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Duan X, Wang H, Cao Z, Su N, Wang Y, Zheng Y. Deficiency of ValRS-m Causes Male Infertility in Drosophila melanogaster. Int J Mol Sci 2024; 25:7489. [PMID: 39000597 PMCID: PMC11242588 DOI: 10.3390/ijms25137489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2024] [Revised: 06/25/2024] [Accepted: 07/01/2024] [Indexed: 07/16/2024] Open
Abstract
Drosophila spermatogenesis involves the renewal of germline stem cells, meiosis of spermatocytes, and morphological transformation of spermatids into mature sperm. We previously demonstrated that Ocnus (ocn) plays an essential role in spermatogenesis. The ValRS-m (Valyl-tRNA synthetase, mitochondrial) gene was down-regulated in ocn RNAi testes. Here, we found that ValRS-m-knockdown induced complete sterility in male flies. The depletion of ValRS-m blocked mitochondrial behavior and ATP synthesis, thus inhibiting the transition from spermatogonia to spermatocytes, and eventually, inducing the accumulation of spermatogonia during spermatogenesis. To understand the intrinsic reason for this, we further conducted transcriptome-sequencing analysis for control and ValRS-m-knockdown testes. The differentially expressed genes (DEGs) between these two groups were selected with a fold change of ≥2 or ≤1/2. Compared with the control group, 4725 genes were down-regulated (dDEGs) and 2985 genes were up-regulated (uDEGs) in the ValRS-m RNAi group. The dDEGs were mainly concentrated in the glycolytic pathway and pyruvate metabolic pathway, and the uDEGs were primarily related to ribosomal biogenesis. A total of 28 DEGs associated with mitochondria and 6 meiosis-related genes were verified to be suppressed when ValRS-m was deficient. Overall, these results suggest that ValRS-m plays a wide and vital role in mitochondrial behavior and spermatogonia differentiation in Drosophila.
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Affiliation(s)
- Xin Duan
- School of Life Sciences, Central China Normal University, Wuhan 430079, China; (X.D.); (H.W.); (Z.C.); (Y.W.)
| | - Haolin Wang
- School of Life Sciences, Central China Normal University, Wuhan 430079, China; (X.D.); (H.W.); (Z.C.); (Y.W.)
| | - Zhixian Cao
- School of Life Sciences, Central China Normal University, Wuhan 430079, China; (X.D.); (H.W.); (Z.C.); (Y.W.)
| | - Na Su
- School of Life Sciences, Shanghai Normal University, Shanghai 200234, China;
| | - Yufeng Wang
- School of Life Sciences, Central China Normal University, Wuhan 430079, China; (X.D.); (H.W.); (Z.C.); (Y.W.)
| | - Ya Zheng
- School of Life Sciences, Shanghai Normal University, Shanghai 200234, China;
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Kong LY, Wu YZ, Cheng RQ, Wang PH, Peng BW. Role of Mutations of Mitochondrial Aminoacyl-tRNA Synthetases Genes on Epileptogenesis. Mol Neurobiol 2023; 60:5482-5492. [PMID: 37316759 DOI: 10.1007/s12035-023-03429-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 06/05/2023] [Indexed: 06/16/2023]
Abstract
Mitochondria are the structures in cells that are responsible for producing energy. They contain a specific translation unit for synthesizing mitochondria-encoded respiratory chain components: the mitochondrial DNA (mt DNA). Recently, a growing number of syndromes associated with the dysfunction of mt DNA translation have been reported. However, the functions of these diseases still need to be precise and thus attract much attention. Mitochondrial tRNAs (mt tRNAs) are encoded by mt DNA; they are the primary cause of mitochondrial dysfunction and are associated with a wide range of pathologies. Previous research has shown the role of mt tRNAs in the epileptic mechanism. This review will focus on the function of mt tRNA and the role of mitochondrial aminoacyl-tRNA synthetase (mt aaRS) in order to summarize some common relevant mutant genes of mt aaRS that cause epilepsy and the specific symptoms of the disease they cause.
