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Marupudi N, Xiong MP. Genetic Targets and Applications of Iron Chelators for Neurodegeneration with Brain Iron Accumulation. ACS BIO & MED CHEM AU 2024; 4:119-130. [PMID: 38911909 PMCID: PMC11191567 DOI: 10.1021/acsbiomedchemau.3c00066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 02/15/2024] [Accepted: 02/20/2024] [Indexed: 06/25/2024]
Abstract
Neurodegeneration with brain iron accumulation (NBIA) is a group of neurodegenerative diseases that are typically caused by a monogenetic mutation, leading to development of disordered movement symptoms such as dystonia, hyperreflexia, etc. Brain iron accumulation can be diagnosed through MRI imaging and is hypothesized to be the cause of oxidative stress, leading to the degeneration of brain tissue. There are four main types of NBIA: pantothenate kinase-associated neurodegeneration (PKAN), PLA2G6-associated neurodegeneration (PLAN), mitochondrial membrane protein-associated neurodegeneration (MKAN), and beta-propeller protein-associated neurodegeneration (BPAN). There are no causative therapies for these diseases, but iron chelators have been shown to have potential toward treating NBIA. Three chelators are investigated in this Review: deferoxamine (DFO), desferasirox (DFS), and deferiprone (DFP). DFO has been investigated to treat neurodegenerative diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD); however, dose-related toxicity in these studies, as well as in PKAN studies, have shown that the drug still requires more development before it can be applied toward NBIA cases. Iron chelation therapies other than the ones currently in clinical use have not yet reached clinical studies, but they may possess characteristics that would allow them to access the brain in ways that current chelators cannot. Intranasal formulations are an attractive dosage form to study for chelation therapy, as this method of delivery can bypass the blood-brain barrier and access the CNS. Gene therapy differs from iron chelation therapy as it is a causal treatment of the disease, whereas iron chelators only target the disease progression of NBIA. Because the pathophysiology of NBIA diseases is still unclear, future courses of action should be focused on causative treatment; however, iron chelation therapy is the current best course of action.
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Affiliation(s)
- Neharika Marupudi
- Department of Pharmaceutical
& Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, Georgia 30602-2352, United States
| | - May P. Xiong
- Department of Pharmaceutical
& Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, Georgia 30602-2352, United States
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Angelini C, Durand CM, Fergelot P, Deforges J, Vital A, Menegon P, Sarrazin E, Bellance R, Mathis S, Gonzalez V, Renaud M, Frismand S, Schmitt E, Rouanet M, Burglen L, Chabrol B, Desnous B, Arveiler B, Stevanin G, Coupry I, Goizet C. Autosomal Dominant MPAN: Mosaicism Expands the Clinical Spectrum to Atypical Late-Onset Phenotypes. Mov Disord 2023; 38:2103-2115. [PMID: 37605305 DOI: 10.1002/mds.29576] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 05/31/2023] [Accepted: 07/24/2023] [Indexed: 08/23/2023] Open
Abstract
BACKGROUND Mitochondrial membrane protein-associated neurodegeneration (MPAN) is caused by mutations in the C19orf12 gene. MPAN typically appears in the first two decades of life and presents with progressive dystonia-parkinsonism, lower motor neuron signs, optic atrophy, and abnormal iron deposits predominantly in the basal ganglia. MPAN, initially considered as a strictly autosomal recessive disease (AR), turned out to be also dominantly inherited (AD). OBJECTIVES Our aim was to better characterize the clinical, molecular, and functional spectra associated with such dominant pathogenic heterozygous C19orf12 variants. METHODS We collected clinical, imaging, and molecular information of eight individuals from four AD-MPAN families and obtained brain neuropathology results for one. Functional studies, focused on energy and iron metabolism, were conducted on fibroblasts from AD-MPAN patients, AR-MPAN patients, and controls. RESULTS We identified four heterozygous C19orf12 variants in eight AD-MPAN patients. Two of them carrying the familial variant in mosaic displayed an atypical late-onset phenotype. Fibroblasts from AD-MPAN showed more severe alterations of iron storage metabolism and autophagy compared to AR-MPAN cells. CONCLUSION Our data add strong evidence of the realness of AD-MPAN with identification of novel monoallelic C19orf12 variants, including at the mosaic state. This has implications in diagnosis procedures. We also expand the phenotypic spectrum of MPAN to late onset atypical presentations. Finally, we demonstrate for the first time more drastic abnormalities of iron metabolism and autophagy in AD-MPAN than in AR-MPAN. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Chloé Angelini
- Service de Génétique Médicale, Hôpital Pellegrin, CHU Bordeaux, Bordeaux, France
- Centre de Référence Maladies Rares «Neurogénétique», Service de Génétique Médicale, CHU Bordeaux, Bordeaux, France
- University of Bordeaux, CNRS, INCIA, UMR 5287, NRGen Team, Bordeaux, France
| | - Christelle Marie Durand
