1
|
Zhang X, Xiang F, Li D, Yang F, Yu S, Wang X. Adult-onset combined oxidative phosphorylation deficiency type 14 manifests as epileptic status: a new phenotype and literature review. BMC Neurol 2024; 24:15. [PMID: 38166857 PMCID: PMC10759640 DOI: 10.1186/s12883-023-03480-4] [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: 05/24/2023] [Accepted: 11/27/2023] [Indexed: 01/05/2024] Open
Abstract
BACKGROUND Combined oxidative phosphorylation deficiency (COXPD) is a severe disorder with early onset and autosomal recessive inheritance, and has been divided into 51 types (COXPD1-COXPD51). COXPD14 is caused by a mutation in the FARS2 gene, which encodes mitochondrial phenylalanyl-tRNA synthetase (mt-PheRS), an enzyme that transfers phenylalanine to its cognate tRNA in mitochondria. Since the first case was reported in 2012, an increasing number of FARS2 variations have been subsequently identified, which present three main phenotypic manifestations: early onset epileptic encephalopathy, hereditary spastic paraplegia, and juvenile-onset epilepsy. To our knowledge, no adult cases have been reported in the literature. METHODS We report in detail a case of genetically confirmed COXPD14 and review the relevant literature. RESULTS Approximately 58 subjects with disease-causing variants of FARS2 have been reported, including 31 cases of early onset epileptic encephalopathy, 16 cases of hereditary spastic paraplegia, 3 cases of juvenile-onset epilepsy, and 8 cases of unknown phenotype. We report a case of autosomal recessive COXPD14 in an adult with status epilepticus as the only manifestation with a good prognosis, which is different from that in neonatal or infant patients reported in the literature. c.467C > T (p.T156M) has been previously reported, while c.119_120del (p.E40Vfs*87) is novel, and, both mutations are pathogenic. CONCLUSIONS This case of autosomal recessive COXPD14 in an adult only presented as status epilepticus, which is different from the patients reported previously. Our study expands the mutation spectrum of FARS2, and we tended to define the phenotypes based on the clinical manifestation rather than the age of onset.
Collapse
Affiliation(s)
- Xu Zhang
- Department of Neurology, The First Medical Center of Chinese PLA General Hospital, 28# Fuxing Road, Beijing, People's Republic of China
| | - Feng Xiang
- Department of Neurology, The First Medical Center of Chinese PLA General Hospital, 28# Fuxing Road, Beijing, People's Republic of China
| | - Desheng Li
- Department of Neurology, The First Medical Center of Chinese PLA General Hospital, 28# Fuxing Road, Beijing, People's Republic of China
| | - Fei Yang
- Department of Neurology, The First Medical Center of Chinese PLA General Hospital, 28# Fuxing Road, Beijing, People's Republic of China
| | - Shengyuan Yu
- Department of Neurology, The First Medical Center of Chinese PLA General Hospital, 28# Fuxing Road, Beijing, People's Republic of China
| | - Xiangqing Wang
- Department of Neurology, The First Medical Center of Chinese PLA General Hospital, 28# Fuxing Road, Beijing, People's Republic of China.
| |
Collapse
|
2
|
Chen W, Rehsi P, Thompson K, Yeo M, Stals K, He L, Schimmel P, Chrzanowska-Lightowlers ZMA, Wakeling E, Taylor RW, Kuhle B. Clinical and molecular characterization of novel FARS2 variants causing neonatal mitochondrial disease. Mol Genet Metab 2023; 140:107657. [PMID: 37523899 DOI: 10.1016/j.ymgme.2023.107657] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 07/22/2023] [Accepted: 07/22/2023] [Indexed: 08/02/2023]
Abstract
FARS2 encodes the mitochondrial phenylalanyl-tRNA synthetase (mtPheRS), which is essential for charging mitochondrial (mt-) tRNAPhe with phenylalanine for use in intramitochondrial translation. Many biallelic, pathogenic FARS2 variants have been described previously, which are mostly associated with two distinct clinical phenotypes; an early onset epileptic mitochondrial encephalomyopathy or a later onset spastic paraplegia. In this study, we report on a patient who presented at 3 weeks of age with tachypnoea and poor feeding, which progressed to severe metabolic decompensation with lactic acidosis and seizure activity followed by death at 9 weeks of age. Rapid trio whole exome sequencing identified compound heterozygous FARS2 variants including a pathogenic exon 2 deletion on one allele and a rare missense variant (c.593G > T, p.(Arg198Leu)) on the other allele, necessitating further work to aid variant classification. Assessment of patient fibroblasts demonstrated severely decreased steady-state levels of mtPheRS, but no obvious defect in any components of the oxidative phosphorylation system. To investigate the potential pathogenicity of the missense variant, we determined its high-resolution crystal structure, demonstrating a local structural destabilization in the catalytic domain. Moreover, the R198L mutation reduced the thermal stability and impaired the enzymatic activity of mtPheRS due to a lower binding affinity for tRNAPhe and a slower turnover rate. Together these data confirm the pathogenicity of this FARS2 variant in causing early-onset mitochondrial epilepsy.
Collapse
Affiliation(s)
- Wenqian Chen
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Preeya Rehsi
- Metabolic Unit, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Kyle Thompson
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle Upon Tyne NE2 4HH, UK
| | - Mildrid Yeo
- Metabolic Unit, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Karen Stals
- Exeter Genomics Laboratory, Royal Devon and Exeter NHS Foundation Trust, Exeter, UK
| | - Langping He
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle Upon Tyne NE2 4HH, UK; NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle Upon Tyne NE1 4LP, UK
| | - Paul Schimmel
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA; The Scripps Florida Research Institute at the University of Florida, Jupiter, FL 33458, USA
| | - Zofia M A Chrzanowska-Lightowlers
- Wellcome Centre for Mitochondrial Research, Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle Upon Tyne NE2 4HH, UK
| | - Emma Wakeling
- North East Thames Regional Genetic Service, Great Ormond Street Hospital NHS Foundation Trust, London, UK
| | - Robert W Taylor
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle Upon Tyne NE2 4HH, UK; NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle Upon Tyne NE1 4LP, UK.
| | - Bernhard Kuhle
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA; Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen 37073, Germany.
| |
Collapse
|
3
|
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.
Collapse
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.
| |
Collapse
|
4
|
Fink JK. The hereditary spastic paraplegias. HANDBOOK OF CLINICAL NEUROLOGY 2023; 196:59-88. [PMID: 37620092 DOI: 10.1016/b978-0-323-98817-9.00022-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/26/2023]
Abstract
The hereditary spastic paraplegias (HSPs) are a group of more than 90 genetic disorders in which lower extremity spasticity and weakness are either the primary neurologic impairments ("uncomplicated HSP") or when accompanied by other neurologic deficits ("complicated HSP"), important features of the clinical syndrome. Various genetic types of HSP are inherited such as autosomal dominant, autosomal recessive, X-linked, and maternal (mitochondrial) traits. Symptoms that begin in early childhood may be nonprogressive and resemble spastic diplegic cerebral palsy. Symptoms that begin later, typically progress insidiously over a number of years. Genetic testing is able to confirm the diagnosis for many subjects. Insights from gene discovery indicate that abnormalities in diverse molecular processes underlie various forms of HSP, including disturbance in axon transport, endoplasmic reticulum morphogenesis, vesicle transport, lipid metabolism, and mitochondrial function. Pathologic studies in "uncomplicated" HSP have shown axon degeneration particularly involving the distal ends of corticospinal tracts and dorsal column fibers. Treatment is limited to symptom reduction including amelioration of spasticity, reducing urinary urgency, proactive physical therapy including strengthening, stretching, balance, and agility exercise.
Collapse
Affiliation(s)
- John K Fink
- Department of Neurology, University of Michigan, Ann Arbor, MI, United States.
| |
Collapse
|
5
|
Panzeri E, Citterio A, Martinuzzi A, Ancona V, Martini E, Bassi MT. Case report: A novel FARS2 deletion and a missense variant in a child with complicated, rapidly progressive spastic paraplegia. Front Genet 2023; 14:1130687. [PMID: 37152989 PMCID: PMC10154595 DOI: 10.3389/fgene.2023.1130687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 03/23/2023] [Indexed: 05/09/2023] Open
Abstract
Defects in FARS2 are associated with either epileptic phenotypes or a spastic paraplegia subtype known as SPG77. Here, we describe an 8-year-old patient with severe and complicated spastic paraplegia, carrying a missense variant (p.Pro361Leu) and a novel intragenic deletion in FARS2. Of note, the disease is unexpectedly progressing rapidly and in a biphasic way differently from the previously reported cases. Our study provides the first detailed molecular characterization of a FARS2 deletion and its underlying molecular mechanism, and demonstrates the need for combining different tools to improve the diagnostic rate.
