1
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Liu J, He Y, Lwin C, Han M, Guan B, Naik A, Bender C, Moore N, Huryn LA, Sergeev YV, Qian H, Zeng Y, Dong L, Liu P, Lei J, Haugen CJ, Prasov L, Shi R, Dollfus H, Aristodemou P, Laich Y, Németh AH, Taylor J, Downes S, Krawczynski MR, Meunier I, Strassberg M, Tenney J, Gao J, Shear MA, Moore AT, Duncan JL, Menendez B, Hull S, Vincent AL, Siskind CE, Traboulsi EI, Blackstone C, Sisk RA, Miraldi Utz V, Webster AR, Michaelides M, Arno G, Synofzik M, Hufnagel RB. Neuropathy target esterase activity defines phenotypes among PNPLA6 disorders. Brain 2024:awae055. [PMID: 38735647 DOI: 10.1093/brain/awae055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 01/08/2024] [Accepted: 01/28/2024] [Indexed: 05/14/2024] Open
Abstract
Biallelic pathogenic variants in the PNPLA6 gene cause a broad spectrum of disorders leading to gait disturbance, visual impairment, anterior hypopituitarism and hair anomalies. PNPLA6 encodes neuropathy target esterase (NTE), yet the role of NTE dysfunction on affected tissues in the large spectrum of associated disease remains unclear. We present a systematic evidence-based review of a novel cohort of 23 new patients along with 95 reported individuals with PNPLA6 variants that implicate missense variants as a driver of disease pathogenesis. Measuring esterase activity of 46 disease-associated and 20 common variants observed across PNPLA6-associated clinical diagnoses unambiguously reclassified 36 variants as pathogenic and 10 variants as likely pathogenic, establishing a robust functional assay for classifying PNPLA6 variants of unknown significance. Estimating the overall NTE activity of affected individuals revealed a striking inverse relationship between NTE activity and the presence of retinopathy and endocrinopathy. This phenomenon was recaptured in vivo in an allelic mouse series, where a similar NTE threshold for retinopathy exists. Thus, PNPLA6 disorders, previously considered allelic, are a continuous spectrum of pleiotropic phenotypes defined by an NTE genotype:activity:phenotype relationship. This relationship, and the generation of a preclinical animal model, pave the way for therapeutic trials, using NTE as a biomarker.
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Affiliation(s)
- James Liu
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yi He
- Fermentation Facility, Biochemistry and Biophysics Center, National Heart, Lung and Blood Institute, Bethesda, MD 20892, USA
| | - Cara Lwin
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Marina Han
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Bin Guan
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Amelia Naik
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Chelsea Bender
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Nia Moore
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Laryssa A Huryn
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yuri V Sergeev
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Haohua Qian
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yong Zeng
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Lijin Dong
- Genetic Engineering Core, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Pinghu Liu
- Genetic Engineering Core, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jingqi Lei
- Genetic Engineering Core, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Carl J Haugen
- Genetic Engineering Core, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Lev Prasov
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, MI 48105, USA
- Department of Human Genetics, University of Michigan, Ann Arbor, MI 48105, USA
| | - Ruifang Shi
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, 100730 Beijing, China
| | - Hélène Dollfus
- Centre de référence pour les Affections Rares Ophtalmologiques CARGO, Hôpitaux Universitaires de Strasbourg, Université de Strasbourg, UMRS_1112, Strasbourg 67091, France
| | - Petros Aristodemou
- Cyprus Institute of Neurology and Genetics, Nicosia 1683, Cyprus
- VRMCy Centre, Limassol 3025, Cyprus
| | - Yannik Laich
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
- Department of Genetics, Moorfields Eye Hospital NHS Trust, London EC1V 2PD, UK
| | - Andrea H Németh
- Oxford Centre for Genomic Medicine, Oxford University Hospitals NHS Foundation Trust, ACE Building, Nuffield Orthopaedic Centre, Oxford OX3 7HE, UK
- Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - John Taylor
- Oxford Regional Genetics Laboratory, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
| | - Susan Downes
- Nuffield Department of Ophthalmology, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford OX3 9DU, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
| | - Maciej R Krawczynski
- Department of Medical Genetics, Poznan University of Medical Sciences, Poznan 60-512, Poland
| | - Isabelle Meunier
- National Referent Centre for Rare Sensory Diseases, Montpellier University Hospital, Montpellier University, Montpellier 34295, France
| | | | - Jessica Tenney
- Division of Medical Genetics, Department of Pediatrics, UCSF School of Medicine, San Francisco, CA 94143, USA
| | - Josephine Gao
- Division of Medical Genetics, Department of Pediatrics, UCSF School of Medicine, San Francisco, CA 94143, USA
| | - Matthew A Shear
- Division of Medical Genetics, Department of Pediatrics, UCSF School of Medicine, San Francisco, CA 94143, USA
| | - Anthony T Moore
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
- Department of Ophthalmology, UCSF School of Medicine, San Francisco, CA 94143, USA
| | - Jacque L Duncan
- Department of Ophthalmology, UCSF School of Medicine, San Francisco, CA 94143, USA
| | - Beatriz Menendez
- Department of Pediatrics, University of Illinois School of Medicine, Chicago, IL 60612, USA
| | - Sarah Hull
- Department of Ophthalmology, University of Auckland, Auckland 1023, New Zealand
| | - Andrea L Vincent
- Department of Ophthalmology, University of Auckland, Auckland 1023, New Zealand
| | - Carly E Siskind
- Neurology and Neurological Sciences, Stanford School of Medicine, Stanford, CA 94305, USA
| | - Elias I Traboulsi
- The Center for Genetic Eye Diseases, The Cleveland Clinic Eye Institute, Cleveland, OH 44106, USA
| | - Craig Blackstone
- Movement Disorders Division, Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Robert A Sisk
- Department of Ophthalmology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Virginia Miraldi Utz
- Department of Ophthalmology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
- Abrahamson Pediatric Eye Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Andrew R Webster
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
- Department of Genetics, Moorfields Eye Hospital NHS Trust, London EC1V 2PD, UK
| | - Michel Michaelides
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
- Department of Genetics, Moorfields Eye Hospital NHS Trust, London EC1V 2PD, UK
| | - Gavin Arno
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
- Department of Genetics, Moorfields Eye Hospital NHS Trust, London EC1V 2PD, UK
| | - Matthis Synofzik
- Division Translational Genomics of Neurodegenerative Diseases Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen 72076, Germany
- German Center of Neurodegenerative Diseases (DZNE), Tübingen 72076, Germany
| | - Robert B Hufnagel
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
- Department of Genetics and Center for Integrated Healthcare Research, Kaiser Permanente Hawaii Region, Honolulu, HI 98619, USA
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2
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Liampas A, Nicolaou P, Votsi C, Georghiou A, Christodoulou K, Tanteles GA, Pantzaris M. Two case reports of a novel missense mutation in the PNPLA6 gene in two siblings with chorioretinal dystrophy, hypogonadotropic hypogonadism, and cerebellar ataxia. Mol Biol Rep 2024; 51:590. [PMID: 38683245 DOI: 10.1007/s11033-024-09515-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Accepted: 04/03/2024] [Indexed: 05/01/2024]
Abstract
BACKGROUND Boucher Neuhäuser Syndrome (BNS) is a rare disease with autosomal recessive inheritance defined by the classical triad; early-onset ataxia, hypogonadism and chorioretinal dystrophy. CASE PRESENTATION We present two siblings diagnosed with BNS at midlife, identified with homozygous state of a novel PNPLA6 missense mutation. One healthy sibling and the mother were heterozygous carriers of the mutation. The proband presented with the classical triad and the other sibling presented with visual problems at first. The proband was referred to our department by a private Neurologist, in early adulthood, because of hypogonadism, cerebellar ataxia, axonal neuropathy, and chorioretinal dystrophy for further evaluation. The sibling was referred to our department for evaluation, at childhood, due to visual problems. Later, the patient displayed the triad of ataxia, hypogonadotropic hypogonadism, and chorioretinal dystrophy. The unusual medical history of the two siblings led to further examinations and eventually the diagnosis of the first BNS cases in Cyprus. WES-based ataxia in silico gene panel analysis revealed 15 genetic variants and further filtering analysis revealed the PNPLA6 c.3323G > A variant. Segregation analysis in the family with Sanger sequencing confirmed the PNPLA6 homozygous variant c.3323G > A, p.Arg1108Gln in exon 29. CONCLUSIONS This highlights the importance of considering rare inherited causes of visual loss, spinocerebellar ataxia, or/and HH in a neurology clinic and the significant role of genetic sequencing in the diagnostic process.