- Service de Génétique Médicale, Hôpital Pellegrin, CHU Bordeaux, Bordeaux, France
- Centre de Référence Maladies Rares «Neurogénétique», Service de Génétique Médicale, CHU Bordeaux, Bordeaux, France
- University of Bordeaux, CNRS, INCIA, UMR 5287, NRGen Team, Bordeaux, France
- MRGM, University of Bordeaux, INSERM U1211, Bordeaux, France
| | - Patricia Fergelot
- Service de Génétique Médicale, Hôpital Pellegrin, CHU Bordeaux, Bordeaux, France
- MRGM, University of Bordeaux, INSERM U1211, Bordeaux, France
| | - Julie Deforges
- Service de Génétique Médicale, Hôpital Pellegrin, CHU Bordeaux, Bordeaux, France
| | - Anne Vital
- Service d'Anatomie Pathologique, Hôpital Pellegrin, CHU Bordeaux, Bordeaux, France
| | - Patrice Menegon
- Service de Neuroradiologie, Hôpital Pellegrin, CHU Bordeaux, Bordeaux, France
| | - Elizabeth Sarrazin
- Centre de Référence Maladies Rares Neuromusculaires (AOC), Hôpital Pierre Zobda Quitman, CHU Martinique, Fort de France, Martinique
| | - Rémi Bellance
- Centre de Référence Maladies Rares Neuromusculaires (AOC), Hôpital Pierre Zobda Quitman, CHU Martinique, Fort de France, Martinique
| | - Stéphane Mathis
- Service de Neurologie (Unité Nerf-Muscle), Centre de Référence Maladies Rares, Neuromusculaires (AOC), Centre SLA, Hôpital Pellegrin, CHU Bordeaux, Bordeaux, France
| | - Victoria Gonzalez
- Service de neurologie, Hôpital Gui de Chauliac, CHU Montpellier, Montpellier, France
| | - Mathilde Renaud
- Service de Neurologie, CHRU Nancy, Nancy, France
- Service de Génétique Clinique, CHRU Nancy, Nancy, France
- NGERE, INSERM U1256, Faculté de Médecine, Université de Lorraine, Nancy, France
| | | | - Emmanuelle Schmitt
- Service de Neuroradiologie Diagnostique et Thérapeutique, CHRU Nancy, Nancy, France
| | - Marie Rouanet
- Service d'explorations Fonctionnelles du Système Nerveux, Hôpital Pellegrin, CHU Bordeaux, Bordeaux, France
| | - Lydie Burglen
- Laboratoire de Neurogénétique Pédiatrique, Département de Génétique, Hôpital Trousseau, APHP.Sorbonne Université, Paris, France
| | - Brigitte Chabrol
- Service de Neuropédiatrie, Hôpital Timone enfants, APHM, Marseille, France
| | - Béatrice Desnous
- Service de Neuropédiatrie, Hôpital Timone enfants, APHM, Marseille, France
| | - Benoît Arveiler
- Service de Génétique Médicale, Hôpital Pellegrin, CHU Bordeaux, Bordeaux, France
- MRGM, University of Bordeaux, INSERM U1211, Bordeaux, France
| | - Giovanni Stevanin
- University of Bordeaux, CNRS, INCIA, UMR 5287, NRGen Team, Bordeaux, France
- EPHE, CNRS, INCIA, UMR 5287, PSL Research University, Paris, France
| | - Isabelle Coupry
- University of Bordeaux, CNRS, INCIA, UMR 5287, NRGen Team, Bordeaux, France
- MRGM, University of Bordeaux, INSERM U1211, Bordeaux, France
| | - Cyril Goizet
- Service de Génétique Médicale, Hôpital Pellegrin, CHU Bordeaux, Bordeaux, France
- Centre de Référence Maladies Rares «Neurogénétique», Service de Génétique Médicale, CHU Bordeaux, Bordeaux, France
- University of Bordeaux, CNRS, INCIA, UMR 5287, NRGen Team, Bordeaux, France
- MRGM, University of Bordeaux, INSERM U1211, Bordeaux, France
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Chen S, Lai X, Fu J, Yang J, Zhao B, Shang H, Huang R, Chen X. A novel C19ORF12 mutation in two MPAN sisters treated with deferiprone. BMC Neurol 2023; 23:134. [PMID: 37004026 PMCID: PMC10064749 DOI: 10.1186/s12883-023-03172-z] [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: 12/27/2022] [Accepted: 03/20/2023] [Indexed: 04/03/2023] Open
Abstract
BACKGROUND Mitochondrial membrane protein-associated neurodegeneration (MPAN) is a rare and devastating disease caused by pathogenic mutations in C19orf12 gene. MPAN is characterized by pathological iron accumulation in the brain and fewer than 100 cases of MPAN have been described. Although the diagnosis of MPAN has achieved a great breakthrough with the application of the whole exome gene sequencing technology, the therapeutic effect of iron chelation therapy in MPAN remains controversial. CASE PRESENTATION We reported that two sisters from the same family diagnosed with MPAN had dramatically different responses to deferiprone (DFP) treatment. The diagnosis of MPAN were established based on typical clinical manifestations, physical examination, brain magnetic resonance imaging (MRI), cerebrospinal fluid analysis (CSF) and gene sequencing results. The clinical presentations of the two sisters with MPAN due to novel gene locus mutations were similar to those previously reported. There is no other difference in basic information except that the proband had a later onset age and fertility history. Both the proband and his second sister were treated with deferiprone (DFP), but they had dramatically different responses to the treatment. The proband's condition deteriorated sharply after treatment with DFP including psychiatric symptoms and movement disorders. However, the second sister of the proband became relatively stable after receiving the DFP treatment. After four years of follow-up, the patient still denies any new symptoms of neurological deficits. CONCLUSION The findings of this study enriched the MPAN gene database and indicated that DFP might ameliorate symptom progression in patients without severe autonomic neuropsychiatric impairment at the early stage of the disease.