Collapse
Affiliation(s)
- Elena Panzeri
- Laboratory of Molecular Biology, Scientific Institute IRCCS E. Medea, Bosisio Parini, Italy
- *Correspondence: Elena Panzeri,
| | - Andrea Citterio
- Laboratory of Molecular Biology, Scientific Institute IRCCS E. Medea, Bosisio Parini, Italy
| | - Andrea Martinuzzi
- Department of Neurorehabilitation, Scientific Institute IRCCS E. Medea, Conegliano, Italy
| | - Vera Ancona
- Department of Neurorehabilitation, Scientific Institute IRCCS E. Medea, Conegliano, Italy
| | - Eleonora Martini
- Department of Neurorehabilitation, Scientific Institute IRCCS E. Medea, Conegliano, Italy
| | - Maria Teresa Bassi
- Laboratory of Molecular Biology, Scientific Institute IRCCS E. Medea, Bosisio Parini, Italy
| |
Collapse
|
6
|
Li L, Ma J, Wang J, Dong L, Liu S. Two Chinese siblings of combined oxidative phosphorylation deficiency 14 caused by compound heterozygous variants in FARS2. Eur J Med Res 2022; 27:184. [PMID: 36155627 PMCID: PMC9511728 DOI: 10.1186/s40001-022-00808-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Accepted: 09/01/2022] [Indexed: 11/10/2022] Open
Abstract
Background As a rare mitochondrial disease, combined oxidative phosphorylation deficiency 14 (COXPD14) is caused by biallelic variants in the phenylalanyl-tRNA synthetase 2, mitochondrial gene (FARS2) with clinical features of developmental delay, an elevated lactate level, early-onset encephalopathy, liver failure, and hypotonia. The objectives of this study were to analyze the clinical and molecular features of two Chinese siblings affected with COXPD14, and to review relevant literature. Methods Mutation screening was performed by whole exome sequencing (WES) in combination with Sanger sequencing validation to identify the disease-causing variants of the two patients. Results The two siblings presented with severe clinical features and both progressed aggressively and failed to survive after treatment abandonment. We identified two compound heterozygous FARS2 variants c.925G>A p.Gly309Ser and c.943G>C p.Gly315Arg in this proband, which were inherited from the unaffected father and mother, respectively. In addition, Sanger sequencing confirmed that the elder affected sister carried the same compound heterozygous variants. The c.925G>A p.Gly309Ser variant is known and commonly reported in COXPD14 patients, while c.943G>C p.Gly315Arg is a novel one. Neither of the variants was found in 100 Chinese healthy controls. Both variants were classified as “deleterious” and were located in the highly conserved regions of the protein. The above results suggested that the two variants were likely causative in this COXPD14-affected pedigree. Conclusions Our study expands the mutation spectrum of FARS2 and highlights the importance of genetic testing in the diagnosis of diseases with a wide variety of phenotypes, especially in the differential diagnosis of diseases.
Collapse
Affiliation(s)
- Liangshan Li
- Medical Genetic Department, The Affiliated Hospital of Qingdao University, Qingdao, 266003, China
| | - Jianhua Ma
- Department of Reproductive Medicine, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Jingli Wang
- Medical Genetic Department, The Affiliated Hospital of Qingdao University, Qingdao, 266003, China
| | - Liping Dong
- Neonatal Disease Screening Center, Zibo Maternal and Child Health Hospital, Zibo, 255000, China.
| | - Shiguo Liu
- Medical Genetic Department, The Affiliated Hospital of Qingdao University, Qingdao, 266003, China.
| |
Collapse
|
7
|
Chen X, Liu F, Li B, Wang Y, Yuan L, Yin A, Chen Q, Hu W, Yao Y, Zhang M, Wu Y, Chen K. Neuropathy-associated Fars2 deficiency affects neuronal development and potentiates neuronal apoptosis by impairing mitochondrial function. Cell Biosci 2022; 12:103. [PMID: 35794642 PMCID: PMC9258231 DOI: 10.1186/s13578-022-00838-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Accepted: 06/23/2022] [Indexed: 11/22/2022] Open
Abstract
Background Neurodegenerative diseases encompass an extensive and heterogeneous group of nervous system disorders which are characterized by progressive degeneration and death of neurons. Many lines of evidence suggest the participation of mitochondria dysfunction in these diseases. Mitochondrial phenylalanyl-tRNA synthetase, encoded by FARS2, catalyzes the transfer of phenylalanine to its cognate tRNA for protein synthesis. As a member of mt-aaRSs genes, FARS2 missense homozygous mutation c.424G > T (p.D142Y) found in a Chinese consanguineous family first built the relationship between pure hereditary spastic paraplegia (HSP) and FARS2 gene. More FARS2 variations were subsequently found to cause heterogeneous group of neurologic disorders presenting three main phenotypic manifestations: infantile-onset epileptic mitochondrial encephalopathy, later-onset spastic paraplegia and juvenile onset refractory epilepsy. Studies showed that aminoacylation activity is frequently disrupt in cases with FARS2 mutations, indicating a loss-of-function mechanism. However, the underlying pathogenesis of neuropathy-associated Fars2 deficiency is still largely unknown. Results Early gestation lethality of global Fars2 knockout mice was observed prior to neurogenesis. The conditional Fars2 knockout-mouse model delayed lethality to late-gestation, resulting in a thinner cortex and an enlarged ventricle which is consist with the MRI results revealing cortical atrophy and reduced cerebral white matter volume in FARS2-deficient patients. Delayed development of neurite outgrowth followed by neuronal apoptosis was confirmed in Fars2-knockdown mouse primary cultured neurons. Zebrafish, in which fars2 was knocked down, exhibited aberrant motor neuron function including reduced locomotor capacity which well restored the spastic paraplegia phenotype of FARS2-deficient patients. Altered mitochondrial protein synthesis and reduced levels of oxidative phosphorylation complexes were detected in Fars2-deficient samples. And thus, reduced ATP, total NAD levels and mitochondrial membrane potential, together with increased ROS production, revealed mitochondrial dysfunction both in vitro and in vivo. Dctn3 is a potential downstream molecule in responds to Fars2 deficient in neurons, which may provide some evidence for the development of pathogenesis study and therapeutic schedule. Conclusions The Fars2 deficiency genetic models developed in this study cover the typical clinical manifestations in FARS2 patients, and help clarify how neuropathy-associated Fars2 deficiency, by damaging the mitochondrial respiratory chain and impairing mitochondrial function, affects neuronal development and potentiates neuronal cell apoptosis. Supplementary Information The online version contains supplementary material available at 10.1186/s13578-022-00838-y.
Collapse
Affiliation(s)
- Xihui Chen
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China.,Shaanxi Provincial Key Laboratory of Clinic Genetics, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China
| | - Fangfang Liu
- Department of Neurobiology, School of Basic Medicine, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China
| | - Bowen Li
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China.,Shaanxi Provincial Key Laboratory of Clinic Genetics, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China
| | - Yufeng Wang
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China.,Shaanxi Provincial Key Laboratory of Clinic Genetics, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China.,Medical Genetics, Yan'an University, Yan'an, Shaanxi, People's Republic of China
| | - Lijuan Yuan
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China.,Shaanxi Provincial Key Laboratory of Clinic Genetics, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China.,Department of General Surgery, Tangdu Hospital, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China
| | - Anan Yin
- Department of Neurosurgery, Xijing Institute of Clinical Neuroscience, Department of Plastic surgery, Xijing Hospital, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China
| | - Qi Chen
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China.,Shaanxi Provincial Key Laboratory of Clinic Genetics, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China
| | - Weihong Hu
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China.,Shaanxi Provincial Key Laboratory of Clinic Genetics, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China.,Medical Genetics, Yan'an University, Yan'an, Shaanxi, People's Republic of China
| | - Yan Yao
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China.,Shaanxi Provincial Key Laboratory of Clinic Genetics, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China.,Medical Genetics, Yan'an University, Yan'an, Shaanxi, People's Republic of China
| | - Mengjie Zhang
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China.,Shaanxi Provincial Key Laboratory of Clinic Genetics, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China.,Medical Genetics, Yan'an University, Yan'an, Shaanxi, People's Republic of China
| | - YuanMing Wu
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China. .,Shaanxi Provincial Key Laboratory of Clinic Genetics, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China.