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Affiliation(s)
- Andreas Liampas
- Neuroimmunology Department, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus.
| | - Paschalis Nicolaou
- Neurogenetics Department, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Christina Votsi
- Neurogenetics Department, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Anthi Georghiou
- Neurogenetics Department, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Kyproula Christodoulou
- Neurogenetics Department, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - George A Tanteles
- Medical Genetics Department, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Marios Pantzaris
- Neuroimmunology Department, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
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3
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Scaravilli A, Tranfa M, Pontillo G, Brais B, De Michele G, La Piana R, Saccà F, Santorelli FM, Synofzik M, Brunetti A, Cocozza S. A Review of Brain and Pituitary Gland MRI Findings in Patients with Ataxia and Hypogonadism. CEREBELLUM (LONDON, ENGLAND) 2024; 23:757-774. [PMID: 37155088 DOI: 10.1007/s12311-023-01562-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/26/2023] [Indexed: 05/10/2023]
Abstract
The association of cerebellar ataxia and hypogonadism occurs in a heterogeneous group of disorders, caused by different genetic mutations often associated with a recessive inheritance. In these patients, magnetic resonance imaging (MRI) plays a pivotal role in the diagnostic workflow, with a variable involvement of the cerebellar cortex, alone or in combination with other brain structures. Neuroimaging involvement of the pituitary gland is also variable. Here, we provide an overview of the main clinical and conventional brain and pituitary gland MRI imaging findings of the most common genetic mutations associated with the clinical phenotype of ataxia and hypogonadism, with the aim of helping neuroradiologists in the identification of these disorders.
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Affiliation(s)
- Alessandra Scaravilli
- Department of Advanced Biomedical Sciences, University of Naples "Federico II", Via Pansini 5, 80131, Naples, Italy
| | - Mario Tranfa
- Department of Advanced Biomedical Sciences, University of Naples "Federico II", Via Pansini 5, 80131, Naples, Italy
| | - Giuseppe Pontillo
- Department of Advanced Biomedical Sciences, University of Naples "Federico II", Via Pansini 5, 80131, Naples, Italy
- Department of Electrical Engineering and Information Technology (DIETI), University of Naples "Federico II", Naples, Italy
| | - Bernard Brais
- Department of Neurology and Neurosurgery, Montreal Neurological Hospital and Institute, Montreal, Canada
| | - Giovanna De Michele
- Department of Neurosciences and Reproductive and Odontostomatological Sciences, University of Naples "Federico II", Naples, Italy
| | - Roberta La Piana
- Department of Neurology and Neurosurgery, Montreal Neurological Hospital and Institute, Montreal, Canada
| | - Francesco Saccà
- Department of Neurosciences and Reproductive and Odontostomatological Sciences, University of Naples "Federico II", Naples, Italy
| | | | - Matthis Synofzik
- German Center for Neurodegenerative Diseases (DZNE), Tubingen, Germany
- Division Translational Genomics of Neurodegenerative Diseases, Center for Neurology and Hertie Institute for Clinical Brain Research, University of Tübingen, Otfried-Müller-Strasse 27, 72076, Tubingen, Germany
| | - Arturo Brunetti
- Department of Advanced Biomedical Sciences, University of Naples "Federico II", Via Pansini 5, 80131, Naples, Italy
| | - Sirio Cocozza
- Department of Advanced Biomedical Sciences, University of Naples "Federico II", Via Pansini 5, 80131, Naples, Italy.
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Liu J, Hufnagel RB. PNPLA6 disorders: what's in a name? Ophthalmic Genet 2023; 44:530-538. [PMID: 37732399 PMCID: PMC10840751 DOI: 10.1080/13816810.2023.2254830] [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: 05/30/2023] [Accepted: 08/26/2023] [Indexed: 09/22/2023]
Abstract
BACKGROUND Variants in the patatin-like phospholipase domain containing 6 (PNPLA6) gene cause a broad spectrum of neurological disorders characterized by gait disturbance, visual impairment, anterior hypopituitarism, and hair anomalies. This review examines the clinical, cellular, and biochemical features found across the five PNPLA6-related diseases, with a focus on future questions to be addressed. MATERIALS AND METHODS A literature review was performed on published clinical reports on patients with PNPLA6 variants. Additionally, in vitro and in vivo models used to study the encoded protein, Neuropathy Target Esterase (NTE), are summarized to lend mechanistic perspective to human diseases. RESULTS Biallelic pathogenic PNPLA6 variants cause five systemic neurological disorders: spastic paraplegia type 39, Gordon-Holmes, Boucher-Neuhäuser, Laurence-Moon, and Oliver-McFarlane syndromes. PNPLA6 encodes NTE, an enzyme involved in maintaining phospholipid homeostasis and trafficking in the nervous system. Retinal disease presents with a unique chorioretinal dystrophy that is phenotypically similar to choroideremia and Leber congenital amaurosis. Animal and cellular models support a loss-of-function mechanism. CONCLUSIONS Clinicians should be aware of choroideremia-like ocular presentation in patients who also experience growth defects, motor dysfunction, and/or hair anomalies. Although NTE biochemistry is well characterized, further research on the relationship between genotype and the presence or absence of retinopathy should be explored to improve diagnosis and prognosis.
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Affiliation(s)
- James Liu
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Robert B Hufnagel
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
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5
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Teive HA, Coutinho L, Meira AT, Franklin GL, Camargo CHF, Munhoz RP. Autosomal Recessive Cerebellar Ataxias: New Acronyms, Old Eponyms, and the Butterfly Life Cycle. Mov Disord Clin Pract 2023; 10:1297-1301. [PMID: 37772306 PMCID: PMC10525046 DOI: 10.1002/mdc3.13835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Revised: 06/14/2023] [Accepted: 06/26/2023] [Indexed: 09/30/2023] Open
Affiliation(s)
- Hélio A.G. Teive
- Movement Disorders Unit, Neurology Service, Internal Medicine Department, Hospital de ClínicasFederal University of ParanáCuritibaParanáBrazil
- Neurological Diseases Group, Graduate Program in Internal Medicine, Internal Medicine Department, Hospital de ClínicasFederal University of ParanáCuritibaParanáBrazil
| | - Léo Coutinho
- Movement Disorders Unit, Neurology Service, Internal Medicine Department, Hospital de ClínicasFederal University of ParanáCuritibaParanáBrazil
| | - Alex T. Meira
- Movement Disorders Unit, Neurology Service, Internal Medicine DepartmentFederal University of ParaíbaJoão PessoaParaíbaBrazil
| | - Gustavo L. Franklin
- Internal Medicine DepartmentPontifical Catholic University of ParanáCuritibaParanáBrazil
| | - Carlos Henrique F. Camargo
- Neurological Diseases Group, Graduate Program in Internal Medicine, Internal Medicine Department, Hospital de ClínicasFederal University of ParanáCuritibaParanáBrazil
| | - Renato Puppi Munhoz
- Division of NeurologyUniversity of Toronto, Toronto Western Hospital–University Health Network, Morton and Gloria Shulman Movement Disorders Centre and Edmond J. Safra Program in Parkinson's DiseaseTorontoOntarioCanada
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6
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Liu J, He Y, Lwin C, Han M, Guan B, Naik A, Bender C, Moore N, Huryn LA, Sergeev Y, Qian H, Zeng Y, Dong L, Liu P, Lei J, Haugen CJ, Prasov L, Shi R, Dollfus H, Aristodemou P, Laich Y, Németh AH, Taylor J, Downes S, Krawczynski M, Meunier I, Strassberg M, Tenney J, Gao J, Shear MA, Moore AT, Duncan JL, Menendez B, Hull S, Vincent A, Siskind CE, Traboulsi EI, Blackstone C, Sisk R, Utz V, Webster AR, Michaelides M, Arno G, Synofzik M, Hufnagel RB. Neuropathy target esterase activity predicts retinopathy among PNPLA6 disorders. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.09.544373. [PMID: 37333224 PMCID: PMC10274907 DOI: 10.1101/2023.06.09.544373] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Biallelic pathogenic variants in the PNPLA6 gene cause a broad spectrum of disorders leading to gait disturbance, visual impairment, anterior hypopituitarism, and hair anomalies. PNPLA6 encodes Neuropathy target esterase (NTE), yet the role of NTE dysfunction on affected tissues in the large spectrum of associated disease remains unclear. We present a clinical meta-analysis of a novel cohort of 23 new patients along with 95 reported individuals with PNPLA6 variants that implicate missense variants as a driver of disease pathogenesis. Measuring esterase activity of 46 disease-associated and 20 common variants observed across PNPLA6 -associated clinical diagnoses unambiguously reclassified 10 variants as likely pathogenic and 36 variants as pathogenic, establishing a robust functional assay for classifying PNPLA6 variants of unknown significance. Estimating the overall NTE activity of affected individuals revealed a striking inverse relationship between NTE activity and the presence of retinopathy and endocrinopathy. This phenomenon was recaptured in vivo in an allelic mouse series, where a similar NTE threshold for retinopathy exists. Thus, PNPLA6 disorders, previously considered allelic, are a continuous spectrum of pleiotropic phenotypes defined by an NTE genotype:activity:phenotype relationship. This relationship and the generation of a preclinical animal model pave the way for therapeutic trials, using NTE as a biomarker.