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Affiliation(s)
- Ling-Yue Kong
- Department of Physiology, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Yi-Ze Wu
- Department of Physiology, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Run-Qi Cheng
- Department of Physiology, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Pei-Han Wang
- Department of Physiology, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Bi-Wen Peng
- Department of Physiology, School of Basic Medical Sciences, Wuhan University, Wuhan, China.
- Department of Physiology, Hubei Provincial Key Laboratory of Developmentally Originated Disease, School of Basic Medical Sciences, Wuhan University, Donghu Rd185#, Wuhan, 430071, Hubei, China.
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Wu XH, Lin SZ, Zhou YQ, Wang WQ, Li JY, Chen QD. VARS2 gene mutation leading to overall developmental delay in a child with epilepsy: A case report. World J Clin Cases 2022; 10:8749-8754. [PMID: 36157797 PMCID: PMC9453344 DOI: 10.12998/wjcc.v10.i24.8749] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 07/02/2022] [Accepted: 07/22/2022] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND The mitochondrial respiratory chain defects have become the most common cause of neurometabolic disorders in children and adults, which can occur at any time in life, often associated with neurological dysfunction, and lead to chronic disability and premature death. Approximately one-third of patients with mitochondrial disease have biochemical defects involving multiple respiratory chain complexes, suggesting defects in protein synthesis within the mitochondria. We here report a child with VARS2 gene mutations causing mitochondrial disease.
CASE SUMMARY A girl, aged 3 years and 4 mo, had been unable to sit and crawl alone since birth, with obvious seizures and microcephaly. Brain magnetic resonance imaging showed symmetrical, flaky, long T1-weighted and low T2-weighted signals in the posterior part of the bilateral putamen with a high signal shadow. T2 fluid-attenuated inversion recovery imaging showed a slightly high signal and diffusion-weighted imaging showed an obvious high signal. Whole-exome gene sequencing revealed a compound heterozygous mutation in the VARS2 gene, c.1163(exon11)C>T and c.1940(exon20)C>T, which was derived from the parents. The child was diagnosed with combined oxidative phosphorylation deficiency type 20.
CONCLUSION In this patient, mitochondrial disorders including Leigh syndrome and MELAS syndrome (mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes) were ruled out, and combined oxidative phosphorylation deficiency type 20 was diagnosed, expanding the phenotypic spectrum of the disease.
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Affiliation(s)
- Xiao-Hui Wu
- Department of Neurology, Quanzhou Children's Hospital, Quanzhou 362000, Fujian Province, China
| | - Shuang-Zhu Lin
- Diagnosis and Treatment Center for Children, The Affiliated Hospital of Changchun University of Chinese Medicine, Changchun 130103, Jilin Province, China
| | - Yan-Qiu Zhou
- Diagnosis and Treatment Center for Children, The Affiliated Hospital of Changchun University of Chinese Medicine, Changchun 130103, Jilin Province, China
| | - Wan-Qi Wang
- Pediatrics of Traditional Chinese Medicine, College of Traditional Chinese Medicine, Changchun University of Chinese Medicine, Changchun 130117, Jilin province, China
| | - Jia-Yi Li
- Pediatrics of Traditional Chinese Medicine, College of Traditional Chinese Medicine, Changchun University of Chinese Medicine, Changchun 130117, Jilin province, China
| | - Qian-Dui Chen
- College of Integrated Chinese and Western Medicine, Changchun University of Chinese Medicine, Changchun 130117, Jilin Province, China
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Hesam-Shariati S, Overs BJ, Roberts G, Toma C, Watkeys OJ, Green MJ, Pierce KD, Edenberg HJ, Wilcox HC, Stapp EK, McInnis MG, Hulvershorn LA, Nurnberger JI, Schofield PR, Mitchell PB, Fullerton JM. Epigenetic signatures relating to disease-associated genotypic burden in familial risk of bipolar disorder. Transl Psychiatry 2022; 12:310. [PMID: 35922419 PMCID: PMC9349272 DOI: 10.1038/s41398-022-02079-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 07/18/2022] [Accepted: 07/20/2022] [Indexed: 11/08/2022] Open