| | - Kun Chen
- Department of Anatomy, Histology and Embryology and K.K. Leung Brain Research Centre, School of Basic Medicine, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China.
| |
Collapse
|
8
|
Li B, Chen K, Liu F, Zhang J, Chen X, Chen T, Chen Q, Yao Y, Hu W, Wang L, Wu Y. Developmental Angiogenesis Requires the Mitochondrial Phenylalanyl-tRNA Synthetase. Front Cardiovasc Med 2021; 8:724846. [PMID: 34540921 PMCID: PMC8440837 DOI: 10.3389/fcvm.2021.724846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 08/04/2021] [Indexed: 12/03/2022] Open
Abstract
Background: Mitochondrial aminoacyl-tRNA synthetases (mtARSs) catalyze the binding of specific amino acids to their cognate tRNAs and play an essential role in the synthesis of proteins encoded by mitochondrial DNA. Defects in mtARSs have been linked to human diseases, but their tissue-specific pathophysiology remains elusive. Here we examined the role of mitochondrial phenylalanyl-tRNA synthetase (FARS2) in developmental angiogenesis and its potential contribution to the pathogenesis of cardiovascular disease. Methods: Morpholinos were injected into fertilized zebrafish ova to establish an in vivo fars2 knock-down model. A visualization of the vasculature was achieved by using Tg (fli1: EGFP)y1 transgenic zebrafish. In addition, small interference RNAs (siRNAs) were transferred into human umbilical vein endothelial cells (HUVECs) to establish an in vitro FARS2 knock-down model. Cell motility, proliferation, and tubulogenesis were determined using scratch-wound CCK8, transwell-based migration, and tube formation assays. In addition, mitochondria- and non-mitochondria-related respiration were evaluated using a Seahorse XF24 analyzer and flow cytometry assays. Analyses of the expression levels of transcripts and proteins were performed using qRT-PCR and western blotting, respectively. Results: The knock-down of fars2 hampered the embryonic development in zebrafish and delayed the formation of the vasculature in Tg (fli1: EGFP)y1 transgenic zebrafish. In addition, the siRNA-mediated knock-down of FARS2 impaired angiogenesis in HUVECs as indicated by decreased cell motility and tube formation capacity. The knock-down of FARS2 also produced variable decreases in mitochondrial- and non-mitochondrial respiration in HUVECs and disrupted the regulatory pathways of angiogenesis in both HUVECs and zebrafish. Conclusion: Our current work offers novel insights into angiogenesis defects and cardiovascular diseases induced by FARS2 deficiency.
Collapse
Affiliation(s)
- Bowen Li
- Department of Biochemistry and Molecular Biology, Air Force Medical University, Xi'an, China.,Shaanxi Provincial Key Laboratory of Clinic Genetics, Air Force Medical University, Xi'an, China
| | - Kun Chen
- Department of Anatomy, Histology and Embryology and K.K. Leung Brain Research Centre, Air Force Medical University, Xi'an, China
| | - Fangfang Liu
- Department of Neurosciences, Air Force Medical University, Xi'an, China
| | - Juan Zhang
- Department of Biochemistry and Molecular Biology, College of Life Sciences, Northwest University, Xi'an, China
| | - Xihui Chen
- Department of Biochemistry and Molecular Biology, Air Force Medical University, Xi'an, China.,Shaanxi Provincial Key Laboratory of Clinic Genetics, Air Force Medical University, Xi'an, China
| | - Tangdong Chen
- Department of Biochemistry and Molecular Biology, Air Force Medical University, Xi'an, China.,Shaanxi Provincial Key Laboratory of Clinic Genetics, Air Force Medical University, Xi'an, China
| | - Qi Chen
- Department of Biochemistry and Molecular Biology, Air Force Medical University, Xi'an, China.,Shaanxi Provincial Key Laboratory of Clinic Genetics, Air Force Medical University, Xi'an, China
| | - Yan Yao
- Department of Clinical Medicine, Yan'an University, Yan'an, China
| | - Weihong Hu
- Department of Clinical Medicine, Yan'an University, Yan'an, China
| | - Li Wang
- Department of Biochemistry and Molecular Biology, Air Force Medical University, Xi'an, China.,Shaanxi Provincial Key Laboratory of Clinic Genetics, Air Force Medical University, Xi'an, China.,School of Aerospace Medicine, Air Force Medical University, Xi'an, China
| | - Yuanming Wu
- Department of Biochemistry and Molecular Biology, Air Force Medical University, Xi'an, China.,Shaanxi Provincial Key Laboratory of Clinic Genetics, Air Force Medical University, Xi'an, China
| |
Collapse
|
9
|
Novel FARS2 variants in patients with early onset encephalopathy with or without epilepsy associated with long survival. Eur J Hum Genet 2020; 29:533-538. [PMID: 33168986 DOI: 10.1038/s41431-020-00757-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 09/10/2020] [Accepted: 10/20/2020] [Indexed: 11/08/2022] Open
Abstract
Mitochondrial translation is essential for the biogenesis of the mitochondrial oxidative phosphorylation system (OXPHOS) that synthesizes the bulk of ATP for the cell. Hypomorphic and loss-of-function variants in either mitochondrial DNA or in nuclear genes that encode mitochondrial translation factors can result in impaired OXPHOS biogenesis and mitochondrial diseases with variable clinical presentations. Compound heterozygous or homozygous missense and frameshift variants in the FARS2 gene, that encodes the mitochondrial phenylalanyl-tRNA synthetase, are commonly linked to either early-onset epileptic mitochondrial encephalopathy or spastic paraplegia. Here, we expand the genetic spectrum of FARS2-linked disease with three patients carrying novel compound heterozygous variants in the FARS2 gene and presenting with spastic tetraparesis, axial hypotonia and myoclonic epilepsy in two cases.
Collapse
|
10
|
Hotait M, Nasreddine W, El-Khoury R, Dirani M, Nawfal O, Beydoun A. FARS2 Mutations: More Than Two Phenotypes? A Case Report. Front Genet 2020; 11:787. [PMID: 32774346 PMCID: PMC7387725 DOI: 10.3389/fgene.2020.00787] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 07/02/2020] [Indexed: 12/04/2022] Open
Abstract
FARS2, a nuclear gene, encodes the mitochondrial phenylalanyl-tRNA synthetase (mtPheRS). Previous reports have described two distinct phenotypes linked to FARS2 gene mutation: an early onset epileptic encephalopathy and spastic paraplegia. This report describes a distinctive phenotype of FARS2-linked, juvenile onset refractory epilepsy, caused by a hemizygous mutation in a compound heterozygous state (p.V197M and exon 2 microdeletion). A 17-year- old woman with normal development presented with a super refractory focal motor status epilepticus. Only an emergency life-saving surgery aborted her status after all therapeutic interventions, including anesthesia, failed to control her seizures. Pathological and biochemical activities on muscle biopsy showed mitochondrial proliferation with enhanced isolated activities of complexes II and IV, suggestive of a compensatory mechanism for the bioenergetic deficiency. Postoperatively, the patient started experiencing focal aware motor seizures originating from the contralateral hemisphere after being seizure free for a few months. This report suggests a third phenotypic manifestation of FARS2 gene mutation.