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7
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The phospholipase A 2 superfamily as a central hub of bioactive lipids and beyond. Pharmacol Ther 2023; 244:108382. [PMID: 36918102 DOI: 10.1016/j.pharmthera.2023.108382] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 03/06/2023] [Accepted: 03/07/2023] [Indexed: 03/13/2023]
Abstract
In essence, "phospholipase A2" (PLA2) means a group of enzymes that release fatty acids and lysophospholipids by hydrolyzing the sn-2 position of glycerophospholipids. To date, more than 50 enzymes possessing PLA2 or related lipid-metabolizing activities have been identified in mammals, and these are subdivided into several families in terms of their structures, catalytic mechanisms, tissue/cellular localizations, and evolutionary relationships. From a general viewpoint, the PLA2 superfamily has mainly been implicated in signal transduction, driving the production of a wide variety of bioactive lipid mediators. However, a growing body of evidence indicates that PLA2s also contribute to phospholipid remodeling or recycling for membrane homeostasis, fatty acid β-oxidation for energy production, and barrier lipid formation on the body surface. Accordingly, PLA2 enzymes are considered one of the key regulators of a broad range of lipid metabolism, and perturbation of specific PLA2-driven lipid pathways often disrupts tissue and cellular homeostasis and may be associated with a variety of diseases. This review covers current understanding of the physiological functions of the PLA2 superfamily, focusing particularly on the two major intracellular PLA2 families (Ca2+-dependent cytosolic PLA2s and Ca2+-independent patatin-like PLA2s) as well as other PLA2 families, based on studies using gene-manipulated mice and human diseases in combination with comprehensive lipidomics.
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8
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Kazanci S, Witt J, Su K, Lorenzo‐Betancor O, Yearout D, Zabetian CP, Davis MY. PNPLA6-Related Disorder with Levodopa-Responsive Parkinsonism. Mov Disord Clin Pract 2023; 10:338-340. [PMID: 36825042 PMCID: PMC9941917 DOI: 10.1002/mdc3.13632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 10/21/2022] [Accepted: 11/05/2022] [Indexed: 12/12/2022] Open
Affiliation(s)
- Serdar Kazanci
- Department of NeurologyUniversity of Washington Medical CenterSeattleWAUSA
| | - Jennifer Witt
- Booth Gardner Parkinson's Care CenterEvergreen Hospital Medical CenterKirklandWAUSA
| | - Kimmy Su
- Department of NeurologyUniversity of Washington Medical CenterSeattleWAUSA
- VA Puget Sound Healthcare SystemSeattleWAUSA
| | - Oswaldo Lorenzo‐Betancor
- Department of NeurologyUniversity of Washington Medical CenterSeattleWAUSA
- VA Puget Sound Healthcare SystemSeattleWAUSA
| | - Dora Yearout
- Department of NeurologyUniversity of Washington Medical CenterSeattleWAUSA
- VA Puget Sound Healthcare SystemSeattleWAUSA
| | - Cyrus P. Zabetian
- Department of NeurologyUniversity of Washington Medical CenterSeattleWAUSA
- VA Puget Sound Healthcare SystemSeattleWAUSA
| | - Marie Y. Davis
- Department of NeurologyUniversity of Washington Medical CenterSeattleWAUSA
- VA Puget Sound Healthcare SystemSeattleWAUSA
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9
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Amore G, Spoto G, Scuderi A, Prato A, Dicanio D, Nicotera A, Farello G, Chimenz R, Ceravolo I, Salpietro V, Gitto E, Ceravolo G, Iapadre G, Rosa GD, Pironti E. Bardet–Biedl Syndrome: A Brief Overview on Clinics and Genetics. JOURNAL OF PEDIATRIC NEUROLOGY 2022. [DOI: 10.1055/s-0042-1759534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
AbstractBardet–Biedl syndrome is a genetically pleiotropic disorder characterized by high clinical heterogeneity with severe multiorgan impairment. Clinically, it encompasses primary and secondary manifestations, mainly including retinal dystrophy, mental retardation, obesity, polydactyly, hypogonadism in male, and renal abnormalities. At least 21 different genes have been identified, all involved into primary cilium structure or function. To date, genotype–phenotype correlation is still poor.
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Affiliation(s)
- Greta Amore
- Department of Human Pathology of the Adult and Developmental Age “Gaetano Barresi,” Unit of Child Neurology and Psychiatry, University of Messina, Messina, Italy
| | - Giulia Spoto
- Department of Human Pathology of the Adult and Developmental Age “Gaetano Barresi,” Unit of Child Neurology and Psychiatry, University of Messina, Messina, Italy
| | - Anna Scuderi
- Department of Human Pathology of the Adult and Developmental Age “Gaetano Barresi,” Unit of Child Neurology and Psychiatry, University of Messina, Messina, Italy
| | - Adriana Prato
- Department of Human Pathology of the Adult and Developmental Age “Gaetano Barresi,” Unit of Child Neurology and Psychiatry, University of Messina, Messina, Italy
| | - Daniela Dicanio
- Department of Human Pathology of the Adult and Developmental Age “Gaetano Barresi,” Unit of Child Neurology and Psychiatry, University of Messina, Messina, Italy
| | - Antonio Nicotera
- Department of Human Pathology of the Adult and Developmental Age “Gaetano Barresi,” Unit of Child Neurology and Psychiatry, University of Messina, Messina, Italy
| | - Giovanni Farello
- Pediatric Clinic–Department of Life, Health and Environmental Sciences–Piazzale Salvatore Tommasi 1, Coppito (AQ), Italy
| | - Roberto Chimenz
- Faculty of Medicine and Surgery, University of Messina, Messina, Italy
| | - Ida Ceravolo
- Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | | | - Eloisa Gitto
- Neonatal and Pediatric Intensive Care Unit, Department of Human Pathology in Adult and Developmental Age “Gaetano Barresi,” University of Messina, Messina, Italy
| | - Giorgia Ceravolo
- Department of Human Pathology of the Adult and Developmental Age “Gaetano Barresi,” Unit of Pediatric Emergency, University of Messina, Messina, Italy
| | - Giulia Iapadre
- Department of Pediatrics, University of L'Aquila, L'Aquila, Italy
| | - Gabriella Di Rosa
- Department of Human Pathology of the Adult and Developmental Age “Gaetano Barresi,” Unit of Child Neurology and Psychiatry, University of Messina, Messina, Italy
| | - Erica Pironti
- Department of Woman-Child, Unit of Child Neurology and Psychiatry, Ospedali Riuniti, University of Foggia, Foggia, Italy
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10
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Novel phenotype with prominent cerebellar oculomotor dysfunction in spastic paraplegia type 39. J Neurol 2022; 269:6476-6482. [PMID: 35947152 PMCID: PMC9618546 DOI: 10.1007/s00415-022-11313-6] [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: 05/31/2022] [Revised: 07/23/2022] [Accepted: 07/25/2022] [Indexed: 11/16/2022]
Abstract
Objectives The term hereditary spastic paraplegia comprises an ever-expanding array of neurological disorders with distinct aetiologies. Spastic paraplegia gene 39 is one of the many genetically defined types with features of other organs and neurological systems in addition to paraspasticity. We describe a large kindred with a novel clinical phenotype as, in addition to spastic paraplegia, affected subjects suffered from a prominent cerebellar oculomotor dysfunction with two hitherto undescribed mutations of PNPLA6. Methods Three of five genetically tested family members of a large kindred were affected by spastic gait and a unique and prominent cerebellar oculomotor dysfunction. Further clinical, imaging, laboratory and videonystagmographic data were analyzed. Genetic analysis was done using next-generation sequencing. Results The most salient clinical feature, in addition to paraspasticity, in three of five subjects was cerebellar oculomotor dysfunction with an upbeating nystagmus provoked by downward gaze. Genetic analysis revealed two hitherto unknown sequence variants in the PNPLA6 gene, a splice-site variant c.1635 + 3G > T and a missense variant c.3401A > T, p.(Asp1134Val). In addition to cerebellar oculomotor dysfunction, compound-heterozygous siblings presented with paraspasticity and a moderate hypogonadotropic hypogonadism in the female. A paternal uncle being homozygous for the splice-site variant of PNPLA6 presented with increased lower limb reflexes and an unstable gait. Treatment with 4-aminopyridine, a potassium channel blocker, lead to meaningful improvement of clinical symptoms. Conclusions The unique and prominent cerebellar ocular motor disorder in our family broadens the spectrum of clinical phenotypes associated with variations in the PNLA6 gene. The finding of paraspasticity with cerebellar oculomotor dysfunction alongside inconspicuous brainstem imaging may raise suspicion of complex HSP with PNPLA6 mutations. Supplementary Information The online version contains supplementary material available at 10.1007/s00415-022-11313-6.