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Affiliation(s)
- Sihui Chen
- Department of Neurology, West China Hospital of Sichuan University, Chengdu, Sichuan Province China
| | - Xiaohui Lai
- Department of Neurology, West China Hospital of Sichuan University, Chengdu, Sichuan Province China
| | - Jiajia Fu
- Department of Neurology, West China Hospital of Sichuan University, Chengdu, Sichuan Province China
| | - Jing Yang
- Department of Neurology, West China Hospital of Sichuan University, Chengdu, Sichuan Province China
| | - Bi Zhao
- Department of Neurology, West China Hospital of Sichuan University, Chengdu, Sichuan Province China
| | - Huifang Shang
- Department of Neurology, West China Hospital of Sichuan University, Chengdu, Sichuan Province China
| | - Rui Huang
- Department of Neurology, West China Hospital of Sichuan University, Chengdu, Sichuan Province China
| | - Xueping Chen
- Department of Neurology, West China Hospital of Sichuan University, Chengdu, Sichuan Province China
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4
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A human adipose tissue cell-type transcriptome atlas. Cell Rep 2022; 40:111046. [PMID: 35830816 DOI: 10.1016/j.celrep.2022.111046] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 04/29/2022] [Accepted: 06/13/2022] [Indexed: 12/19/2022] Open
Abstract
The importance of defining cell-type-specific genes is well acknowledged. Technological advances facilitate high-resolution sequencing of single cells, but practical challenges remain. Adipose tissue is composed primarily of adipocytes, large buoyant cells requiring extensive, artefact-generating processing for separation and analysis. Thus, adipocyte data are frequently absent from single-cell RNA sequencing (scRNA-seq) datasets, despite being the primary functional cell type. Here, we decipher cell-type-enriched transcriptomes from unfractionated human adipose tissue RNA-seq data. We profile all major constituent cell types, using 527 visceral adipose tissue (VAT) or 646 subcutaneous adipose tissue (SAT) samples, identifying over 2,300 cell-type-enriched transcripts. Sex-subset analysis uncovers a panel of male-only cell-type-enriched genes. By resolving expression profiles of genes differentially expressed between SAT and VAT, we identify mesothelial cells as the primary driver of this variation. This study provides an accessible method to profile cell-type-enriched transcriptomes using bulk RNA-seq, generating a roadmap for adipose tissue biology.
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Yang Y, Zhang S, Yang W, Wei T, Hao W, Cheng T, Wang J, Dong W, Qian N. Case Report: Identification of a De novo C19orf12 Variant in a Patient With Mitochondrial Membrane Protein-Associated Neurodegeneration. Front Genet 2022; 13:852374. [PMID: 35432442 PMCID: PMC9006254 DOI: 10.3389/fgene.2022.852374] [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: 01/11/2022] [Accepted: 02/18/2022] [Indexed: 11/24/2022] Open
Abstract
Background: Mitochondrial membrane protein–associated neurodegeneration (MPAN) mostly arises as an autosomal recessive disease and is caused by variants in the chromosome 19 open reading frame 12 (C19orf12) gene. However, a few C19orf12 monoallelic truncating de novo variants have been reported and segregated as autosomal dominant traits in some cases. Methods: We performed whole-exome sequencing and analyzed genes related to neurodegeneration associated with brain iron accumulation for pathogenic variants. The identified variants were confirmed by Sanger sequencing and tested using in silico tools. Results: The patient had an onset of depression at the age of 22 years, which rapidly progressed to severe dystonia, dementia, and bladder and bowel incontinence. Neuroimaging showed hypointensity in the substantia nigra and the globus pallidum, with additional frontotemporal atrophy. Genetic analysis revealed a single complex de novo variant [c.336_338delinsCACA (p.Trp112CysfsTer40)] in the C19orf12 gene. Conclusion: This study enriches the genetic spectrum and clinical features of C19orf12 variants and provides additional evidence of the variable inheritance pattern of MPAN.
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Affiliation(s)
- Yue Yang
- Graduate School of Anhui University of Chinese Medicine, Hefei, China
| | - Shijie Zhang
- The First Affiliated Hospital of Anhui University of Chinese Medicine, Hefei, China
| | - Wenming Yang
- The First Affiliated Hospital of Anhui University of Chinese Medicine, Hefei, China.,Xin'an Medical Education Ministry Key Laboratory, Hefei, China
| | - Taohua Wei
- The First Affiliated Hospital of Anhui University of Chinese Medicine, Hefei, China
| | - Wenjie Hao
- Graduate School of Anhui University of Chinese Medicine, Hefei, China
| | - Ting Cheng
- Clinical School of Anhui Medical University, Hefei, China
| | - Jiuxiang Wang
- The First Affiliated Hospital of Anhui University of Chinese Medicine, Hefei, China
| | - Wei Dong
- Graduate School of Anhui University of Chinese Medicine, Hefei, China.,The First Affiliated Hospital of Anhui University of Chinese Medicine, Hefei, China
| | - Nannan Qian
- Graduate School of Anhui University of Chinese Medicine, Hefei, China
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SPG43 and ALS-like syndrome in the same family due to compound heterozygous mutations of the C19orf12 gene: a case description and brief review. Neurogenetics 2021; 22:95-101. [PMID: 33394258 DOI: 10.1007/s10048-020-00631-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 11/30/2020] [Indexed: 10/22/2022]
Abstract
C19orf12 gene biallelic mutations lead mainly to neurodegeneration with brain iron accumulation-4. A 15-year-old male and his 17-year-old sister complained of cramps and exercise intolerance. Clinical examination of the boy mainly showed distal amyotrophy and mild weakness, while the sister predominantly had a tetrapyramidal syndrome. Widespread chronic neurogenic signs and hypointense signals on the striatum were present in both patients. Clinical exome sequencing identified, on both patients, the compound heterozygous pathogenic mutations c.204_214del p.(Gly69ArgfsTer10) and c.32C>T p.(Thr11Met). The description of these rare SPG43 and ALS-like phenotypes in the same family contributes to improve genotype-phenotype correlation in C19orf12-related diseases.