Collapse
Affiliation(s)
- Mostafa Hotait
- Department of Neurology, American University of Beirut Medical Center, Beirut, Lebanon
| | - Wassim Nasreddine
- Department of Neurology, American University of Beirut Medical Center, Beirut, Lebanon
| | - Riyad El-Khoury
- Department of Pathology and Laboratory Medicine, American University of Beirut Medical Center, Beirut, Lebanon
| | - Maya Dirani
- Department of Neurology, American University of Beirut Medical Center, Beirut, Lebanon
| | - Omar Nawfal
- Department of Neurology, American University of Beirut Medical Center, Beirut, Lebanon
| | - Ahmad Beydoun
- Department of Neurology, American University of Beirut Medical Center, Beirut, Lebanon
| |
Collapse
|
11
|
Peretz M, Tworowski D, Kartvelishvili E, Livingston J, Chrzanowska-Lightowlers Z, Safro M. Breaking a single hydrogen bond in the mitochondrial tRNA Phe -PheRS complex leads to phenotypic pleiotropy of human disease. FEBS J 2020; 287:3814-3826. [PMID: 32115907 PMCID: PMC7540514 DOI: 10.1111/febs.15268] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 01/09/2020] [Accepted: 02/27/2020] [Indexed: 01/19/2023]
Abstract
Various pathogenic variants in both mitochondrial tRNAPhe and Phenylalanyl‐tRNA synthetase mitochondrial protein coding gene (FARS2) gene encoding for the human mitochondrial PheRS have been identified and associated with neurological and/or muscle‐related pathologies. An important Guanine‐34 (G34)A anticodon mutation associated with myoclonic epilepsy with ragged red fibers (MERRF) syndrome has been reported in hmit‐tRNAPhe. The majority of G34 contacts in available aaRSs‐tRNAs complexes specifically use that base as an important tRNA identity element. The network of intermolecular interactions providing its specific recognition also largely conserved. However, their conservation depends also on the invariance of the residues in the anticodon binding domain (ABD) of human mitochondrial Phenylalanyl‐tRNA synthetase (hmit‐PheRS). A defect in recognition of the anticodon of tRNAPhe may happen not only because of G34A mutation, but also due to mutations in the ABD. Indeed, a pathogenic mutation in FARS2 has been recently reported in a 9‐year‐old female patient harboring a p.Asp364Gly mutation. Asp364 is hydrogen bonded (HB) to G34 in WT hmit‐PheRS. Thus, there are two pathogenic variants disrupting HB between G34 and Asp364: one is associated with G34A mutation, and the other with Asp364Gly mutation. We have measured the rates of tRNAPhe aminoacylation catalyzed by WT hmit‐PheRS and mutant enzymes. These data ranked the residues making a HB with G34 according to their contribution to activity and the signal transduction pathway in the hmit‐PheRS‐tRNAPhe complex. Furthermore, we carried out extensive MD simulations to reveal the interdomain contact topology on the dynamic trajectories of the complex, and gaining insight into the structural and dynamic integrity effects of hmit‐PheRS complexed with tRNAPhe. Database Structural data are available in PDB database under the accession number(s): 3CMQ, 3TUP, 5MGH, 5MGV.
Collapse
Affiliation(s)
- Moshe Peretz
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Dmitry Tworowski
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | | | | | | | - Mark Safro
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| |
Collapse
|
12
|
Meszarosova AU, Seeman P, Jencik J, Drabova J, Cibochova R, Stellmachova J, Safka Brozkova D. Two types of recessive hereditary spastic paraplegia in Roma patients in compound heterozygous state; no ethnically prevalent variant found. Neurosci Lett 2020; 721:134800. [PMID: 32007496 DOI: 10.1016/j.neulet.2020.134800] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 01/09/2020] [Accepted: 01/29/2020] [Indexed: 10/25/2022]
Abstract
Hereditary spastic paraplegia (HSP or SPG) is a group of rare upper motor neuron diseases. As some ethnically-specific, disease-causing homozygous variants were described in the Czech Roma population, we hypotesised that some prevalent HSP-causing variant could exist in this population. Eight Czech Roma patients were found in a large group of Czech patients with suspected HSP and were tested using gene panel massively parallel sequencing (MPS). Two of the eight were diagnosed with SPG11 and SPG77, respectively. The SPG77 patient manifests a pure HSP phenotype, which is unusual for this SPG type. Both patients are compound heterozygotes for two different variants in the SPG11 (c.1603-1G>A and del ex. 16-18) and FARS2 (c.1082C>T and del ex.1-2) genes respectively; the three variants are novel. In order to find a potential ethnically-specific, disease-causing variant for HSP, we tested the heterozygote frequency of these variants among 130 anonymised DNA samples of Czech Roma individuals without clinical signs of HSP (HPS-negative). A novel deletion of ex.16-18 in the SPG11 gene was found in a heterozygous state in one individual in the HSP-negative group. Haplotype analysis showed that this individual and the patient with SPG11 shared the same haplotype. This supports the assumption that the identified SPG11 deletion could be a founder mutation in the Czech Roma population. In some Roma patients the disease may also be caused by two different biallelic pathogenic mutations.
Collapse
Affiliation(s)
- Anna Uhrova Meszarosova
- DNA Laboratory, Department of Paediatric Neurology, 2nd Faculty of Medicine Charles University and University Hospital Motol, Prague, Czech Republic.
| | - Pavel Seeman
- DNA Laboratory, Department of Paediatric Neurology, 2nd Faculty of Medicine Charles University and University Hospital Motol, Prague, Czech Republic
| | - Jan Jencik
- DNA Laboratory, Department of Paediatric Neurology, 2nd Faculty of Medicine Charles University and University Hospital Motol, Prague, Czech Republic
| | - Jana Drabova
- Department of Biology and Medical Genetics, 2nd Faculty of Medicine Charles University and University Hospital Motol, Prague, Czech Republic
| | - Renata Cibochova
- Department of Paediatric Neurology, 2nd Faculty of Medicine Charles University and University Hospital Motol, Prague, Czech Republic
| | - Julia Stellmachova
- Department of Medical Genetics, Palacky University Hospital, Olomouc, Czech Republic
| | - Dana Safka Brozkova
- DNA Laboratory, Department of Paediatric Neurology, 2nd Faculty of Medicine Charles University and University Hospital Motol, Prague, Czech Republic
| |
Collapse
|
13
|
Sazonova MA, Ryzhkova AI, Sinyov VV, Sazonova MD, Khasanova ZB, Nikitina NA, Karagodin VP, Orekhov AN, Sobenin IA. Creation of Cultures Containing Mutations Linked with Cardiovascular Diseases using Transfection and Genome Editing. Curr Pharm Des 2020; 25:693-699. [PMID: 30931844 DOI: 10.2174/1381612825666190329121532] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 03/25/2019] [Indexed: 12/18/2022]
Abstract
OBJECTIVE In this review article, we analyzed the literature on the creation of cultures containing mutations associated with cardiovascular diseases (CVD) using transfection, transduction and editing of the human genome. METHODS We described different methods of transfection, transduction and editing of the human genome, used in the literature. RESULTS We reviewed the researches in which the creation of сell cultures containing mutations was described. According to the literature, system CRISPR/Cas9 proved to be the most preferred method for editing the genome. We found rather promising and interesting a practically undeveloped direction of mitochondria transfection using a gene gun. Such a gun can direct a genetically-engineered construct containing human DNA mutations to the mitochondria using heavy metal particles. However, in human molecular genetics, the transfection method using a gene gun is unfairly forgotten and is almost never used. Ethical problems arising from editing the human genome were also discussed in our review. We came to a conclusion that it is impossible to stop scientific and technical progress. It is important that the editing of the genome takes place under the strict control of society and does not bear dangerous consequences for humanity. To achieve this, the constant interaction of science with society, culture and business is necessary. CONCLUSION The most promising methods for the creation of cell cultures containing mutations linked with cardiovascular diseases, were system CRISPR/Cas9 and the gene gun.
Collapse
Affiliation(s)
- Margarita A Sazonova
- Laboratory of Medical Genetics, National Medical Research Center of Cardiology, Moscow, Russian Federation.,Laboratory of Angiopathology, Institute of General Pathology and Pathophysiology, Moscow, Russian Federation
| | - Anastasia I Ryzhkova
- Laboratory of Angiopathology, Institute of General Pathology and Pathophysiology, Moscow, Russian Federation
| | - Vasily V Sinyov
- Laboratory of Medical Genetics, National Medical Research Center of Cardiology, Moscow, Russian Federation
| | - Marina D Sazonova
- Laboratory of Angiopathology, Institute of General Pathology and Pathophysiology, Moscow, Russian Federation
| | - Zukhra B Khasanova
- Laboratory of Medical Genetics, National Medical Research Center of Cardiology, Moscow, Russian Federation
| | - Nadezhda A Nikitina
- Laboratory of Medical Genetics, National Medical Research Center of Cardiology, Moscow, Russian Federation
| | | | - Alexander N Orekhov
- Laboratory of Angiopathology, Institute of General Pathology and Pathophysiology, Moscow, Russian Federation
| | - Igor A Sobenin
- Laboratory of Medical Genetics, National Medical Research Center of Cardiology, Moscow, Russian Federation.,Laboratory of Angiopathology, Institute of General Pathology and Pathophysiology, Moscow, Russian Federation
| |
Collapse
|
14
|
Chen Z, Zhang Y. A patient with juvenile-onset refractory status epilepticus caused by two novel compound heterozygous mutations in FARS2 gene. Int J Neurosci 2019; 129:1094-1097. [PMID: 31329004 DOI: 10.1080/00207454.2019.1634071] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
FARS2 encodes mitochondrial phenylalanyl transfer ribonucleic acid (RNA) synthetase and is implicated in autosomal recessive combined oxidative phosphorylation deficiency 14. The clinical manifestation can be divided into early onset epileptic phenotype and spastic paraplegia phenotype. The purpose of this study was to report a case of juvenile manifesting refractory epilepsy caused by two novel compound heterozygous mutations in the FARS2 gene. Microscopic and histochemical examination as well as next-generation sequencing and reconstruction of the three-dimensional structure of FARS2 protein were performed. A 17-year-old man with no developmental delays suffered from generalized tonic-clonic convulsion since 12 years of age and developed refractory status epilepticus 5 years later. No specific etiology was found following brain imaging, muscle biopsy and metabolic studies. DNA sequencing identified two novel compound heterozygous mutations in FARS2, (p.V197M and p.F402S), derived from each parents, respectively. These mutations affected the structure or thermodynamic stability of the protein. This is a case report of juvenile-onset refractory epilepsy caused by two novel compound heterozygous mutations in the FARS2 gene. This case confirms and expands the clinicalphenotype and the genotypic spectrum of the FARS2 gene.