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Parameswarappa DC, Das AV, Thakur PS, Takkar B, Multani PK, Padhy SK, Doctor MB, Agarwal K, Jalali S. Retinitis pigmentosa in Laurence-Moon-Bardet-Biedl syndrome in India: Electronic medical records driven big data analytics: Report II. Indian J Ophthalmol 2022; 70:2533-2538. [PMID: 35791150 PMCID: PMC9426086 DOI: 10.4103/ijo.ijo_2268_21] [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] [Indexed: 12/04/2022] Open
Abstract
Purpose: To describe the clinical presentation and demographic distribution of retinitis pigmentosa (RP) in Laurence–Moon–Bardet–Biedl (LMBB) syndrome patients. Methods: This is a cross-sectional observational hospital-based study wherein 244 patients with RP in LMBB syndrome presenting to our hospital network between March 2012 and October 2020 were included. An electronic medical record database was used for data retrieval. Results: There were 244 patients in total, with a hospital-based prevalence rate of 0.010% or 1000/100,000 population. The mean and median age of patients was 15.22 ± 7.56 and 14 (IQR: 10–18.5) years, respectively, with the majority being in the age group of 11–20 years (133/244 patients; 54.50%). Males were more commonly affected (164 patients; 67.21%), and the majority (182 patients; 74.59%) were students. All 244 patients (100%) complained of defective central vision at presentation. More than one-fourth of the patients had severe visual impairment to blindness at presentation. Prominent retinal feature at presentation was diffuse or widespread retinal pigment epithelial degeneration in all patients. Conclusion: Patients with RP in LMBB syndrome present mainly in the first to second decade of life with severe visual acuity impairment to blindness early in life. It is important to rule out LMBB syndrome in early-onset RP with central visual acuity impairment. On the contrary, all patients diagnosed or suspected with LMBB syndrome systemic features at physician clinic should also be referred for ophthalmic evaluation, low vision assessment, rehabilitation, and vice versa.
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Affiliation(s)
| | - Anthony V Das
- Department of eyeSmart EMR and AEye; Standard Charted Eye Care Education, L V Prasad Eye Institute, Hyderabad, Telangana, India
| | - Pratima S Thakur
- Srimati Kanuri Santhamma Center for Vitreo - Retinal Diseases; Standard Charted Eye Care Education, L V Prasad Eye Institute, Hyderabad, Telangana, India
| | - Brijesh Takkar
- Srimati Kanuri Santhamma Center for Vitreo - Retinal Diseases; Indian Health Outcomes, Public Health and Economics Research Center, L V Prasad Eye Institute, Hyderabad, Telangana, India
| | - Prabhjot K Multani
- Retina and Uveitis Department, GMR Varalakshmi Campus, L V Prasad Eye Institute, Visakhapatnam, Andhra Pradesh, India
| | - Srikant K Padhy
- Vitreoretina and Uveitis Services, Mithu Tulasi Chanrai Campus, L V Prasad Eye Institute, Bhubaneswar, Odisha, India
| | - Mariya B Doctor
- Department of Standard Charted Eye Care Education, L V Prasad Eye Institute, Hyderabad, Telangana, India
| | - Komal Agarwal
- Srimati Kanuri Santhamma Center for Vitreo - Retinal Diseases, Hyderabad, Telangana, India
| | - Subhadra Jalali
- Srimati Kanuri Santhamma Center for Vitreo - Retinal Diseases, Hyderabad, Telangana, India
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Lipid Dyshomeostasis and Inherited Cerebellar Ataxia. Mol Neurobiol 2022; 59:3800-3828. [PMID: 35420383 PMCID: PMC9148275 DOI: 10.1007/s12035-022-02826-2] [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: 03/29/2021] [Accepted: 04/01/2022] [Indexed: 12/04/2022]
Abstract
Cerebellar ataxia is a form of ataxia that originates from dysfunction of the cerebellum, but may involve additional neurological tissues. Its clinical symptoms are mainly characterized by the absence of voluntary muscle coordination and loss of control of movement with varying manifestations due to differences in severity, in the site of cerebellar damage and in the involvement of extracerebellar tissues. Cerebellar ataxia may be sporadic, acquired, and hereditary. Hereditary ataxia accounts for the majority of cases. Hereditary ataxia has been tentatively divided into several subtypes by scientists in the field, and nearly all of them remain incurable. This is mainly because the detailed mechanisms of these cerebellar disorders are incompletely understood. To precisely diagnose and treat these diseases, studies on their molecular mechanisms have been conducted extensively in the past. Accumulating evidence has demonstrated that some common pathogenic mechanisms exist within each subtype of inherited ataxia. However, no reports have indicated whether there is a common mechanism among the different subtypes of inherited cerebellar ataxia. In this review, we summarize the available references and databases on neurological disorders characterized by cerebellar ataxia and show that a subset of genes involved in lipid homeostasis form a new group that may cause ataxic disorders through a common mechanism. This common signaling pathway can provide a valuable reference for future diagnosis and treatment of ataxic disorders.
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PNPLA6/NTE, an Evolutionary Conserved Phospholipase Linked to a Group of Complex Human Diseases. Metabolites 2022; 12:metabo12040284. [PMID: 35448471 PMCID: PMC9025805 DOI: 10.3390/metabo12040284] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 03/18/2022] [Accepted: 03/22/2022] [Indexed: 12/27/2022] Open
Abstract
Patatin-like phospholipase domain-containing protein 6 (PNPLA6), originally called Neuropathy Target Esterase (NTE), belongs to a family of hydrolases with at least eight members in mammals. PNPLA6/NTE was first identified as a key factor in Organophosphate-induced delayed neuropathy, a degenerative syndrome that occurs after exposure to organophosphates found in pesticides and nerve agents. More recently, mutations in PNPLA6/NTE have been linked with a number of inherited diseases with diverse clinical symptoms that include spastic paraplegia, ataxia, and chorioretinal dystrophy. A conditional knockout of PNPLA6/NTE in the mouse brain results in age-related neurodegeneration, whereas a complete knockout causes lethality during embryogenesis due to defects in the development of the placenta. PNPLA6/NTE is an evolutionarily conserved protein that in Drosophila is called Swiss-Cheese (SWS). Loss of SWS in the fly also leads to locomotory defects and neuronal degeneration that progressively worsen with age. This review will describe the identification of PNPLA6/NTE, its expression pattern, and normal role in lipid homeostasis, as well as the consequences of altered NPLA6/NTE function in both model systems and patients.
