutations in potassium voltage-gated channel subfamily C member 3 (KCNC3), encoding another K+ channel, Kv3.3, cause SCA13. First, a comprehensive phenotype assessment was carried out in a family with autosomal dominant ataxia harboring 2 genetic variants in KCNC3 and KCND3. To evaluate the physiological impact of these variants on channel currents, in vitro studies were performed.Methods: Clinical and psychometric evaluations, neuroimaging, and genotyping of a family (mother and son) affected by ataxia were carried out. Heterozygous and homozygous Kv3.3 A671V and Kv4.3 V374A variants were evaluated in Xenopus laevis oocytes using 2-electrode voltage-clamp. The influence of Kv4 conductance on neuronal activity was investigated computationally using a Purkinje neuron model.Results: The main clinical findings were consistent with adult-onset ataxia with cognitive dysfunction and acetazolamide-responsive paroxysmal motor exacerbations in the index case. Despite cognitive deficits, fluorodeoxyglucose (FDG)-PET displayed hypometabolism mainly in the severely atrophic cerebellum. Genetic analyses revealed the new variant c.1121T>C (V374A) in KCND3 and c.2012T>C (A671V) in KCNC3. In vitro electrophysiology experiments on Xenopus oocytes demonstrated that the V374A mutant was nonfunctional when expressed on its own. Upon equal co-expression of wild-type (WT) and V374A channel subunits, Kv4.3 currents were significantly reduced in a dominant negative manner, without alterations of the gating properties of the channel. By contrast, Kv3.3 A671V, when expressed alone, exhibited moderately reduced currents compared with WT, with no effects on channel activation or inactivation. Immunohistochemistry demonstrated adequate cell membrane translocation of the Kv4.3 V374A variant, thus suggesting an impairment of channel function, rather than of expression. Computational modeling predicted an increased Purkinje neuron firing frequency upon reduced Kv4.3 conductance.Conclusions: Our findings suggest that Kv4.3 V374A is likely pathogenic and associated with paroxysmal ataxia exacerbations, a new trait for SCA19/22. The present FDG PET findings contrast with a previous study demonstrating widespread brain hypometabolism in SCA19/22.
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| 29. |
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| 30. |
- Pulit, S. L., et al.
(författare)
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Atrial fibrillation genetic risk differentiates cardioembolic stroke from other stroke subtypes
- 2018
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Ingår i: Neurology-Genetics. - : Ovid Technologies (Wolters Kluwer Health). - 2376-7839. ; 4:6
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Tidskriftsartikel (refereegranskat)abstract
- Objective We sought to assess whether genetic risk factors for atrial fibrillation (AF) can explain cardioembolic stroke risk. We evaluated genetic correlations between a previous genetic study of AF and AF in the presence of cardioembolic stroke using genome-wide genotypes from the Stroke Genetics Network (N = 3,190 AF cases, 3,000 cardioembolic stroke cases, and 28,026 referents). We tested whether a previously validated AF polygenic risk score (PRS) associated with cardioembolic and other stroke subtypes after accounting for AF clinical risk factors. We observed a strong correlation between previously reported genetic risk for AF, AF in the presence of stroke, and cardioembolic stroke (Pearson r = 0.77 and 0.76, respectively, across SNPs with p < 4.4 x 10(-4) in the previous AF meta-analysis). An AF PRS, adjusted for clinical AF risk factors, was associated with cardioembolic stroke (odds ratio [OR] per SD = 1.40, p = 1.45 x 10(-48)), explaining similar to 20% of the heritable component of cardioembolic stroke risk. The AF PRS was also associated with stroke of undetermined cause (OR per SD = 1.07,p = 0.004), but no other primary stroke subtypes (all p > 0.1). Genetic risk of AF is associated with cardioembolic stroke, independent of clinical risk factors. Studies are warranted to determine whether AF genetic risk can serve as a biomarker for strokes caused by AF.
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| 31. |
- Reinthaler, Eva M., et al.
(författare)
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TPP2 mutation associated with sterile brain inflammation mimicking MS
- 2018
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Ingår i: NEUROLOGY-GENETICS. - 2376-7839. ; 4:6
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Tidskriftsartikel (refereegranskat)abstract
- Objective To ascertain the genetic cause of a consanguineous family from Syria suffering from a sterile brain inflammation mimicking a mild nonprogressive form of MS.Methods We used homozygosity mapping and next-generation sequencing to detect the disease-causing gene in the affected siblings. In addition, we performed RNA and protein expression studies, enzymatic activity assays, immunohistochemistry, and targeted sequencing of further MS cases from Austria, Germany, Canada and Jordan.Results In this study, we describe the identification of a homozygous missense mutation (c.82T>G, p.Cys28Gly) in the tripeptidyl peptidase II (TPP2) gene in all 3 affected siblings of the family. Sequencing of all TPP2-coding exons in 826 MS cases identified one further homozygous missense variant (c.2027C>T, p.Thr676Ile) in a Jordanian MS patient. TPP2 protein expression in whole blood was reduced in the affected siblings. In contrast, TPP2 protein expression in postmortem brain tissue from MS patients without TPP2 mutations was highly upregulated.Conclusions The homozygous TPP2 mutation (p.Cys28Gly) is likely responsible for the inflammation phenotype in this family. TPP2 is an ubiquitously expressed serine peptidase that removes tripeptides from the N-terminal end of longer peptides. TPP2 is involved in various biological processes including the destruction of major histocompatibility complex Class I epitopes. Recessive loss-of-function mutations in TPP2 were described in patients with Evans syndrome, a rare autoimmune disease affecting the hematopoietic system. Based on the gene expression results in our MS autopsy brain samples, we further suggest that TPP2 may play a broader role in the inflammatory process in MS.