Collapse
Affiliation(s)
- Zhongyun Chen
- Department of Neurology, Xuanwu Hospital, Capital Medical University , Beijing , China
| | - Yan Zhang
- Department of Neurology, Xuanwu Hospital, Capital Medical University , Beijing , China
| |
Collapse
|
15
|
Complexity of Generating Mouse Models to Study the Upper Motor Neurons: Let Us Shift Focus from Mice to Neurons. Int J Mol Sci 2019; 20:ijms20163848. [PMID: 31394733 PMCID: PMC6720674 DOI: 10.3390/ijms20163848] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 07/26/2019] [Accepted: 08/05/2019] [Indexed: 12/11/2022] Open
Abstract
Motor neuron circuitry is one of the most elaborate circuitries in our body, which ensures voluntary and skilled movement that requires cognitive input. Therefore, both the cortex and the spinal cord are involved. The cortex has special importance for motor neuron diseases, in which initiation and modulation of voluntary movement is affected. Amyotrophic lateral sclerosis (ALS) is defined by the progressive degeneration of both the upper and lower motor neurons, whereas hereditary spastic paraplegia (HSP) and primary lateral sclerosis (PLS) are characterized mainly by the loss of upper motor neurons. In an effort to reveal the cellular and molecular basis of neuronal degeneration, numerous model systems are generated, and mouse models are no exception. However, there are many different levels of complexities that need to be considered when developing mouse models. Here, we focus our attention to the upper motor neurons, which are one of the most challenging neuron populations to study. Since mice and human differ greatly at a species level, but the cells/neurons in mice and human share many common aspects of cell biology, we offer a solution by focusing our attention to the affected neurons to reveal the complexities of diseases at a cellular level and to improve translational efforts.
Collapse
|
16
|
Chakraborty S, Ibba M, Banerjee R. Biophysical characterization Of Alpers encephalopathy associated mutants of human mitochondrial phenylalanyl-tRNA synthetase. IUBMB Life 2019; 71:1141-1149. [PMID: 31241862 DOI: 10.1002/iub.2114] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 06/06/2019] [Indexed: 12/13/2022]
Abstract
Mutations in nucleus-encoded mitochondrial aminoacyl-tRNA synthetases (mitaaRSs) lead to defects in mitochondrial translation affecting the expression and function of 13 subunits of the respiratory chain complex leading to diverse pathological conditions. Mutations in the FARS2 gene encoding human mitochondrial phenylalanyl-tRNA synthetase (HsmitPheRS) have been found to be associated with two different clinical representations, infantile Alpers encephalopathy and spastic paraplegia. Here we have studied three pathogenic mutants (Tyr144Cys, Ile329Thr, and Asp391Val) associated with Alpers encephalopathy to understand how these variants affect the biophysical properties of the enzyme. These mutants have already been reported to have reduced aminoacylation activity. Our study established that the mutants are significantly more thermolabile compared to the wild-type enzyme with reduced solubility in vitro. The presence of aggregation-prone insoluble HsmitPheRS variants could have a detrimental impact on organellar translation, and potentially impact normal mitochondrial function. © 2019 IUBMB Life, 71(8): 1141-1149, 2019 © 2019 IUBMB Life, 71(8):1141-1149, 2019.
Collapse
Affiliation(s)
- Shruti Chakraborty
- Department of Biotechnology and Dr. B. C. Guha Centre for Genetic Engineering and Biotechnology, University of Calcutta, Kolkata, India
| | - Michael Ibba
- Department of Microbiology, The Ohio State University, Columbus, Ohio
| | - Rajat Banerjee
- Department of Biotechnology and Dr. B. C. Guha Centre for Genetic Engineering and Biotechnology, University of Calcutta, Kolkata, India
| |
Collapse
|
17
|
Schaffer AE, Pinkard O, Coller JM. tRNA Metabolism and Neurodevelopmental Disorders. Annu Rev Genomics Hum Genet 2019; 20:359-387. [PMID: 31082281 DOI: 10.1146/annurev-genom-083118-015334] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
tRNAs are short noncoding RNAs required for protein translation. The human genome includes more than 600 putative tRNA genes, many of which are considered redundant. tRNA transcripts are subject to tightly controlled, multistep maturation processes that lead to the removal of flanking sequences and the addition of nontemplated nucleotides. Furthermore, tRNAs are highly structured and posttranscriptionally modified. Together, these unique features have impeded the adoption of modern genomics and transcriptomics technologies for tRNA studies. Nevertheless, it has become apparent from human neurogenetic research that many tRNA biogenesis proteins cause brain abnormalities and other neurological disorders when mutated. The cerebral cortex, cerebellum, and peripheral nervous system show defects, impairment, and degeneration upon tRNA misregulation, suggesting that they are particularly sensitive to changes in tRNA expression or function. An integrated approach to identify tRNA species and contextually characterize tRNA function will be imperative to drive future tool development and novel therapeutic design for tRNA-associated disorders.
Collapse
Affiliation(s)
- Ashleigh E Schaffer
- Department of Genetics and Genome Sciences and Center for RNA Science and Therapeutics, Case Western Reserve University, Cleveland, Ohio 44106, USA;
| | - Otis Pinkard
- Department of Genetics and Genome Sciences and Center for RNA Science and Therapeutics, Case Western Reserve University, Cleveland, Ohio 44106, USA;
| | - Jeffery M Coller
- Department of Genetics and Genome Sciences and Center for RNA Science and Therapeutics, Case Western Reserve University, Cleveland, Ohio 44106, USA;
| |
Collapse
|
18
|
Almannai M, Wang J, Dai H, El-Hattab AW, Faqeih EA, Saleh MA, Al Asmari A, Alwadei AH, Aljadhai YI, AlHashem A, Tabarki B, Lines MA, Grange DK, Benini R, Alsaman AS, Mahmoud A, Katsonis P, Lichtarge O, Wong LJC. FARS2 deficiency; new cases, review of clinical, biochemical, and molecular spectra, and variants interpretation based on structural, functional, and evolutionary significance. Mol Genet Metab 2018; 125:281-291. [PMID: 30177229 DOI: 10.1016/j.ymgme.2018.07.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 07/25/2018] [Accepted: 07/25/2018] [Indexed: 02/07/2023]
Abstract
An increasing number of mitochondrial diseases are found to be caused by pathogenic variants in nuclear encoded mitochondrial aminoacyl-tRNA synthetases. FARS2 encodes mitochondrial phenylalanyl-tRNA synthetase (mtPheRS) which transfers phenylalanine to its cognate tRNA in mitochondria. Since the first case was reported in 2012, a total of 21 subjects with FARS2 deficiency have been reported to date with a spectrum of disease severity that falls between two phenotypes; early onset epileptic encephalopathy and a less severe phenotype characterized by spastic paraplegia. In this report, we present an additional 15 individuals from 12 families who are mostly Arabs homozygous for the pathogenic variant Y144C, which is associated with the more severe early onset phenotype. The total number of unique pathogenic FARS2 variants known to date is 21 including three different partial gene deletions reported in four individuals. Except for the large deletions, all variants but two (one in-frame deletion of one amino acid and one splice-site variant) are missense. All large deletions and the single splice-site variant are in trans with a missense variant. This suggests that complete loss of function may be incompatible with life. In this report, we also review structural, functional, and evolutionary significance of select FARS2 pathogenic variants reported here.