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He J, Liu X, Liu L, Zeng S, Shan S, Liao Z. Identification of Novel Compound Heterozygous Variants of the PNPLA6 Gene in Boucher-Neuhäuser Syndrome. Front Genet 2022; 13:810537. [PMID: 35198007 PMCID: PMC8859865 DOI: 10.3389/fgene.2022.810537] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 01/05/2022] [Indexed: 12/11/2022] Open
Abstract
Background: Boucher–Neuhäuser syndrome (BNS, MIM 215470) is a rare autosomal recessive syndrome caused by mutations in the PNPLA6 gene. Few BNS cases have been reported for functional validation at the RNA level. Herein, we report on the family of a 17-year-old girl with clinical characteristics of BNS, genetic validation, and a systematic review of PNPLA6 variants related to BNS. Methods: Clinical data and blood samples were collected from the patient and their parents, and whole-exome sequencing was performed and confirmed by Sanger sequencing. RNA-sequencing (RNA-Seq) and quantitative RT-PCR (qRT-PCR) were performed, and the three-dimensional protein structures of the variants were predicted. Results: We report a 17-year-old female with progressive night blindness since the age of four, primary amenorrhea, and non-development of secondary sexual characteristics. Her impaired vision was diagnosed as retinal pigmentary degeneration of the retina. She had congenital hypogonadotropic hypogonadism (CHH) but no cerebellar ataxia at present. Two novel compound heterozygous variants (c.2241del/p.Met748TrpfsTer65 and c.2986A>G/p.Thr996Ala) of the PNPLA6 gene (NM_006702.4) were identified by whole-exome sequencing. The former variant was carried from her healthy father and has not been reported previously. The latter was inherited from her healthy mother and was noted in a report without functional studies. The RT-PCR results showed that the mRNA expression of PNPLA6 was lower in this patient and her father than in the control group. She was diagnosed with BNS. Both variants (c.2241del and c.2986A>G) were likely pathogenic according to the ACMG criteria. The novel variants in the PNPLA6 gene related to Boucher–Neuhäuser syndrome were summarized in this article. Conclusion: The possibility of Boucher–Neuhäuser syndrome should be considered when patients present with night blindness, impaired vision, and hypogonadotropic hypogonadism. Gene sequencing is currently the primary diagnostic method. Herein, novel compound heterozygous variants of PNPLA6 were identified in a BNS patient, and its function was verified at the RNA level. The PNPLA6 c.2241del variant is novel and potentially pathogenic, expanding the mutation spectrum in PNPLA6.
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Affiliation(s)
- Junyu He
- Department of Endocrinology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Xin Liu
- Aegicare Technology Co., Ltd., Shenzhen, China
| | - Liyi Liu
- Department of Endocrinology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Shaohao Zeng
- Department of Endocrinology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Shuanghong Shan
- Department of Endocrinology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Zhihong Liao
- Department of Endocrinology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
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The Genetics of Pediatric Cutaneous Autoimmunity: The Sister Diseases Vitiligo and Alopecia Areata. Clin Dermatol 2022; 40:363-373. [DOI: 10.1016/j.clindermatol.2022.02.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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16
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Nanetti L, Di Bella D, Magri S, Fichera M, Sarto E, Castaldo A, Mongelli A, Baratta S, Fenu S, Moscatelli M, Bonati MT, Martinuzzi A, Mariotti C, Taroni F. Multifaceted and Age-Dependent Phenotypes Associated With Biallelic PNPLA6 Gene Variants: Eight Novel Cases and Review of the Literature. Front Neurol 2022; 12:793547. [PMID: 35069422 PMCID: PMC8770815 DOI: 10.3389/fneur.2021.793547] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 12/02/2021] [Indexed: 12/11/2022] Open
Abstract
A wide spectrum of neurodegenerative diseases has been associated with pathogenic variants in the PNPLA6 (patatin-like phospholipase domain-containing protein 6) gene, including spastic paraplegia type 39, Gordon-Holmes, Boucher-Neuhauser, Oliver-Mc Farlane, and Laurence-Moon syndromes. These syndromes present variable and overlapping clinical symptoms, encompassing cerebellar ataxia, hypogonadotropic hypogonadism, chorioretinal dystrophy, spastic paraplegia, muscle wasting, peripheral neuropathy, and cognitive impairment. In the present study, we performed a wide genetic screening in 292 patients presenting with ataxia or spastic paraplegia using a probe-based customized gene panel, covering >200 genes associated with spinocerebellar diseases. We identified six novel and four recurrent PNPLA6 gene variants in eight patients (2.7%). Six patients presented an infantile or juvenile onset (age <18), and two patients had an adult onset. Cerebellar ataxia was observed in seven patients and spastic paraplegia in one patient. Progression of cerebellar symptoms was slow in all patients, who retained ambulation even after a mean disease duration of 15 years. Brain MRI showed cerebellar atrophy in 6/8 patients, more pronounced in superior and dorsal vermis lobules (I to VII). Additional clinical features included hypogonadotropic hypogonadism (5/8), growth hormone deficiency (2/8), peripheral axonal neuropathy (4/8), cognitive impairment (3/8), chorioretinal dystrophy (2/8), and bilateral vestibular areflexia with a reduced visual vestibule-ocular reflex (1/8). In accordance with previous studies, chorioretinal dystrophy was the most frequent presenting symptom in early onset patients, hypogonadotropic hypogonadism in juvenile onset cases, and cerebellar ataxia in adult patients. One patient had an initial clinical presentation compatible with Cerebellar Ataxia with Neuropathy and Vestibular Areflexia Syndrome (CANVAS), but no pathological expansions in the RFC1 gene. In conclusion, patients with PNPLA6 variants present a variable age of onset spanning from infancy to adulthood, and each clinical symptom has an age-dependent manifestation thus requiring a multi-systemic diagnostic approach. The description of patients presenting very late-onset cerebellar ataxia suggests that PNPLA6 genetic screening should also be considered in the diagnostic workout of adult cerebellar ataxia.