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Rickman OJ, Salter CG, Gunning AC, Fasham J, Voutsina N, Leslie JS, McGavin L, Cross HE, Posey JE, Akdemir ZC, Jhangiani SN, Lupski JR, Baple EL, Crosby AH. Dominant mitochondrial membrane protein-associated neurodegeneration (MPAN) variants cluster within a specific C19orf12 isoform. Parkinsonism Relat Disord 2020; 82:84-86. [PMID: 33260061 DOI: 10.1016/j.parkreldis.2020.10.041] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 10/15/2020] [Accepted: 10/28/2020] [Indexed: 11/30/2022]
Abstract
Mitochondria membrane protein-associated neurodegeneration (MPAN) neurodegenerative disorder is typically associated with biallelic C19orf12 variants. Here we describe a new and review candidate previous monoallelic de novo C19orf12 variants to define loss of function mutations located in the putative non-membrane spanning C19orf12 isoform as the potential basis of monoallelic MPAN.
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Affiliation(s)
- Olivia J Rickman
- RILD Wellcome Wolfson Centre, University of Exeter Medical School, Exeter, EX2 5DW, UK
| | - Claire G Salter
- RILD Wellcome Wolfson Centre, University of Exeter Medical School, Exeter, EX2 5DW, UK; Wessex Clinical Genetics Service, Princess Anne Hospital, Southampton, SO16 5YA, UK
| | - Adam C Gunning
- RILD Wellcome Wolfson Centre, University of Exeter Medical School, Exeter, EX2 5DW, UK
| | - James Fasham
- RILD Wellcome Wolfson Centre, University of Exeter Medical School, Exeter, EX2 5DW, UK; Peninsula Clinical Genetics Service, Royal Devon and Exeter Hospital, Exeter, EX1 2ED, UK
| | - Nikol Voutsina
- RILD Wellcome Wolfson Centre, University of Exeter Medical School, Exeter, EX2 5DW, UK
| | - Joseph S Leslie
- RILD Wellcome Wolfson Centre, University of Exeter Medical School, Exeter, EX2 5DW, UK
| | - Lucy McGavin
- Department of Radiology, Derriford Hospital, Plymouth, UK
| | - Harold E Cross
- University of Arizona College of Medicine, Tucson, AZ, USA
| | - Jennifer E Posey
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA, 77030
| | - Zeynep Coban Akdemir
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA, 77030
| | - Shalini N Jhangiani
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA, 77030
| | - James R Lupski
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA, 77030; Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA, 77030; Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA, 77030; Texas Children's Hospital, Houston, TX, USA, 77030
| | - Emma L Baple
- RILD Wellcome Wolfson Centre, University of Exeter Medical School, Exeter, EX2 5DW, UK; Peninsula Clinical Genetics Service, Royal Devon and Exeter Hospital, Exeter, EX1 2ED, UK.
| | - Andrew H Crosby
- RILD Wellcome Wolfson Centre, University of Exeter Medical School, Exeter, EX2 5DW, UK.
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Nagarjunakonda S, Daggumati R, Uppala V, Gajula R, Amalakanti S. A Novel Mutation in Neurodegeneration with Brain Iron Accumulation - A Case Report. Neurol India 2019; 67:1341-1343. [PMID: 31744972 DOI: 10.4103/0028-3886.271257] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Neurodegeneration with brain iron accumulation (NBIA), previously called Hallervorden Spatz disease, is a group of disorders which share the hallmark of iron deposition in the brain. They are collectively characterized by extrapyramidal movement disorders, particularly those of parkinsonism, dystonia, cognitive regression, neuropsychiatric abnormalities, pyramidal features, optic atrophy, and retinal abnormalities. There is aberrant brain iron metabolism, with large amounts of iron deposited in the globus pallidus and the substantia nigra pars reticulata. NBIA displays a marked genetic heterogeneity, and 10 genes have been associated with different NBIA subtypes at present. We present a 12-year-old boy with a one and a half-year history of a slow, progressive gait disturbance. An MRI of his brain revealed T2, FLAIR bilateral symmetrical hypointensities in globus pallidus and substantia nigra s/o NBIA. His genetic analysis revealed a novel homozygous missense variation in exon 2 of the C19orf12 gene (chr19:30199203; A>C) that results in the amino acid substitution of valine for phenylalanine at codon 51 (p.F51V; ENST00000392278). This is consistent with the MPAN (mitochondrial membrane protein-associated neurodegeneration) subtype.
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Affiliation(s)
| | - Rajeswari Daggumati
- Department of Neurology, Government General Hospital, Guntur Medical College, Guntur, Andhra Pradesh, India
| | - Veeramma Uppala
- Department of Neurology, Government General Hospital, Guntur Medical College, Guntur, Andhra Pradesh, India
| | - Ramakrishna Gajula
- Department of Neurology, Government General Hospital, Guntur Medical College, Guntur, Andhra Pradesh, India
| | - Sridhar Amalakanti
- Department of Neurology, Government General Hospital, Guntur Medical College, Guntur, Andhra Pradesh, India
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Wang ZB, Liu JY, Xu XJ, Mao XY, Zhang W, Zhou HH, Liu ZQ. Neurodegeneration with brain iron accumulation: Insights into the mitochondria dysregulation. Biomed Pharmacother 2019; 118:109068. [PMID: 31404774 DOI: 10.1016/j.biopha.2019.109068] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 05/31/2019] [Accepted: 05/31/2019] [Indexed: 12/16/2022] Open
Abstract
NBIA (Neurodegeneration with brain iron accumulation) is a group of inherited neurologic disorders characterized by marked genetic heterogeneity, in which iron atypical accumulates in basal ganglia resulting in brain magnetic resonance imaging changes, histopathological abnormalities, and neuropsychiatric clinical symptoms. With the rapid development of high-throughput sequencing technologies, ten candidate genes have been identified, including PANK2, PLA2G6, C19orf12, WDR45, FA2H, ATP13A2, FTL, CP, C2orf37, and COASY. They are involved in seemingly unrelated cellular pathways, such as iron homeostasis (FTL, CP), lipid metabolism (PLA2G6, C19orf12, FA2H), Coenzyme A synthesis (PANK2, COASY), and autophagy (WDR45, ATP13A2). In particular, PANK2, COASY, PLA2G6, and C19orf12 are located on mitochondria, which associate with certain subtypes of NBIA showing mitochondria dysregulation. However, the relationships among those four genes are still unclear. Therefore, this review is specifically focused on dysregulation of mitochondria in NBIA and afore-mentioned four genes, with summaries of both pathological and clinical findings.