Collapse
Affiliation(s)
- Mohammed Almannai
- Section of Medical Genetics, Children's Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Julia Wang
- Medical Scientist Training Program and Program in Developmental Biology, Baylor College of Medicine, Houston, TX, USA
| | - Hongzheng Dai
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Ayman W El-Hattab
- Division of Clinical Genetics and Metabolic Disorders, Pediatric Department, Tawam Hospital, Al-Ain, United Arab Emirates
| | - Eissa A Faqeih
- Section of Medical Genetics, Children's Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Mohammed A Saleh
- Section of Medical Genetics, Children's Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Ali Al Asmari
- Section of Medical Genetics, Children's Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Ali H Alwadei
- Department of Pediatric Neurology, National Neuroscience Institute, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Yaser I Aljadhai
- Department of Neuroimaging and Intervention, Medical Imaging Administration, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Amal AlHashem
- Department of Pediatric, Prince Sultan Medical Military City, Riyadh, Saudi Arabia; Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Brahim Tabarki
- Divisions of Pediatric Neurology, Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Matthew A Lines
- Division of Metabolics and Newborn Screening, Children's Hospital of Eastern Ontario, Department of Pediatrics, Faculty of Medicine, University of Ottawa, Ottawa, Canada
| | - Dorothy K Grange
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, USA
| | - Ruba Benini
- Department of Pediatric Neurology, National Neuroscience Institute, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Abdulaziz S Alsaman
- Department of Pediatric Neurology, National Neuroscience Institute, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Adel Mahmoud
- Department of Pediatric Neurology, National Neuroscience Institute, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Panagiotis Katsonis
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Olivier Lichtarge
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Lee-Jun C Wong
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
| |
Collapse
|
19
|
Sahai SK, Steiner RE, Au MG, Graham JM, Salamon N, Ibba M, Pierson TM. FARS2 mutations presenting with pure spastic paraplegia and lesions of the dentate nuclei. Ann Clin Transl Neurol 2018; 5:1128-1133. [PMID: 30250868 PMCID: PMC6144452 DOI: 10.1002/acn3.598] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 05/26/2018] [Accepted: 05/29/2018] [Indexed: 01/14/2023] Open
Abstract
Mutations in FARS2, the gene encoding the mitochondrial phenylalanine‐tRNA synthetase (mtPheRS), have been linked to a range of phenotypes including epileptic encephalopathy, developmental delay, and motor dysfunction. We report a 9‐year‐old boy with novel compound heterozygous variants of FARS2, presenting with a pure spastic paraplegia syndrome associated with bilateral signal abnormalities in the dentate nuclei. Exome sequencing identified a paternal nonsense variant (Q216X) lacking the catalytic core and anticodon‐binding regions, and a maternal missense variant (P136H) possessing partial enzymatic activity. This case confirms and expands the phenotype related to FARS2 mutations with regards to clinical presentation and neuroimaging findings.
Collapse
Affiliation(s)
- Supreet K Sahai
- Department of Neurology Cedars-Sinai Medical Center Los Angeles California
| | - Rebecca E Steiner
- Department of Microbiology Ohio State University Columbus Ohio 43210.,Center for RNA Biology Ohio State University Columbus Ohio 43210.,Ohio State Biochemistry Program Ohio State University Columbus Ohio 43210
| | - Margaret G Au
- Department of Pediatrics Cedars-Sinai Medical Center Los Angeles California
| | - John M Graham
- Department of Pediatrics Cedars-Sinai Medical Center Los Angeles California
| | - Noriko Salamon
- Department of Radiological Sciences David Geffen School of Medicine University of California Los Angeles Los Angeles California
| | - Michael Ibba
- Department of Microbiology Ohio State University Columbus Ohio 43210.,Center for RNA Biology Ohio State University Columbus Ohio 43210.,Ohio State Biochemistry Program Ohio State University Columbus Ohio 43210
| | - Tyler M Pierson
- Department of Neurology Cedars-Sinai Medical Center Los Angeles California.,Department of Pediatrics Cedars-Sinai Medical Center Los Angeles California.,Board of Governors Regenerative Medicine Institute Cedars-Sinai Medical Center Los Angeles California
| |
Collapse
|
20
|
Peycheva V, Kamenarova K, Ivanova N, Stamatov D, Avdjieva-Tzavella D, Alexandrova I, Zhelyazkova S, Pacheva I, Dimova P, Ivanov I, Litvinenko I, Bozhinova V, Tournev I, Simeonov E, Mitev V, Jordanova A, Kaneva R. Chromosomal microarray analysis of Bulgarian patients with epilepsy and intellectual disability. Gene 2018; 667:45-55. [DOI: 10.1016/j.gene.2018.05.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 04/13/2018] [Accepted: 05/03/2018] [Indexed: 12/08/2022]
|
21
|
Antonellis A, Oprescu SN, Griffin LB, Heider A, Amalfitano A, Innis JW. Compound heterozygosity for loss-of-function FARSB variants in a patient with classic features of recessive aminoacyl-tRNA synthetase-related disease. Hum Mutat 2018; 39:834-840. [PMID: 29573043 DOI: 10.1002/humu.23424] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 02/17/2018] [Accepted: 03/10/2018] [Indexed: 12/21/2022]
Abstract
Aminoacyl-tRNA synthetases (ARSs) are ubiquitously expressed enzymes that ligate amino acids onto tRNA molecules. Genes encoding ARSs have been implicated in phenotypically diverse dominant and recessive human diseases. The charging of tRNAPHE with phenylalanine is performed by a tetrameric enzyme that contains two alpha (FARSA) and two beta (FARSB) subunits. To date, mutations in the genes encoding these subunits (FARSA and FARSB) have not been implicated in any human disease. Here, we describe a patient with a severe, lethal, multisystem, developmental phenotype who was compound heterozygous for FARSB variants: p.Thr256Met and p.His496Lysfs*14. Expression studies using fibroblasts isolated from the proband revealed a severe depletion of both FARSB and FARSA protein levels. These data indicate that the FARSB variants destabilize total phenylalanyl-tRNA synthetase levels, thus causing a loss-of-function effect. Importantly, our patient shows strong phenotypic overlap with patients that have recessive diseases associated with other ARS loci; these observations strongly support the pathogenicity of the identified FARSB variants and are consistent with the essential function of phenylalanyl-tRNA synthetase in human cells. In sum, our clinical, genetic, and functional analyses revealed the first FARSB variants associated with a human disease phenotype and expand the locus heterogeneity of ARS-related human disease.
Collapse
Affiliation(s)
- Anthony Antonellis
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, Michigan.,Department of Neurology, University of Michigan Medical School, Ann Arbor, Michigan.,Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, Michigan
| | - Stephanie N Oprescu
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, Michigan
| | - Laurie B Griffin
- Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, Michigan.,Medical Scientist Training Program, University of Michigan Medical School, Ann Arbor, Michigan
| | - Amer Heider
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Andrea Amalfitano
- Department of Pediatrics, College of Osteopathic Medicine, Michigan State University, East Lansing, Michigan.,Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan
| | - Jeffrey W Innis
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, Michigan.,Department of Pediatrics, Division of Genetics, Metabolism, and Genomic Medicine, University of Michigan Medical School, Ann Arbor, Michigan
| |
Collapse
|
22
|
Detection of genomic structural variations in Guizhou indigenous pigs and the comparison with other breeds. PLoS One 2018; 13:e0194282. [PMID: 29558483 PMCID: PMC5860705 DOI: 10.1371/journal.pone.0194282] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 02/28/2018] [Indexed: 12/20/2022] Open
Abstract
Genomic structural variation (SV) is noticed for the contribution to genetic diversity and phenotypic changes. Guizhou indigenous pig (GZP) has been raised for hundreds of years with many special characteristics. The present paper aimed to uncover the influence of SV on gene polymorphism and the genetic mechanisms of phenotypic traits for GZP. Eighteen GZPs were chosen for resequencing by Illumina sequencing platform. The confident SVs of GZP were called out by both programs of pindel and softSV simultaneously and compared with the SVs deduced from the genomic data of European pig (EUP) and the native pig outside of Guizhou, China (NPOG). A total of 39,166 SVs were detected and covered 27.37 Mb of pig genome. All of 76 SVs were confirmed in GZP pig population by PCR method. The SVs numbers in NPOG and GZP were about 1.8 to 1.9 times higher than that in EUP. And a SV hotspot was found out from the 20 Mb of chromosome X of GZP, which harbored 29 genes and focused on histone modification. More than half of SVs was positioned in the intergenic regions and about one third of SVs in the introns of genes. And we found that SVs tended to locate in genes produced multi-transcripts, in which a positive correlation was found out between the numbers of SV and the gene transcripts. It illustrated that the primary mode of SVs might function on the regulation of gene expression or the transcripts splicing process. A total of 1,628 protein-coding genes were disturbed by 1,956 SVs specific in GZP, in which 93 GZP-specific SV-related genes would lose their functions due to the SV interference and gathered in reproduction ability. Interestingly, the 1,628 protein-coding genes were mainly enriched in estrogen receptor binding, steroid hormone receptor binding, retinoic acid receptor binding, oxytocin signaling pathway, mTOR signaling pathway, axon guidance and cholinergic synapse pathways. It suggested that SV might be a reason for the strong adaptability and low fecundity of GZP, and 51 candidate genes would be useful for the configuration phenotype in Xiang pig breed.