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Affiliation(s)
- Lorenzo Nanetti
- Unit of Medical Genetics and Neurogenetics, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Istituto Neurologico Carlo Besta, Milan, Italy
| | - Daniela Di Bella
- Unit of Medical Genetics and Neurogenetics, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Istituto Neurologico Carlo Besta, Milan, Italy
| | - Stefania Magri
- Unit of Medical Genetics and Neurogenetics, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Istituto Neurologico Carlo Besta, Milan, Italy
| | - Mario Fichera
- Unit of Medical Genetics and Neurogenetics, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Istituto Neurologico Carlo Besta, Milan, Italy
| | - Elisa Sarto
- Unit of Medical Genetics and Neurogenetics, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Istituto Neurologico Carlo Besta, Milan, Italy
| | - Anna Castaldo
- Unit of Medical Genetics and Neurogenetics, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Istituto Neurologico Carlo Besta, Milan, Italy
| | - Alessia Mongelli
- Unit of Medical Genetics and Neurogenetics, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Istituto Neurologico Carlo Besta, Milan, Italy
| | - Silvia Baratta
- Unit of Medical Genetics and Neurogenetics, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Istituto Neurologico Carlo Besta, Milan, Italy
| | - Silvia Fenu
- Unit of Rare Neurodegenerative and Neurometabolic Diseases, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Istituto Neurologico Carlo Besta, Milan, Italy
| | - Marco Moscatelli
- Unit of Neuroradiology, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Istituto Neurologico Carlo Besta, Milan, Italy
| | - Maria Teresa Bonati
- Unit of Medical Genetics, Institute for Maternal and Child Health Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Burlo Garofalo, Trieste, Italy
| | - Andrea Martinuzzi
- Conegliano Research Center, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Eugenio Medea, Conegliano, Italy
| | - Caterina Mariotti
- Unit of Medical Genetics and Neurogenetics, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Istituto Neurologico Carlo Besta, Milan, Italy
| | - Franco Taroni
- Unit of Medical Genetics and Neurogenetics, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Istituto Neurologico Carlo Besta, Milan, Italy
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Chung EJ, You E, Oh SH, Seo GH, Chung WY, Kim YJ, Kim SJ. The First Korean Family With Boucher-Neuhäuser Syndrome Carrying a Novel Mutation in PNPLA6. J Clin Neurol 2022; 18:233-234. [PMID: 35274841 PMCID: PMC8926775 DOI: 10.3988/jcn.2022.18.2.233] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 10/19/2021] [Accepted: 10/19/2021] [Indexed: 11/22/2022] Open
Affiliation(s)
- Eun Joo Chung
- Department of Neurology, Busan Paik Hospital, Inje University College of Medicine, Busan, Korea
- Dementia and Neurodegenerative Disease Research Center, Inje University, Gimhae, Korea
| | - Eunkyoung You
- Department of Laboratory Medicine, Busan Paik Hospital, Inje University College of Medicine, Busan, Korea
| | - Seung Hwan Oh
- Department of Laboratory Medicine, Pusan National University Yangsan Hospital, Yangsan, Korea
| | | | - Woo Yeong Chung
- Department of Pediatrics, Busan Paik Hospital, Inje University College of Medicine, Busan, Korea
- Rare Disease Busan Regional Center, Busan, Korea
| | - Yun Joong Kim
- Department of Neurology, Yongin Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Sang Jin Kim
- Department of Neurology, Busan Paik Hospital, Inje University College of Medicine, Busan, Korea
- Dementia and Neurodegenerative Disease Research Center, Inje University, Gimhae, Korea
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Drosophila Lysophospholipase Gene swiss cheese Is Required for Survival and Reproduction. INSECTS 2021; 13:insects13010014. [PMID: 35055857 PMCID: PMC8781823 DOI: 10.3390/insects13010014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 12/15/2021] [Accepted: 12/17/2021] [Indexed: 12/28/2022]
Abstract
Simple Summary Biological evolution implies fitness of newly evolved organisms that have inherent adaptive traits because of mutations in genes. However, most mutations are detrimental, and they spoil the organism’s life, its survival and its ability to leave progeny. Some genes are extremely vital for an organism, and therefore, they tend to save their structure and do not mutate or do it very composedly. That is the case of the gene encoding PNPLA6 lysophospholipase domain that evolved in bacteria, and evolution obliged it to save its function in higher animals. In mammals, complete dysfunction of such a gene is lethal because of its high importance in placenta for early embryo development. Why is it conserved in other species, for instance insects, that have no placenta? Here we studied the role of the PNPLA6-encoding gene named swiss cheese in Drosophila melanogaster fitness. We have found that its dysfunction results in premature death of specimens and their inability to leave enough progeny. Thus, we provide the first evidence for significance of the gene that encodes the lysophospholipase enzyme in fitness of insects. Abstract Drosophila melanogaster is one of the most famous insects in biological research. It is widely used to analyse functions of different genes. The phosphatidylcholine lysophospholipase gene swiss cheese was initially shown to be important in the fruit fly nervous system. However, the role of this gene in non-nervous cell types has not been elucidated yet, and the evolutional explanation for the conservation of its function remains elusive. In this study, we analyse expression pattern and some aspects of the role of the swiss cheese gene in the fitness of Drosophila melanogaster. We describe the spatiotemporal expression of swiss cheese throughout the fly development and analyse the survival and productivity of swiss cheese mutants. We found swiss cheese to be expressed in salivary glands, midgut, Malpighian tubes, adipocytes, and male reproductive system. Dysfunction of swiss cheese results in severe pupae and imago lethality and decline of fertility, which is impressive in males. The latter is accompanied with abnormalities of male locomotor activity and courtship behaviour, accumulation of lipid droplets in testis cyst cells and decrease in spermatozoa motility. These results suggest that normal swiss cheese is important for Drosophila melanogaster fitness due to its necessity for both specimen survival and their reproductive success.
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Whittaker DE, Oleari R, Gregory LC, Le Quesne-Stabej P, Williams HJ, Torpiano JG, Formosa N, Cachia MJ, Field D, Lettieri A, Ocaka LA, Paganoni AJ, Rajabali SH, Riegman KL, De Martini LB, Chaya T, Robinson IC, Furukawa T, Cariboni A, Basson MA, Dattani MT. A recessive PRDM13 mutation results in congenital hypogonadotropic hypogonadism and cerebellar hypoplasia. J Clin Invest 2021; 131:e141587. [PMID: 34730112 PMCID: PMC8670848 DOI: 10.1172/jci141587] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 10/27/2021] [Indexed: 11/17/2022] Open
Abstract
The positive regulatory (PR) domain containing 13 (PRDM13) putative chromatin modifier and transcriptional regulator functions downstream of the transcription factor PTF1A, which controls GABAergic fate in the spinal cord and neurogenesis in the hypothalamus. Here, we report a recessive syndrome associated with PRDM13 mutation. Patients exhibited intellectual disability, ataxia with cerebellar hypoplasia, scoliosis, and delayed puberty with congenital hypogonadotropic hypogonadism (CHH). Expression studies revealed Prdm13/PRDM13 transcripts in the developing hypothalamus and cerebellum in mouse and human. An analysis of hypothalamus and cerebellum development in mice homozygous for a Prdm13 mutant allele revealed a significant reduction in the number of Kisspeptin (Kiss1) neurons in the hypothalamus and PAX2+ progenitors emerging from the cerebellar ventricular zone. The latter was accompanied by ectopic expression of the glutamatergic lineage marker TLX3. Prdm13-deficient mice displayed cerebellar hypoplasia and normal gonadal structure, but delayed pubertal onset. Together, these findings identify PRDM13 as a critical regulator of GABAergic cell fate in the cerebellum and of hypothalamic kisspeptin neuron development, providing a mechanistic explanation for the cooccurrence of CHH and cerebellar hypoplasia in this syndrome. To our knowledge, this is the first evidence linking disrupted PRDM13-mediated regulation of Kiss1 neurons to CHH in humans.
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Affiliation(s)
- Danielle E. Whittaker
- Centre for Craniofacial and Regenerative Biology, King’s College London, London, United Kingdom
- Department of Comparative Biomedical Sciences, Royal Veterinary College, London, United Kingdom
| | - Roberto Oleari
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy
| | - Louise C. Gregory
- Section of Molecular Basis of Rare Disease, Genetics and Genomic Medicine Research and Teaching Department, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
| | - Polona Le Quesne-Stabej
- Section of Molecular Basis of Rare Disease, Genetics and Genomic Medicine Research and Teaching Department, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
| | - Hywel J. Williams
- Section of Molecular Basis of Rare Disease, Genetics and Genomic Medicine Research and Teaching Department, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
| | - GOSgene
- Section of Molecular Basis of Rare Disease, Genetics and Genomic Medicine Research and Teaching Department, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
- GOSgene is detailed in Supplemental Acknowledgments
| | - John G. Torpiano
- Department of Paediatrics and
- Adult Endocrinology Service, Mater Dei Hospital, Msida, Malta
| | | | - Mario J. Cachia
- Adult Endocrinology Service, Mater Dei Hospital, Msida, Malta
| | - Daniel Field
- Centre for Craniofacial and Regenerative Biology, King’s College London, London, United Kingdom
| | - Antonella Lettieri
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy
| | - Louise A. Ocaka
- Section of Molecular Basis of Rare Disease, Genetics and Genomic Medicine Research and Teaching Department, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
| | - Alyssa J.J. Paganoni
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy
| | - Sakina H. Rajabali
- Centre for Craniofacial and Regenerative Biology, King’s College London, London, United Kingdom
| | - Kimberley L.H. Riegman
- Centre for Craniofacial and Regenerative Biology, King’s College London, London, United Kingdom
| | - Lisa B. De Martini
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy
| | - Taro Chaya
- Laboratory for Molecular and Developmental Biology, Institute for Protein Research, Osaka University, Osaka, Japan
| | | | - Takahisa Furukawa
- Laboratory for Molecular and Developmental Biology, Institute for Protein Research, Osaka University, Osaka, Japan
| | - Anna Cariboni
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy
| | - M. Albert Basson
- Centre for Craniofacial and Regenerative Biology, King’s College London, London, United Kingdom
- MRC Centre for Neurodevelopmental Disorders, King’s College London, London, United Kingdom
| | - Mehul T. Dattani
- Section of Molecular Basis of Rare Disease, Genetics and Genomic Medicine Research and Teaching Department, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
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Melentev PA, Ryabova EV, Sarantseva SV. A Private History of Neurogenetics: The swiss cheese Gene and Its Orthologs. RUSS J GENET+ 2021. [DOI: 10.1134/s1022795421090076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Hage C, Gan HW, Ibba A, Patti G, Dattani M, Loche S, Maghnie M, Salvatori R. Advances in differential diagnosis and management of growth hormone deficiency in children. Nat Rev Endocrinol 2021; 17:608-624. [PMID: 34417587 DOI: 10.1038/s41574-021-00539-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/06/2021] [Indexed: 02/07/2023]
Abstract
Growth hormone (GH) deficiency (GHD) in children is defined as impaired production of GH by the pituitary gland that results in growth failure. This disease might be congenital or acquired, and occurs in isolation or in the setting of multiple pituitary hormone deficiency. Isolated GHD has an estimated prevalence of 1 patient per 4000-10,000 live births and can be due to multiple causes, some of which are yet to be determined. Establishing the correct diagnosis remains key in children with short stature, as initiating treatment with recombinant human GH can help them attain their genetically determined adult height. During the past two decades, our understanding of the benefits of continuing GH therapy throughout the transition period from childhood to adulthood has increased. Improvements in transitional care will help alleviate the consequent physical and psychological problems that can arise from adult GHD, although the consequences of a lack of hormone replacement are less severe in adults than in children. In this Review, we discuss the differential diagnosis in children with GHD, including details of clinical presentation, neuroimaging and genetic testing. Furthermore, we highlight advances and issues in the management of GHD, including details of transitional care.