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Affiliation(s)
- Zhi-Bin Wang
- Departments of Clinical Pharmacology and National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, PR China; Institute of Clinical Pharmacology, Central South University, Hunan Key Laboratory of Pharmacogenetics, Changsha 410078, PR China
| | - Jun-Yan Liu
- Department of Orthopaedics, The First Affiliated Hospital of the University of South China, Hengyang 421001, PR China
| | - Xiao-Jing Xu
- Departments of Clinical Pharmacology and National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, PR China; Institute of Clinical Pharmacology, Central South University, Hunan Key Laboratory of Pharmacogenetics, Changsha 410078, PR China
| | - Xiao-Yuan Mao
- Departments of Clinical Pharmacology and National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, PR China; Institute of Clinical Pharmacology, Central South University, Hunan Key Laboratory of Pharmacogenetics, Changsha 410078, PR China
| | - Wei Zhang
- Departments of Clinical Pharmacology and National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, PR China; Institute of Clinical Pharmacology, Central South University, Hunan Key Laboratory of Pharmacogenetics, Changsha 410078, PR China
| | - Hong-Hao Zhou
- Departments of Clinical Pharmacology and National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, PR China; Institute of Clinical Pharmacology, Central South University, Hunan Key Laboratory of Pharmacogenetics, Changsha 410078, PR China
| | - Zhao-Qian Liu
- Departments of Clinical Pharmacology and National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, PR China; Institute of Clinical Pharmacology, Central South University, Hunan Key Laboratory of Pharmacogenetics, Changsha 410078, PR China.
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10
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Tariq H, Butt JUR, Houlden H, Naz S. Are some C19orf12 variants monoallelic for neurological disorders? Parkinsonism Relat Disord 2019; 65:267-269. [PMID: 31105013 DOI: 10.1016/j.parkreldis.2019.05.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 04/03/2019] [Accepted: 05/11/2019] [Indexed: 11/20/2022]
Affiliation(s)
- Huma Tariq
- Department of Neurogenetics, UCL Institute of Neurology, Queen Square House, University College London, London, UK; School of Biological Sciences, University of the Punjab, Lahore, Pakistan
| | | | - Henry Houlden
- Department of Neurogenetics, UCL Institute of Neurology, Queen Square House, University College London, London, UK.
| | - Sadaf Naz
- School of Biological Sciences, University of the Punjab, Lahore, Pakistan.
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Gregory A, Lotia M, Jeong SY, Fox R, Zhen D, Sanford L, Hamada J, Jahic A, Beetz C, Freed A, Kurian MA, Cullup T, van der Weijden MCM, Nguyen V, Setthavongsack N, Garcia D, Krajbich V, Pham T, Woltjer R, George BP, Minks KQ, Paciorkowski AR, Hogarth P, Jankovic J, Hayflick SJ. Autosomal dominant mitochondrial membrane protein-associated neurodegeneration (MPAN). Mol Genet Genomic Med 2019; 7:e00736. [PMID: 31087512 PMCID: PMC6625130 DOI: 10.1002/mgg3.736] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 03/21/2019] [Accepted: 04/07/2019] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND Mitochondrial membrane protein-associated neurodegeneration (MPAN) is caused by pathogenic sequence variants in C19orf12. Autosomal recessive inheritance has been demonstrated. We present evidence of autosomal dominant MPAN and propose a mechanism to explain these cases. METHODS Two large families with apparently dominant MPAN were investigated; additional singleton cases of MPAN were identified. Gene sequencing and multiplex ligation-dependent probe amplification were used to characterize the causative sequence variants in C19orf12. Post-mortem brain from affected subjects was examined. RESULTS In two multi-generation non-consanguineous families, we identified different nonsense sequence variations in C19orf12 that segregate with the MPAN phenotype. Brain pathology was similar to that of autosomal recessive MPAN. We additionally identified a preponderance of cases with single heterozygous pathogenic sequence variants, including two with de novo changes. CONCLUSIONS We present three lines of clinical evidence to demonstrate that MPAN can manifest as a result of only one pathogenic C19orf12 sequence variant. We propose that truncated C19orf12 proteins, resulting from nonsense variants in the final exon in our autosomal dominant cohort, impair function of the normal protein produced from the non-mutated allele via a dominant negative mechanism and cause loss of function. These findings impact the clinical diagnostic evaluation and counseling.