Collapse
|
23
|
Vantroys E, Larson A, Friederich M, Knight K, Swanson MA, Powell CA, Smet J, Vergult S, De Paepe B, Seneca S, Roeyers H, Menten B, Minczuk M, Vanlander A, Van Hove J, Van Coster R. New insights into the phenotype of FARS2 deficiency. Mol Genet Metab 2017; 122:172-181. [PMID: 29126765 PMCID: PMC5734183 DOI: 10.1016/j.ymgme.2017.10.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 10/09/2017] [Accepted: 10/10/2017] [Indexed: 12/12/2022]
Abstract
Mutations in FARS2 are known to cause dysfunction of mitochondrial translation due to deficient aminoacylation of the mitochondrial phenylalanine tRNA. Here, we report three novel mutations in FARS2 found in two patients in a compound heterozygous state. The missense mutation c.1082C>T (p.Pro361Leu) was detected in both patients. The mutations c.461C>T (p.Ala154Val) and c.521_523delTGG (p.Val174del) were each detected in one patient. We report abnormal in vitro aminoacylation assays as a functional validation of the molecular genetic findings. Based on the phenotypic data of previously reported subjects and the two subjects reported here, we conclude that FARS2 deficiency can be associated with two phenotypes: (i) an epileptic phenotype, and (ii) a spastic paraplegia phenotype.
Collapse
Affiliation(s)
- Elise Vantroys
- Department of Pediatric Neurology and Metabolism, Ghent University Hospital, Ghent, Belgium
| | - Austin Larson
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado School of Medicine, Aurora, CO, USA
| | - Marisa Friederich
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado School of Medicine, Aurora, CO, USA
| | - Kaz Knight
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado School of Medicine, Aurora, CO, USA
| | - Michael A Swanson
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado School of Medicine, Aurora, CO, USA
| | - Christopher A Powell
- MRC Mitochondrial Biology Unit, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
| | - Joél Smet
- Department of Pediatric Neurology and Metabolism, Ghent University Hospital, Ghent, Belgium
| | - Sarah Vergult
- Center for Medical Genetics Ghent, Ghent University, Ghent, Belgium
| | - Boel De Paepe
- Department of Pediatric Neurology and Metabolism, Ghent University Hospital, Ghent, Belgium
| | - Sara Seneca
- Center for Medical Genetics, UZ Brussel and Reproduction Genetics and Regenerative Medicine, Vrije Universiteit Brussel, Brussels, Belgium
| | - Herbert Roeyers
- Department of Experimental Clinical and Health Psychology, Ghent University, Ghent, Belgium
| | - Björn Menten
- Center for Medical Genetics Ghent, Ghent University, Ghent, Belgium
| | - Michal Minczuk
- MRC Mitochondrial Biology Unit, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
| | - Arnaud Vanlander
- Department of Pediatric Neurology and Metabolism, Ghent University Hospital, Ghent, Belgium
| | - Johan Van Hove
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado School of Medicine, Aurora, CO, USA
| | - Rudy Van Coster
- Department of Pediatric Neurology and Metabolism, Ghent University Hospital, Ghent, Belgium.
| |
Collapse
|
24
|
Meyer-Schuman R, Antonellis A. Emerging mechanisms of aminoacyl-tRNA synthetase mutations in recessive and dominant human disease. Hum Mol Genet 2017; 26:R114-R127. [PMID: 28633377 PMCID: PMC5886470 DOI: 10.1093/hmg/ddx231] [Citation(s) in RCA: 112] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 06/09/2017] [Accepted: 06/12/2017] [Indexed: 12/29/2022] Open
Abstract
Aminoacyl-tRNA synthetases (ARSs) are responsible for charging amino acids to cognate tRNA molecules, which is the essential first step of protein translation. Interestingly, mutations in genes encoding ARS enzymes have been implicated in a broad spectrum of human inherited diseases. Bi-allelic mutations in ARSs typically cause severe, early-onset, recessive diseases that affect a wide range of tissues. The vast majority of these mutations show loss-of-function effects and impair protein translation. However, it is not clear how a subset cause tissue-specific phenotypes. In contrast, dominant ARS-mediated diseases specifically affect the peripheral nervous system-most commonly causing axonal peripheral neuropathy-and usually manifest later in life. These neuropathies are linked to heterozygosity for missense mutations in five ARS genes, which points to a shared mechanism of disease. However, it is not clear if a loss-of-function mechanism or a toxic gain-of-function mechanism is responsible for ARS-mediated neuropathy, or if a combination of these mechanisms operate on a mutation-specific basis. Here, we review our current understanding of recessive and dominant ARS-mediated disease. We also propose future directions for defining the molecular mechanisms of ARS mutations toward designing therapies for affected patient populations.
Collapse
Affiliation(s)
- Rebecca Meyer-Schuman
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Anthony Antonellis
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| |
Collapse
|
25
|
Kartvelishvili E, Tworowski D, Vernon H, Moor N, Wang J, Wong LJ, Chrzanowska-Lightowlers Z, Safro M. Kinetic and structural changes in HsmtPheRS, induced by pathogenic mutations in human FARS2. Protein Sci 2017; 26:1505-1516. [PMID: 28419689 PMCID: PMC5521548 DOI: 10.1002/pro.3176] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 04/11/2017] [Accepted: 04/11/2017] [Indexed: 12/13/2022]
Abstract
Mutations in the mitochondrial aminoacyl-tRNA synthetases (mtaaRSs) can cause profound clinical presentations, and have manifested as diseases with very selective tissue specificity. To date most of the mtaaRS mutations could be phenotypically recognized, such that clinicians could identify the affected mtaaRS from the symptoms alone. Among the recently reported pathogenic variants are point mutations in FARS2 gene, encoding the human mitochondrial PheRS. Patient symptoms range from spastic paraplegia to fatal infantile Alpers encephalopathy. How clinical manifestations of these mutations relate to the changes in three-dimensional structures and kinetic characteristics remains unclear, although impaired aminoacylation has been proposed as possible etiology of diseases. Here, we report four crystal structures of HsmtPheRS mutants, and extensive MD simulations for wild-type and nine mutants to reveal the structural changes on dynamic trajectories of HsmtPheRS. Using steady-state kinetic measurements of phenylalanine activation and tRNAPhe aminoacylation, we gained insight into the structural and kinetic effects of mitochondrial disease-related mutations in FARS2 gene.