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Affiliation(s)
- Camille Hage
- Division of Endocrinology, Diabetes, & Metabolism, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Hoong-Wei Gan
- Genetics & Genomic Medicine Research and Teaching Department, University College London Great Ormond Street Hospital Institute of Child Health, London, UK
- Department of Paediatric Endocrinology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Anastasia Ibba
- Paediatric Endocrine Unit, Paediatric Hospital Microcitemico "A. Cao", AO Brotzu, Cagliari, Italy
| | - Giuseppa Patti
- Department of Paediatrics, IRCCS Istituto Giannina Gaslini, Genova, Italy
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genova, Genova, Italy
| | - Mehul Dattani
- Genetics & Genomic Medicine Research and Teaching Department, University College London Great Ormond Street Hospital Institute of Child Health, London, UK
- Department of Paediatric Endocrinology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Sandro Loche
- Paediatric Endocrine Unit, Paediatric Hospital Microcitemico "A. Cao", AO Brotzu, Cagliari, Italy
| | - Mohamad Maghnie
- Department of Paediatrics, IRCCS Istituto Giannina Gaslini, Genova, Italy
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genova, Genova, Italy
| | - Roberto Salvatori
- Division of Endocrinology, Diabetes, & Metabolism, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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22
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NGS in Hereditary Ataxia: When Rare Becomes Frequent. Int J Mol Sci 2021; 22:ijms22168490. [PMID: 34445196 PMCID: PMC8395181 DOI: 10.3390/ijms22168490] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 08/03/2021] [Accepted: 08/04/2021] [Indexed: 12/17/2022] Open
Abstract
The term hereditary ataxia (HA) refers to a heterogeneous group of neurological disorders with multiple genetic etiologies and a wide spectrum of ataxia-dominated phenotypes. Massive gene analysis in next-generation sequencing has entered the HA scenario, broadening our genetic and clinical knowledge of these conditions. In this study, we employed a targeted resequencing panel (TRP) in a large and highly heterogeneous cohort of 377 patients with a clinical diagnosis of HA, but no molecular diagnosis on routine genetic tests. We obtained a positive result (genetic diagnosis) in 33.2% of the patients, a rate significantly higher than those reported in similar studies employing TRP (average 19.4%), and in line with those performed using exome sequencing (ES, average 34.6%). Moreover, 15.6% of the patients had an uncertain molecular diagnosis. STUB1, PRKCG, and SPG7 were the most common causative genes. A comparison with published literature data showed that our panel would have identified 97% of the positive cases reported in previous TRP-based studies and 92% of those diagnosed by ES. Proper use of multigene panels, when combined with detailed phenotypic data, seems to be even more efficient than ES in clinical practice.
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23
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Melentev PA, Ryabova EV, Surina NV, Zhmujdina DR, Komissarov AE, Ivanova EA, Boltneva NP, Makhaeva GF, Sliusarenko MI, Yatsenko AS, Mohylyak II, Matiytsiv NP, Shcherbata HR, Sarantseva SV. Loss of swiss cheese in Neurons Contributes to Neurodegeneration with Mitochondria Abnormalities, Reactive Oxygen Species Acceleration and Accumulation of Lipid Droplets in Drosophila Brain. Int J Mol Sci 2021; 22:8275. [PMID: 34361042 PMCID: PMC8347196 DOI: 10.3390/ijms22158275] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 07/23/2021] [Accepted: 07/27/2021] [Indexed: 12/17/2022] Open
Abstract
Various neurodegenerative disorders are associated with human NTE/PNPLA6 dysfunction. Mechanisms of neuropathogenesis in these diseases are far from clearly elucidated. Hereditary spastic paraplegia belongs to a type of neurodegeneration associated with NTE/PNLPLA6 and is implicated in neuron death. In this study, we used Drosophila melanogaster to investigate the consequences of neuronal knockdown of swiss cheese (sws)-the evolutionarily conserved ortholog of human NTE/PNPLA6-in vivo. Adult flies with the knockdown show longevity decline, locomotor and memory deficits, severe neurodegeneration progression in the brain, reactive oxygen species level acceleration, mitochondria abnormalities and lipid droplet accumulation. Our results suggest that SWS/NTE/PNPLA6 dysfunction in neurons induces oxidative stress and lipid metabolism alterations, involving mitochondria dynamics and lipid droplet turnover in neurodegeneration pathogenesis. We propose that there is a complex mechanism in neurological diseases such as hereditary spastic paraplegia, which includes a stress reaction, engaging mitochondria, lipid droplets and endoplasmic reticulum interplay.
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Affiliation(s)
- Pavel A. Melentev
- Petersburg Nuclear Physics Institute Named by B.P. Konstantinov of NRC «Kurchatov Institute», 188300 Gatchina, Russia; (P.A.M.); (E.V.R.); (N.V.S.); (D.R.Z.); (A.E.K.); (E.A.I.)
| | - Elena V. Ryabova
- Petersburg Nuclear Physics Institute Named by B.P. Konstantinov of NRC «Kurchatov Institute», 188300 Gatchina, Russia; (P.A.M.); (E.V.R.); (N.V.S.); (D.R.Z.); (A.E.K.); (E.A.I.)
| | - Nina V. Surina
- Petersburg Nuclear Physics Institute Named by B.P. Konstantinov of NRC «Kurchatov Institute», 188300 Gatchina, Russia; (P.A.M.); (E.V.R.); (N.V.S.); (D.R.Z.); (A.E.K.); (E.A.I.)
| | - Darya R. Zhmujdina
- Petersburg Nuclear Physics Institute Named by B.P. Konstantinov of NRC «Kurchatov Institute», 188300 Gatchina, Russia; (P.A.M.); (E.V.R.); (N.V.S.); (D.R.Z.); (A.E.K.); (E.A.I.)
| | - Artem E. Komissarov
- Petersburg Nuclear Physics Institute Named by B.P. Konstantinov of NRC «Kurchatov Institute», 188300 Gatchina, Russia; (P.A.M.); (E.V.R.); (N.V.S.); (D.R.Z.); (A.E.K.); (E.A.I.)
| | - Ekaterina A. Ivanova
- Petersburg Nuclear Physics Institute Named by B.P. Konstantinov of NRC «Kurchatov Institute», 188300 Gatchina, Russia; (P.A.M.); (E.V.R.); (N.V.S.); (D.R.Z.); (A.E.K.); (E.A.I.)
| | - Natalia P. Boltneva
- Institute of Physiologically Active Compounds Russian Academy of Sciences, 142432 Chernogolovka, Russia; (N.P.B.); (G.F.M.)
| | - Galina F. Makhaeva
- Institute of Physiologically Active Compounds Russian Academy of Sciences, 142432 Chernogolovka, Russia; (N.P.B.); (G.F.M.)
| | - Mariana I. Sliusarenko
- Institute of Cell Biochemistry, Hannover Medical School, 30625 Hannover, Germany; (M.I.S.); (A.S.Y.); (H.R.S.)
| | - Andriy S. Yatsenko
- Institute of Cell Biochemistry, Hannover Medical School, 30625 Hannover, Germany; (M.I.S.); (A.S.Y.); (H.R.S.)
| | - Iryna I. Mohylyak
- Department of Genetics and Biotechnology, Ivan Franko National University of Lviv, 79005 Lviv, Ukraine; (I.I.M.); (N.P.M.)
| | - Nataliya P. Matiytsiv
- Department of Genetics and Biotechnology, Ivan Franko National University of Lviv, 79005 Lviv, Ukraine; (I.I.M.); (N.P.M.)
| | - Halyna R. Shcherbata
- Institute of Cell Biochemistry, Hannover Medical School, 30625 Hannover, Germany; (M.I.S.); (A.S.Y.); (H.R.S.)
| | - Svetlana V. Sarantseva
- Petersburg Nuclear Physics Institute Named by B.P. Konstantinov of NRC «Kurchatov Institute», 188300 Gatchina, Russia; (P.A.M.); (E.V.R.); (N.V.S.); (D.R.Z.); (A.E.K.); (E.A.I.)