Abstract
Environmental factors contribute to risk of bipolar disorder (BD), but how environmental factors impact the development of psychopathology within the context of elevated genetic risk is unknown. We herein sought to identify epigenetic signatures operating in the context of polygenic risk for BD in young people at high familial risk (HR) of BD. Peripheral blood-derived DNA was assayed using Illumina PsychArray, and Methylation-450K or -EPIC BeadChips. Polygenic risk scores (PRS) were calculated using summary statistics from recent genome-wide association studies for BD, major depressive disorder (MDD) and cross-disorder (meta-analysis of eight psychiatric disorders). Unrelated HR participants of European ancestry (n = 103) were stratified based on their BD-PRS score within the HR-population distribution, and the top two quintiles (High-BD-PRS; n = 41) compared against the bottom two quintiles (Low-BD-PRS; n = 41). The High-BD-PRS stratum also had higher mean cross-disorder-PRS and MDD-PRS (ANCOVA p = 0.035 and p = 0.024, respectively). We evaluated DNA methylation differences between High-BD-PRS and Low-BD-PRS strata using linear models. One differentially methylated probe (DMP) (cg00933603; p = 3.54 × 10-7) in VARS2, a mitochondrial aminoacyl-tRNA synthetase, remained significantly hypomethylated after multiple-testing correction. Overall, BD-PRS appeared to broadly impact epigenetic processes, with 1,183 genes mapped to nominal DMPs (p < 0.05); these displayed convergence with genes previously associated with BD, schizophrenia, chronotype, and risk taking. We tested poly-methylomic epigenetic profiles derived from nominal DMPs in two independent samples (n = 54 and n = 82, respectively), and conducted an exploratory evaluation of the effects of family environment, indexing cohesion and flexibility. This study highlights an important interplay between heritable risk and epigenetic factors, which warrant further exploration.
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Affiliation(s)
- Sonia Hesam-Shariati
- Neuroscience Research Australia, Sydney, NSW, Australia
- School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
| | | | - Gloria Roberts
- School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
| | - Claudio Toma
- Neuroscience Research Australia, Sydney, NSW, Australia
- School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
- Centro de Biología Molecular "Severo Ochoa", Universidad Autónoma de Madrid/CSIC, Madrid, Spain
| | - Oliver J Watkeys
- Neuroscience Research Australia, Sydney, NSW, Australia
- School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
| | - Melissa J Green
- Neuroscience Research Australia, Sydney, NSW, Australia
- School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
| | | | - Howard J Edenberg
- Department of Medical and Molecular Genetics, Indiana University, Indianapolis, IN, USA
- Department of Biochemistry and Molecular Biology, Indiana University, Indianapolis, IN, USA
| | - Holly C Wilcox
- Child Psychiatry & Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Emma K Stapp
- Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
- National Institute of Mental Health, Bethesda, MD, USA
| | - Melvin G McInnis
- Department of Psychiatry, University of Michigan, Ann Arbor, MI, USA
| | - Leslie A Hulvershorn
- Department of Psychiatry, Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA
| | - John I Nurnberger
- Department of Medical and Molecular Genetics, Indiana University, Indianapolis, IN, USA
- Department of Psychiatry, Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Peter R Schofield
- Neuroscience Research Australia, Sydney, NSW, Australia
- School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
| | - Philip B Mitchell
- School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
| | - Janice M Fullerton
- Neuroscience Research Australia, Sydney, NSW, Australia.
- School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia.