Collapse
Affiliation(s)
| | - Dmitry Tworowski
- Department of Structural Biology, Weizmann Institute of Science, Israel
| | - Hilary Vernon
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins School of Medicine, Baltimore
| | - Nina Moor
- Laboratory of Bioorganic Chemistry of Enzymes, Institute of Chemical Biology and Fundamental Medicine, Novosibirsk, Russia
| | - Jing Wang
- Ambry Genetics, California.,Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Lee-Jun Wong
- Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | | | - Mark Safro
- Department of Structural Biology, Weizmann Institute of Science, Israel
| |
Collapse
|
26
|
Cho JS, Kim SH, Kim HY, Chung T, Kim D, Jang S, Lee SB, Yoo SK, Shin J, Kim JI, Kim H, Hwang H, Chae JH, Choi J, Kim KJ, Lim BC. FARS2 mutation and epilepsy: Possible link with early-onset epileptic encephalopathy. Epilepsy Res 2017; 129:118-124. [DOI: 10.1016/j.eplepsyres.2016.11.022] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Revised: 11/23/2016] [Accepted: 11/30/2016] [Indexed: 11/26/2022]
|
27
|
Raviglione F, Conte G, Ghezzi D, Parazzini C, Righini A, Vergaro R, Legati A, Spaccini L, Gasperini S, Garavaglia B, Mastrangelo M. Clinical findings in a patient with FARS2 mutations and early-infantile-encephalopathy with epilepsy. Am J Med Genet A 2016; 170:3004-3007. [PMID: 27549011 DOI: 10.1002/ajmg.a.37836] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 06/26/2016] [Indexed: 12/22/2022]
Abstract
The FARS2 gene encodes the mitochondrial phenylalanyl-tRNA synthetase and is implicated in autosomal recessive combined oxidative phosphorylation deficiency 14, a clinical condition characterized by infantile onset epilepsy and encephalopathy. Mutations in FARS2 have been reported in only few patients, but a detailed description of seizures, electroencephalographic patterns, magnetic resonance imaging findings, and long-term follow-up is still needed. We provide a clinical report of a child with FARS2-related disease manifesting drug-resistant infantile spasms associated with focal seizures. By comparative genomic hybridization analysis we identified a heterozygous microdeletion in the short arm of chromosome 6, inherited from the mother, that encompasses the first coding exon of FARS2. By sequencing of the FARS2 gene we identified a variant c.1156C>G; p.(R386G), inherited from the father. By using standard spectrophotometric techniques in skin fibroblasts, we found a combined abnormality of complexes I and IV of the mitochondrial respiratory chain. The main clinical features of the patient included axial hypotonia, mild distal hypertonia, and psychomotor delay. The magnetic resonance imaging showed microcephaly, frontal cerebral atrophy, and signal changes of dentate nuclei. At the age of 3 years and 6 months, the patient was still under treatment with vigabatrin and he has been seizure free for the last 23 months. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
| | - Giorgio Conte
- Postgraduation School in Radiodiagnostics, Università degli Studi di Milano, Milan, Italy.,Department of Paediatric Radiology and Neuroradiology, Children's Hospital V. Buzzi, Milan, Italy
| | - Daniele Ghezzi
- Molecular Neurogenetics Unit, Fondazione IRCCS Istituto Neurologico "Carlo Besta", Milan, Italy
| | - Cecilia Parazzini
- Department of Paediatric Radiology and Neuroradiology, Children's Hospital V. Buzzi, Milan, Italy
| | - Andrea Righini
- Department of Paediatric Radiology and Neuroradiology, Children's Hospital V. Buzzi, Milan, Italy
| | - Raffaella Vergaro
- Paediatric Neurology Unit, Children's Hospital V. Buzzi, Milan, Italy
| | - Andrea Legati
- Molecular Neurogenetics Unit, Fondazione IRCCS Istituto Neurologico "Carlo Besta", Milan, Italy
| | - Luigina Spaccini
- Clinical Genetics Service, Children's Hospital V. Buzzi, Milan, Italy
| | - Serena Gasperini
- Department of Pediatrics, Fondazione MBBM, San Gerardo Hospital, Monza, Italy
| | - Barbara Garavaglia
- Molecular Neurogenetics Unit, Fondazione IRCCS Istituto Neurologico "Carlo Besta", Milan, Italy
| | | |
Collapse
|
28
|
Linnankivi T, Neupane N, Richter U, Isohanni P, Tyynismaa H. Splicing Defect in Mitochondrial Seryl-tRNA Synthetase Gene Causes Progressive Spastic Paresis Instead of HUPRA Syndrome. Hum Mutat 2016; 37:884-8. [PMID: 27279129 DOI: 10.1002/humu.23021] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 05/23/2016] [Indexed: 01/08/2023]
Abstract
Mitochondrial aminoacyl-tRNA synthetases are an important group of disease genes typically underlying either a disorder affecting an isolated tissue or a distinct syndrome. Missense mutations in the mitochondrial seryl-tRNA synthetase gene, SARS2, have been identified in HUPRA syndrome (hyperuricemia, pulmonary hypertension, renal failure in infancy, and alkalosis). We report here a homozygous splicing mutation in SARS2 in a patient with progressive spastic paresis. We show that the mutation leads to diminished levels of the synthetase in patient's fibroblasts. This has a destabilizing effect on the tRNASer(AGY) isoacceptor, but to a lesser degree than in HUPRA syndrome patients. tRNASer(UCN) is largely unaffected in both phenotypes. In conclusion, the level of tRNASer(AGY) instability may be a factor in determining tissue manifestation in patients with SARS2 mutations. This finding exemplifies the sensitivity of the nervous system to partially reduced aminoacylation, which is sufficient in other tissues to maintain respiratory chain function.
Collapse
Affiliation(s)
- Tarja Linnankivi
- Department of Pediatric Neurology, Children's Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Nirajan Neupane
- Research Programs Unit, Molecular Neurology, Biomedicum Helsinki, University of Helsinki, Helsinki, Finland
| | - Uwe Richter
- Research Programs Unit, Molecular Neurology, Biomedicum Helsinki, University of Helsinki, Helsinki, Finland
| | - Pirjo Isohanni
- Department of Pediatric Neurology, Children's Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Research Programs Unit, Molecular Neurology, Biomedicum Helsinki, University of Helsinki, Helsinki, Finland
| | - Henna Tyynismaa
- Research Programs Unit, Molecular Neurology, Biomedicum Helsinki, University of Helsinki, Helsinki, Finland
- Department of Medical and Clinical Genetics, University of Helsinki, Helsinki, Finland
| |
Collapse
|
29
|
Yang Y, Liu W, Fang Z, Shi J, Che F, He C, Yao L, Wang E, Wu Y. A Newly Identified Missense Mutation in FARS2 Causes Autosomal-Recessive Spastic Paraplegia. Hum Mutat 2015; 37:165-9. [PMID: 26553276 DOI: 10.1002/humu.22930] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 11/03/2015] [Indexed: 02/05/2023]
Abstract
Hereditary spastic paraplegia (HSP) is a clinically and genetically heterogeneous group of neurodegenerative disorders characterized by spasticity of the lower limbs due to pyramidal tract dysfunction. Here, we report that a missense homozygous mutation c.424G>T (p.D142Y) in the FARS2 gene, which encodes a mitochondrial phenylalanyl tRNA synthetase (mtPheRS), causes HSP in a Chinese consanguineous family by using combination of homozygous mapping and whole-exome sequencing. Immunohistochemical experiments were performed showing that the FARS2 protein was highly expressed in the Purkinje cells of rat cerebellum. The aminoacylation activity of mtPheRS was severely disrupted by the p.D142Y substitution in vitro not only in the first aminoacylation step but also in the last transfer step. Taken together, our results indicate that a missense mutation in FARS2 contributes to HSP, which has the clinical significance of the regulation of tRNA synthetases in human neurodegenerative diseases.
Collapse
Affiliation(s)
- Ying Yang
- Department of Biochemistry and Molecular Biology, Xi'an, Shaanxi, 710032, China.,Center for DNA Typing, Xi'an, Shaanxi, 710032, China
| | - Wei Liu
- Department of physiotherapy, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, 710032, China
| | - Zhipeng Fang
- Center for RNA Research, State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, The Chinese Academy of Sciences, Shanghai, 710031, China
| | - Juan Shi
- Department of Anatomy, Histology and Embryology & K.K. Leung Brain Research Centre, Preclinical School of Medicine, Fourth Military Medical University, Xi'an, Shaanxi, 200032, China
| | - Fengyu Che
- Center for DNA Typing, Xi'an, Shaanxi, 710032, China
| | - Chunxia He
- Department of Biochemistry and Molecular Biology, Xi'an, Shaanxi, 710032, China.,Center for DNA Typing, Xi'an, Shaanxi, 710032, China
| | - Libo Yao
- Department of Biochemistry and Molecular Biology, Xi'an, Shaanxi, 710032, China
| | - Enduo Wang
- Center for RNA Research, State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, The Chinese Academy of Sciences, Shanghai, 710031, China
| | - Yuanming Wu
- Department of Biochemistry and Molecular Biology, Xi'an, Shaanxi, 710032, China.,Center for DNA Typing, Xi'an, Shaanxi, 710032, China
| |
Collapse
|