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Affiliation(s)
- Allison Gregory
- Molecular & Medical Genetics, Pediatrics and Neurology, Oregon Health & Science University, Portland, Oregon
| | - Mitesh Lotia
- Parkinson's Disease Center and Movement Disorder Clinic, Department of Neurology, Baylor College of Medicine, Houston, Texas
| | - Suh Young Jeong
- Molecular & Medical Genetics, Pediatrics and Neurology, Oregon Health & Science University, Portland, Oregon
| | - Rachel Fox
- Molecular & Medical Genetics, Pediatrics and Neurology, Oregon Health & Science University, Portland, Oregon
| | - Dolly Zhen
- Molecular & Medical Genetics, Pediatrics and Neurology, Oregon Health & Science University, Portland, Oregon
| | - Lynn Sanford
- Molecular & Medical Genetics, Pediatrics and Neurology, Oregon Health & Science University, Portland, Oregon
| | - Jeff Hamada
- Molecular & Medical Genetics, Pediatrics and Neurology, Oregon Health & Science University, Portland, Oregon
| | - Amir Jahic
- Department of Clinical Chemistry, Jena University Hospital, Jena, Germany
| | - Christian Beetz
- Department of Clinical Chemistry, Jena University Hospital, Jena, Germany
| | - Alison Freed
- Molecular & Medical Genetics, Pediatrics and Neurology, Oregon Health & Science University, Portland, Oregon
| | - Manju A Kurian
- Developmental Neurosciences, GOSH-Institute of Child Health, UCL & Department of Neurology, Great Ormond Street Hospital, London, UK
| | - Thomas Cullup
- North East Thames Regional Genetics Laboratory, London, UK
| | | | - Vy Nguyen
- Pathology, Oregon Health & Science University, Portland, Oregon
| | | | - Daphne Garcia
- Pathology, Oregon Health & Science University, Portland, Oregon
| | | | - Thao Pham
- Pathology, Oregon Health & Science University, Portland, Oregon
| | - Randy Woltjer
- Pathology, Oregon Health & Science University, Portland, Oregon
| | - Benjamin P George
- Department of Neurology, University of Rochester Medical Center, Rochester, New York
| | - Kelly Q Minks
- Department of Neurology, University of Rochester Medical Center, Rochester, New York
| | - Alexander R Paciorkowski
- Department of Neurology, University of Rochester Medical Center, Rochester, New York.,Departments of Pediatrics, Biomedical Genetics, and Neuroscience, University of Rochester Medical Center, Rochester, New York
| | - Penelope Hogarth
- Molecular & Medical Genetics, Pediatrics and Neurology, Oregon Health & Science University, Portland, Oregon
| | - Joseph Jankovic
- Parkinson's Disease Center and Movement Disorder Clinic, Department of Neurology, Baylor College of Medicine, Houston, Texas
| | - Susan J Hayflick
- Molecular & Medical Genetics, Pediatrics and Neurology, Oregon Health & Science University, Portland, Oregon
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Savitt D, Jankovic J. Levodopa-induced dyskinesias in mitochondrial membrane protein-associated neurodegeneration. Neurol Clin Pract 2019; 9:e7-e9. [PMID: 30859014 DOI: 10.1212/cpj.0000000000000577] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 09/06/2018] [Indexed: 11/15/2022]
Affiliation(s)
- Daniel Savitt
- Department of Neurology, Parkinson's Disease and Movement Disorders Clinic, Baylor College of Medicine, Houston, TX
| | - Joseph Jankovic
- Department of Neurology, Parkinson's Disease and Movement Disorders Clinic, Baylor College of Medicine, Houston, TX
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Dušek P, Školoudík D, Roth J, Dušek P. Mitochondrial membrane protein-associated neurodegeneration: a case report and literature review. Neurocase 2018; 24:161-165. [PMID: 30088953 DOI: 10.1080/13554794.2018.1506038] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Mitochondrial membrane protein-associated neurodegeneration (MPAN) is an autosomal recessive disorder caused by mutation in the C19orf12 gene. We report a compound heterozygous c.[32C>T];[205G>A;424A>G] (p.[Thr11Met];[Gly69Arg;Lys142Glu]) Czech patient who manifested with right foot dystonia, impaired handwriting, attention deficit, and signs of iron accumulation on brain MRI. Gradually, he developed dysarthria, spastic-dystonic gait, pedes cavi, and atrophy of leg muscles. Additionally, we report demographic parameters, clinical signs, and allelic frequencies of C19orf12 mutations of all published MPAN cases. We compared the most frequent mutations, p.Thr11Met and p.Gly69ArgfsX10; the latter was associated with younger age at onset and more frequent optic atrophy in homozygotes.
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Affiliation(s)
- Pavel Dušek
- a Department of Neurology, Centre of Clinical Neurosciences, 1st Faculty of Medicine , Charles University and General University Hospital , Prague , Czech Republic
| | - David Školoudík
- b Center of Research and Science, Faculty of Health Sciences , Palacký University , Olomouc , Czech Republic
| | - Jan Roth
- a Department of Neurology, Centre of Clinical Neurosciences, 1st Faculty of Medicine , Charles University and General University Hospital , Prague , Czech Republic
| | - Petr Dušek
- a Department of Neurology, Centre of Clinical Neurosciences, 1st Faculty of Medicine , Charles University and General University Hospital , Prague , Czech Republic.,c Department of Radiology, First Faculty of Medicine , Charles Universityand GeneralUniversity Hospital in Prague , Prague , Czech Republic
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Olgiati S, Doğu O, Tufekcioglu Z, Diler Y, Saka E, Gultekin M, Kaleagasi H, Kuipers D, Graafland J, Breedveld GJ, Quadri M, Sürmeli R, Sünter G, Doğan T, Yalçın AD, Bilgiç B, Elibol B, Emre M, Hanagasi HA, Bonifati V. The p.Thr11Met mutation in c19orf12 is frequent among adult Turkish patients with MPAN. Parkinsonism Relat Disord 2017; 39:64-70. [PMID: 28347615 DOI: 10.1016/j.parkreldis.2017.03.012] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 02/13/2017] [Accepted: 03/17/2017] [Indexed: 11/18/2022]
Abstract
INTRODUCTION Mutations in the C19orf12 gene cause mitochondrial membrane protein associated neurodegeneration (MPAN), an autosomal recessive form of neurodegeneration with brain iron accumulation (NBIA). A limited number of patients with C19orf12 mutations, particularly those with adult onset of symptoms, have been reported. METHODS We sequenced the entire coding region of C19orf12 in 15 Turkish adult probands with idiopathic NBIA. We also performed haplotype analysis in families with a recurrent C19orf12 mutation. Clinical features were collected using a standardized form. RESULTS Nine of our 15 probands (60%) carried the homozygous c.32C > T mutation in C19orf12 (predicted protein effect: p.Thr11Met). This homozygous mutation co-segregated with the disease in all affected relatives available for testing (16 homozygous subjects). Haplotypes across the C19orf12 locus were identical for a very small region, closest to the mutation, suggesting an old founder, or, two independent founders. The clinical phenotype was characterized by adult onset in most cases (mean 24.5 years, range 10-36), and broad spectrum, including prominent parkinsonism, pyramidal signs, psychiatric disturbances, cognitive decline, and motor axonal neuropathy, in various combinations. On T2- or susceptibility weighted-MRI images, all patients displayed bilateral hypointensities in globus pallidus and substantia nigra, without an eye-of-the-tiger sign; however, hyperintense streaking of the medial medullary lamina between the external and internal parts of globus pallidus was observed frequently. CONCLUSION The C19orf12 p.Thr11Met mutation is frequent among adult Turkish patients with MPAN. These findings contribute to the characterization of this important NBIA form, and have direct implications for genetic testing of patients of Turkish origin.