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Vafaee-Shahi M, Farhadi M, Razmara E, Morovvati S, Ghasemi S, Abedini SS, Bagher Z, Alizadeh R, Falah M. Novel phenotype and genotype spectrum of NARS2 and literature review of previous mutations. Ir J Med Sci 2022; 191:1877-1890. [PMID: 34374940 DOI: 10.1007/s11845-021-02736-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 07/30/2021] [Indexed: 01/19/2023]
Abstract
BACKGROUND Mutations in NARS2 (MIM: 612803) are associated with combined oxidative phosphorylation deficiency 24 (COXPD24; MIM: 616239) that is a rare mitochondrial and a multisystem autosomal recessive disorder. AIMS We aimed to detect the underlying genetic factors in two siblings with progressive ataxia, epilepsy, and severe-to-profound hearing impairment. METHODS After doing medical assessments and pertinent tests (i.e., auditory brainstem responses, pure tone otoacoustic emission test, cardiac examinations, computed tomography, and electroencephalogram), because of the clinical and probable genetic heterogeneity, whole-exome sequencing was performed, and co-segregation analysis was confirmed by Sanger sequencing. Biological impacts of the novel variant were evaluated using sequence-to-function bioinformatics tools. RESULTS A novel homozygous missense variant, NM_024678.6:c.545 T > A; p.(Ile182Lys), in exon 5 of NARS2 was identified in both patients and verified by Sanger sequencing. In silico analyses introduced this variant as pathogenic. Mitral valve prolapses with mild regurgitation, brachymetatarsia, severe hallux valgus, and clubbed fingers were reported as novel manifestations in association with NARS2 gene. By doing a literature review, we also underscored the high heterogeneity of disease phenotype. CONCLUSIONS Herein, we report some novel phenotype and genotype features of two female patients in an Iranian consanguineous family with COXPD24, caused by a variant in NARS2-NM_024678.6: c.545 T > A; p.(Ile182Lys). Moreover, our data expanded the phenotype and genotype spectrum of NARS2-related disorder and confirmed an unpredictable nature of genotype-phenotype correlation in COXPD24.
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Affiliation(s)
- Mohammad Vafaee-Shahi
- ENT and Head and Neck Research Center and Department, The Five Senses Health Institute, Hazrat Rasoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran
- Pediatric Growth and Development Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Mohammad Farhadi
- ENT and Head and Neck Research Center and Department, The Five Senses Health Institute, Hazrat Rasoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran
| | - Ehsan Razmara
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Saeid Morovvati
- Department of Genetics, Faculty of Advanced Sciences and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Saeide Ghasemi
- Ali Asghar Children's Hospital, Iran University of Medical Sciences, Tehran, Iran
| | - Seyedeh Sedigheh Abedini
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Zohreh Bagher
- ENT and Head and Neck Research Center and Department, The Five Senses Health Institute, Hazrat Rasoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran
| | - Rafieh Alizadeh
- ENT and Head and Neck Research Center and Department, The Five Senses Health Institute, Hazrat Rasoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran
| | - Masoumeh Falah
- ENT and Head and Neck Research Center and Department, The Five Senses Health Institute, Hazrat Rasoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran.
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VARS2 Depletion Leads to Activation of the Integrated Stress Response and Disruptions in Mitochondrial Fatty Acid Oxidation. Int J Mol Sci 2022; 23:ijms23137327. [PMID: 35806332 PMCID: PMC9267100 DOI: 10.3390/ijms23137327] [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: 06/10/2022] [Revised: 06/28/2022] [Accepted: 06/29/2022] [Indexed: 11/26/2022] Open
Abstract
Mutations in mitochondrial aminoacyl-tRNA synthetases (mtARSs) have been reported in patients with mitochondriopathies: most commonly encephalopathy, but also cardiomyopathy. Through a GWAS, we showed possible associations between mitochondrial valyl-tRNA synthetase (VARS2) dysregulations and non-ischemic cardiomyopathy. We aimed to investigate the possible consequences of VARS2 depletion in zebrafish and cultured HEK293A cells. Transient VARS2 loss-of-function was induced in zebrafish embryos using Morpholinos. The enzymatic activity of VARS2 was measured in VARS2-depleted cells via northern blot. Heterozygous VARS2 knockout was established in HEK293A cells using CRISPR/Cas9 technology. BN-PAGE and SDS-PAGE were used to investigate electron transport chain (ETC) complexes, and the oxygen consumption rate and extracellular acidification rate were measured using a Seahorse XFe96 Analyzer. The activation of the integrated stress response (ISR) and possible disruptions in mitochondrial fatty acid oxidation (FAO) were explored using RT-qPCR and western blot. Zebrafish embryos with transient VARS2 loss-of-function showed features of heart failure as well as indications of CNS and skeletal muscle involvements. The enzymatic activity of VARS2 was significantly reduced in VARS2-depleted cells. Heterozygous VARS2-knockout cells showed a rearrangement of ETC complexes in favor of complexes III2, III2 + IV, and supercomplexes without significant respiratory chain deficiencies. These cells also showed the enhanced activation of the ISR, as indicated by increased eIF-2α phosphorylation and a significant increase in the transcript levels of ATF4, ATF5, and DDIT3 (CHOP), as well as disruptions in FAO. The activation of the ISR and disruptions in mitochondrial FAO may underlie the adaptive changes in VARS2-depleted cells.