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| 32. |
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| 33. |
- Sedghi, Maryam, et al.
(författare)
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Ataxia-telangiectasia-like disorder in a family deficient for MRE11A, caused by a MRE11 variant
- 2018
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Ingår i: Neurology: Genetics. - : Lippincott Williams & Wilkins. - 2376-7839. ; 4:6
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Tidskriftsartikel (refereegranskat)abstract
- Objective We report 3 siblings with the characteristic features of ataxia-telangiectasia-like disorder associated with a homozygous MRE11 synonymous variant causing nonsense-mediated mRNA decay (NMD) and MRE11A deficiency. Methods Clinical assessments, next-generation sequencing, transcript and immunohistochemistry analyses were performed. Results The patients presented with poor balance, developmental delay during the first year of age, and suffered from intellectual disability from early childhood. They showed oculomotor apraxia, slurred and explosive speech, limb and gait ataxia, exaggerated deep tendon reflex, dystonic posture, and mirror movement in their hands. They developed mild cognitive abilities. Brain MRI in the index case revealed cerebellar atrophy. Next-generation sequencing revealed a homozygous synonymous variant in MRE11 (c.657C>T, p.Asn219=) that we show affects splicing. A complete absence of MRE11 transcripts in the index case suggested NMD and immunohistochemistry confirmed the absence of a stable protein. Conclusions Despite the critical role of MRE11A in double-strand break repair and its contribution to the Mre11/Rad50/Nbs1 complex, the absence of MRE11A is compatible with life.
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| 34. |
- Sedghi, M., et al.
(författare)
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Ataxia-telangiectasia-like disorder in a family deficient for MRE11A, caused by a MRE11 variant
- 2018
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Ingår i: Neurology-Genetics. - : Ovid Technologies (Wolters Kluwer Health). - 2376-7839. ; 4:6
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Tidskriftsartikel (refereegranskat)abstract
- Objective We report 3 siblings with the characteristic features of ataxia-telangiectasia-like disorder associated with a homozygous MREll synonymous variant causing nonsense-mediated mRNA decay (NMD) and MRE11A deficiency. Clinical assessments, next-generation sequencing, transcript and immunohistochemistry analyses were performed. The patients presented with poor balance, developmental delay during the first year of age, and suffered from intellectual disability from early childhood. They showed oculomotor apraxia, slurred and explosive speech, limb and gait ataxia, exaggerated deep tendon reflex, dystonic posture, and mirror movement in their hands. They developed mild cognitive abilities. Brain MRI in the index case revealed cerebellar atrophy. Next-generation sequencing revealed a homozygous synonymous variant in MRE11 (c.657C>T, p.Asn219=) that we show affects splicing. A complete absence of MREll transcripts in the index case suggested NMD and immunohistochemistry confirmed the absence of a stable protein. Despite the critical role of MRE11A in double-strand break repair and its contribution to the Mre11/Rad50/Nbs1 complex, the absence of MRE11A is compatible with life.
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- Vihola, Anna, et al.
(författare)
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Novel mutation in TNPO3 causes congenital limb-girdle myopathy with slow progression
- 2019
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Ingår i: NEUROLOGY-GENETICS. - : LIPPINCOTT WILLIAMS & WILKINS. - 2376-7839. ; 5:3
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Tidskriftsartikel (refereegranskat)abstract
- Objective We report a second family with autosomal dominant transportinopathy presenting with congenital or early-onset myopathy and slow progression, causing proximal and less pronounced distal muscle weakness. Methods Patients had clinical examinations, muscle MRI, EMG, and muscle biopsy studies. The MYOcap gene panel was used to identify the gene defect in the family. Muscle biopsies were used for histopathologic and protein expression studies, and TNPO3 constructs were used to study the effect of the mutations in transfected cells. Results We identified a novel heterozygous mutation, c.2757delC, in the last part of the transportin-3 (TNPO3) gene in the affected family members. The mutation causes an almost identical frameshift affecting the stop codon and elongating the C-term protein product of the TNPO3 transcript, as was previously reported in the first large Spanish-Italian LGMD1F kindred. TNPO3 protein was increased in the patient muscle and accumulated in the subsarcolemmal and perinuclear areas. At least one of the cargo proteins, the splicing factor SRRM2 was normally located in the nucleus. Transiently transfected mutant TNPO3 constructs failed to localize to cytoplasmic annulate lamellae pore complexes in cells. Conclusions We report the clinical, molecular genetic, and histopathologic features of the second transportinopathy family. The variability of the clinical phenotype together with histopathologic findings suggests that several molecular pathways may be involved in the disease pathomechanism, such as nucleocytoplasmic shuttling, protein aggregation, and defective protein turnover.
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