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Affiliation(s)
- Simone Olgiati
- Department of Clinical Genetics, Erasmus MC, Rotterdam, The Netherlands
| | - Okan Doğu
- Department of Neurology, Medical Faculty, Mersin University, Mersin, Turkey
| | - Zeynep Tufekcioglu
- Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Yunus Diler
- Neurology Clinic, Ümraniye Research and Training Hospital, Istanbul, Turkey
| | - Esen Saka
- Department of Neurology, Medical Faculty, Hacettepe University, Ankara, Turkey
| | - Murat Gultekin
- Department of Neurology, Erciyes University Faculty of Medicine, Kayseri, Turkey
| | - Hakan Kaleagasi
- Department of Neurology, Medical Faculty, Mersin University, Mersin, Turkey
| | - Demy Kuipers
- Department of Clinical Genetics, Erasmus MC, Rotterdam, The Netherlands
| | - Josja Graafland
- Department of Clinical Genetics, Erasmus MC, Rotterdam, The Netherlands
| | - Guido J Breedveld
- Department of Clinical Genetics, Erasmus MC, Rotterdam, The Netherlands
| | - Marialuisa Quadri
- Department of Clinical Genetics, Erasmus MC, Rotterdam, The Netherlands
| | - Reyhan Sürmeli
- Neurology Clinic, Ümraniye Research and Training Hospital, Istanbul, Turkey
| | - Gülin Sünter
- Neurology Clinic, Ümraniye Research and Training Hospital, Istanbul, Turkey
| | - Tuğrul Doğan
- Neurology Clinic, Ümraniye Research and Training Hospital, Istanbul, Turkey
| | | | - Başar Bilgiç
- Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Bülent Elibol
- Department of Neurology, Medical Faculty, Hacettepe University, Ankara, Turkey
| | - Murat Emre
- Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Hasmet A Hanagasi
- Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Vincenzo Bonifati
- Department of Clinical Genetics, Erasmus MC, Rotterdam, The Netherlands.
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Kim J, Liao YH, Ionita C, Bale AE, Darras B, Acsadi G. Mitochondrial Membrane Protein-Associated Neurodegeneration Mimicking Juvenile Amyotrophic Lateral Sclerosis. Pediatr Neurol 2016; 64:83-86. [PMID: 27671242 DOI: 10.1016/j.pediatrneurol.2016.08.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 08/16/2016] [Accepted: 08/17/2016] [Indexed: 11/26/2022]
Abstract
BACKGROUND Mitochondrial membrane protein associated neurodegeneration (MPAN) is the third most common subtype of neurodegeneration with brain iron accumulation (NBIA) and caused by mutations of the orphan gene C19ORF12 encoding a transmembrane mitochondrial protein. Like other NBIA disorders, the hallmark of neuropathology is iron deposition in the basal ganglia, but the clinical presentation is highly variable. METHODS We present the relevant clinical history, neurological examination, electrophysiological and neuroimaging tests of a currently ten-year-old girl. The genetic analysis was carried out by exome sequencing focused on known NBIA and juvenile amyotrophic lateral sclerosis (ALS) genes. RESULTS The patient presented at four years of age with progressive lower extremity weakness and generalized hypotonia. She was initially diagnosed with juvenile ALS based on clinical signs, negative brain magnetic resonance imaging (MRI) and electromyography findings. As the disease progressed, a repeat brain MRI showed iron deposition in the basal ganglia at nine years of age. Exome sequencing of genes known to be associated with NBIA revealed a compound heterozygous mutation of C19ORF12 gene. CONCLUSIONS A C19orf12 gene mutation should be considered in young children with clinical signs of progressive upper and lower motor neuron disease. Finding iron accumulation in the basal ganglia helps to focus the genetic testing, but it may not be apparent for several years.
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Affiliation(s)
- Jiyeon Kim
- University of Connecticut School of Medicine, Farmington, Connecticut
| | - Yu-Hsien Liao
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut
| | | | - Allen E Bale
- Yale University School of Medicine, New Haven, Connecticut
| | - Basil Darras
- Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Gyula Acsadi
- Children's Medical Center, University of Connecticut, Farmington, Connecticut.