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Kušíková K, Feichtinger RG, Csillag B, Kalev OK, Weis S, Duba HC, Mayr JA, Weis D. Case Report and Review of the Literature: A New and a Recurrent Variant in the VARS2 Gene Are Associated With Isolated Lethal Hypertrophic Cardiomyopathy, Hyperlactatemia, and Pulmonary Hypertension in Early Infancy. Front Pediatr 2021; 9:660076. [PMID: 33937156 PMCID: PMC8085550 DOI: 10.3389/fped.2021.660076] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 03/22/2021] [Indexed: 01/01/2023] Open
Abstract
Mitochondriopathies represent a wide spectrum of miscellaneous disorders with multisystem involvement, which are caused by various genetic changes. The establishment of the diagnosis of mitochondriopathy is often challenging. Recently, several mutations of the VARS2 gene encoding the mitochondrial valyl-tRNA synthetase were associated with early onset encephalomyopathies or encephalocardiomyopathies with major clinical features such as hypotonia, developmental delay, brain MRI changes, epilepsy, hypertrophic cardiomyopathy, and plasma lactate elevation. However, the correlation between genotype and phenotype still remains unclear. In this paper we present a male Caucasian patient with a recurrent c.1168G>A (p.Ala390Thr) and a new missense biallelic variant c.2758T>C (p.Tyr920His) in the VARS2 gene which were detected by whole exome sequencing (WES). VARS2 protein was reduced in the patient's muscle. A resulting defect of oxidative phosphorylation (OXPHOS) was proven by enzymatic assay, western blotting and immunohistochemistry from a homogenate of skeletal muscle tissue. Clinical signs of our patient included hyperlactatemia, hypertrophic cardiomyopathy (HCM) and pulmonary hypertension, which led to early death at the age of 47 days without any other known accompanying signs. The finding of novel variants in the VARS2 gene expands the spectrum of known mutations and phenotype presentation. Based on our findings we recommend to consider possible mitochondriopathy and to include the analysis of the VARS2 gene in the genetic diagnostic algorithm in cases with early manifesting and rapidly progressing HCM with hyperlactatemia.
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Affiliation(s)
- Katarína Kušíková
- Department of Pediatric Neurology, Medical School, Comenius University and National Institute of Children's Diseases, Bratislava, Slovakia
| | - René Günther Feichtinger
- Department of Pediatrics, University Hospital Salzburg, Paracelsus Medical University Salzburg, Salzburg, Austria
| | - Bernhard Csillag
- Department of Neonatology, Kepler University Hospital Med Campus IV, Johannes Kepler University Linz, Linz, Austria
| | - Ognian Kostadinov Kalev
- Division of Neuropathology, Department of Pathology and Molecular Pathology, Kepler University Hospital Neuromed Campus, Johannes Kepler University Linz, Linz, Austria
| | - Serge Weis
- Division of Neuropathology, Department of Pathology and Molecular Pathology, Kepler University Hospital Neuromed Campus, Johannes Kepler University Linz, Linz, Austria
| | - Hans-Christoph Duba
- Department of Medical Genetics, Kepler University Hospital Med Campus IV, Johannes Kepler University Linz, Linz, Austria
| | - Johannes Adalbert Mayr
- Department of Pediatrics, University Hospital Salzburg, Paracelsus Medical University Salzburg, Salzburg, Austria
| | - Denisa Weis
- Department of Medical Genetics, Kepler University Hospital Med Campus IV, Johannes Kepler University Linz, Linz, Austria
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