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16
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Gore E, Appleby BS, Cohen ML, DeBrosse SD, Leverenz JB, Miller BL, Siedlak SL, Zhu X, Lerner AJ. Clinical and imaging characteristics of late onset mitochondrial membrane protein-associated neurodegeneration (MPAN). Neurocase 2016; 22:476-483. [PMID: 27801611 PMCID: PMC5568540 DOI: 10.1080/13554794.2016.1247458] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 10/07/2016] [Indexed: 12/14/2022]
Abstract
Young onset dementias present significant diagnostic challenges. We present the case of a 35-year-old Kuwaiti man with social withdrawal, drowsiness, irritability, anxiety, aphasia, memory loss, hypereflexia, and Parkinsonism. Brain MRI showed bilateral symmetric gradient echo hypointensities in the globi pallidi and substantiae nigrae. Left cortical hypometabolism was seen on brain fluorodeoxyglucose positron emission tomography. A cortical brain biopsy revealed a high Lewy body burden. Genetic testing revealed a homozygous p.T11M mutation in the C19orf12 gene consistent with mitochondrial membrane protein-associated neurodegeneration. This is the oldest onset age of MPAN reported.
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Affiliation(s)
- Ethan Gore
- Department of Neurology, University Hospitals Case Medical Center, Beachwood, OH, USA
| | - Brian S. Appleby
- Departments of Neurology and Psychiatry, University Hospitals Case Medical Center, 3619 Park East Drive, Beachwood, OH, USA
| | - Mark L. Cohen
- Department of Pathology, University Hospitals Case Medical Center, Cleveland, OH, USA
| | - Suzanne D. DeBrosse
- Departments of Genetics and Genome Sciences, Pediatrics, and Neurology, University Hospitals Case Medical Center, Cleveland, OH, USA
| | - James B. Leverenz
- Cleveland Clinic Lou Ruvo Center for Brain Health, Cleveland, OH, USA
| | - Bruce L. Miller
- Department of Neurology, University of California, San Francisco, San Francisco, CA, USA
| | - Sandra L. Siedlak
- Department of Pathology, Case Western Reserve University, Cleveland, OH, USA
| | - Xiongwei Zhu
- Department of Pathology, Case Western Reserve University, Cleveland, OH, USA
| | - Alan J. Lerner
- Department of Neurology, University Hospitals Case Medical Center, Beachwood, OH, USA
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Annesi G, Gagliardi M, Iannello G, Quattrone A, Iannello G, Quattrone A. Mutational analysis of COASY in an Italian patient with NBIA. Parkinsonism Relat Disord 2016; 28:150-1. [PMID: 27021474 DOI: 10.1016/j.parkreldis.2016.03.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 02/08/2016] [Accepted: 03/15/2016] [Indexed: 11/27/2022]
Affiliation(s)
- Grazia Annesi
- Institute of Molecular Bioimaging and Physiology, National Research Council, Section of Germaneto, Catanzaro, Italy.
| | - Monica Gagliardi
- Institute of Molecular Bioimaging and Physiology, National Research Council, Section of Germaneto, Catanzaro, Italy
| | - Grazia Iannello
- Institute of Molecular Bioimaging and Physiology, National Research Council, Section of Germaneto, Catanzaro, Italy
| | - Aldo Quattrone
- Institute of Molecular Bioimaging and Physiology, National Research Council, Section of Germaneto, Catanzaro, Italy
| | - Grazia Iannello
- Institute of Neurology, Department of Medical and Surgical Sciences, University Magna Graecia, Catanzaro, Italy
| | - Aldo Quattrone
- Institute of Neurology, Department of Medical and Surgical Sciences, University Magna Graecia, Catanzaro, Italy
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Kinghorn KJ, Castillo-Quan JI. Mitochondrial dysfunction and defects in lipid homeostasis as therapeutic targets in neurodegeneration with brain iron accumulation. Rare Dis 2016; 4:e1128616. [PMID: 27141409 PMCID: PMC4838319 DOI: 10.1080/21675511.2015.1128616] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 11/11/2015] [Accepted: 12/01/2015] [Indexed: 10/26/2022] Open
Abstract
The PLA2G6 gene encodes a group VIA calcium independent phospholipase A2 (iPLA2β), which hydrolyses glycerophospholipids to release fatty acids and lysophospholipids. Mutations in PLA2G6 are associated with a number of neurodegenerative disorders including neurodegeneration with brain iron accumulation (NBIA), infantile neuroaxonal dystrophy (INAD), and dystonia parkinsonism, collectively known as PLA2G6-associated neurodegeneration (PLAN). Recently Kinghorn et al. demonstrated in Drosophila and PLA2G6 mutant fibroblasts that loss of normal PLA2G6 activity is associated with mitochondrial dysfunction and mitochondrial lipid peroxidation. Furthermore, they were able to show the beneficial effects of deuterated polyunsaturated fatty acids (D-PUFAs), which reduce lipid peroxidation. D-PUFAs were able to rescue the locomotor deficits of flies lacking the fly ortholog of PLA2G6 (iPLA2-VIA), as well as the mitochondrial abnormalities in PLA2G6 mutant fibroblasts. This work demonstrated that the iPLA2-VIA knockout fly is a useful organism to dissect the mechanisms of pathogenesis of PLAN, and that further investigation is required to determine the therapeutic potential of D-PUFAs in patients with PLA2G6 mutations. The fruit fly has also been used to study some of the other genetic causes of NBIA, and here we also describe what is known about the mechanisms of pathogenesis of these NBIA variants. Mitochondrial dysfunction, defects in lipid metabolism, as well as defective Coenzyme A (CoA) biosynthesis, have all been implicated in some genetic forms of NBIA, including PANK2, CoASY, C12orf19 and FA2H.
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Affiliation(s)
- Kerri J Kinghorn
- Institute of Healthy Ageing and Department of Genetics, Environment and Evolution, University College London, London, UK; Institute of Neurology, University College London, Queen Square, London, UK
| | - Jorge Iván Castillo-Quan
- Institute of Healthy Ageing and Department of Genetics, Environment and Evolution, University College London, London, UK; Institute of Neurology, University College London, Queen Square, London, UK
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