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Buch J, Ranganath P. Approach to inherited hypertrichosis: A brief review. Indian J Dermatol Venereol Leprol 2021; 88:11-21. [PMID: 34379956 DOI: 10.25259/ijdvl_629_20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 12/01/2020] [Indexed: 11/04/2022]
Abstract
Hypertrichosis refers to the growth of hair, of an excessive amount and thickness, on any part of the body. It must be distinguished from hirsutism which is characterized by excess growth of hair in androgen-dependent areas on the upper lip, chin, chest, linea alba, thigh and axilla. Hypertrichosis may be localized or generalized, and congenital or acquired. Excess hair growth has a psychological impact on the child as well as the parents due to the cosmetic disfigurement it produces. Current treatment options are limited and not wholly satisfactory. Treatment should be customized according to the area, nature and amount of hair growth, age of the patient and personal preferences. In addition, when hypertrichosis occurs as a component of a syndrome, multidisciplinary management is required to address the associated systemic features. A detailed review of inherited generalized hypertrichosis is presented here with emphasis on clinical clues to identifying complex syndromes with multisystem involvement.
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Affiliation(s)
- Jeta Buch
- Dermaclinix - The Complete Skin and Hair Solution Centre, New Delhi, India
| | - Prajnya Ranganath
- Department of Medical Genetics, Nizam's Institute of Medical Sciences, Hyderabad, Telangana, India
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25
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Vishnopolska SA, Mercogliano MF, Camilletti MA, Mortensen AH, Braslavsky D, Keselman A, Bergadá I, Olivieri F, Miranda L, Marino R, Ramírez P, Pérez Garrido N, Patiño Mejia H, Ciaccio M, Di Palma MI, Belgorosky A, Martí MA, Kitzman JO, Camper SA, Pérez-Millán MI. Comprehensive Identification of Pathogenic Gene Variants in Patients With Neuroendocrine Disorders. J Clin Endocrinol Metab 2021; 106:1956-1976. [PMID: 33729509 PMCID: PMC8208670 DOI: 10.1210/clinem/dgab177] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 02/12/2021] [Indexed: 02/03/2023]
Abstract
PURPOSE Congenital hypopituitarism (CH) can present in isolation or with other birth defects. Mutations in multiple genes can cause CH, and the use of a genetic screening panel could establish the prevalence of mutations in known and candidate genes for this disorder. It could also increase the proportion of patients that receive a genetic diagnosis. METHODS We conducted target panel genetic screening using single-molecule molecular inversion probes sequencing to assess the frequency of mutations in known hypopituitarism genes and new candidates in Argentina. We captured genomic deoxyribonucleic acid from 170 pediatric patients with CH, either alone or with other abnormalities. We performed promoter activation assays to test the functional effects of patient variants in LHX3 and LHX4. RESULTS We found variants classified as pathogenic, likely pathogenic, or with uncertain significance in 15.3% of cases. These variants were identified in known CH causative genes (LHX3, LHX4, GLI2, OTX2, HESX1), in less frequently reported genes (FOXA2, BMP4, FGFR1, PROKR2, PNPLA6) and in new candidate genes (BMP2, HMGA2, HNF1A, NKX2-1). CONCLUSION In this work, we report the prevalence of mutations in known CH genes in Argentina and provide evidence for new candidate genes. We show that CH is a genetically heterogeneous disease with high phenotypic variation and incomplete penetrance, and our results support the need for further gene discovery for CH. Identifying population-specific pathogenic variants will improve the capacity of genetic data to predict eventual clinical outcomes.
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Affiliation(s)
- Sebastian Alexis Vishnopolska
- Instituto de Biociencias, Biotecnología y Biología Traslacional (IB3), Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad de Buenos Aires,Argentina
- Instituto de Química Biología en Exactas y Naturales (IQUIBICEN-CONICET), Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad de Buenos Aires,Argentina
| | - Maria Florencia Mercogliano
- Instituto de Química Biología en Exactas y Naturales (IQUIBICEN-CONICET), Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad de Buenos Aires,Argentina
| | - Maria Andrea Camilletti
- Instituto de Biociencias, Biotecnología y Biología Traslacional (IB3), Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad de Buenos Aires,Argentina
- Instituto de Química Biología en Exactas y Naturales (IQUIBICEN-CONICET), Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad de Buenos Aires,Argentina
| | - Amanda Helen Mortensen
- Deptartment of Human Genetics, University of Michigan Medical School, Ann Arbor, MI 48198-5618, USA
| | - Debora Braslavsky
- Centro de Investigaciones Endocrinológicas “Dr. César Bergadá,” (CEDIE), FEI – CONICET – División de Endocrinología, Hospital de Niños Ricardo Gutiérrez, Ciudad de Buenos Aires, C1425EFD, Argentina
| | - Ana Keselman
- Centro de Investigaciones Endocrinológicas “Dr. César Bergadá,” (CEDIE), FEI – CONICET – División de Endocrinología, Hospital de Niños Ricardo Gutiérrez, Ciudad de Buenos Aires, C1425EFD, Argentina
| | - Ignacio Bergadá
- Centro de Investigaciones Endocrinológicas “Dr. César Bergadá,” (CEDIE), FEI – CONICET – División de Endocrinología, Hospital de Niños Ricardo Gutiérrez, Ciudad de Buenos Aires, C1425EFD, Argentina
| | - Federico Olivieri
- Instituto de Química Biología en Exactas y Naturales (IQUIBICEN-CONICET), Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad de Buenos Aires,Argentina
| | - Lucas Miranda
- Instituto de Química Biología en Exactas y Naturales (IQUIBICEN-CONICET), Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad de Buenos Aires,Argentina
| | - Roxana Marino
- Servicio de Endocrinología, Hospital Garrahan, Ciudad de Buenos Aires, C1245, Argentina
| | - Pablo Ramírez
- Servicio de Endocrinología, Hospital Garrahan, Ciudad de Buenos Aires, C1245, Argentina
| | - Natalia Pérez Garrido
- Servicio de Endocrinología, Hospital Garrahan, Ciudad de Buenos Aires, C1245, Argentina
| | - Helen Patiño Mejia
- Servicio de Endocrinología, Hospital Garrahan, Ciudad de Buenos Aires, C1245, Argentina
| | - Marta Ciaccio
- Servicio de Endocrinología, Hospital Garrahan, Ciudad de Buenos Aires, C1245, Argentina
| | - Maria Isabel Di Palma
- Servicio de Endocrinología, Hospital Garrahan, Ciudad de Buenos Aires, C1245, Argentina
| | - Alicia Belgorosky
- Hospital de Pediatría Garrahan-CONICET, Ciudad de Buenos Aires, Argentina
| | - Marcelo Adrian Martí
- Instituto de Química Biología en Exactas y Naturales (IQUIBICEN-CONICET), Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad de Buenos Aires,Argentina
| | - Jacob Otto Kitzman
- Deptartment of Human Genetics, University of Michigan Medical School, Ann Arbor, MI 48198-5618, USA
| | - Sally Ann Camper
- Deptartment of Human Genetics, University of Michigan Medical School, Ann Arbor, MI 48198-5618, USA
- Correspondence: Sally A. Camper, PhD, University of Michigan Medical School, Ann Arbor, MI 48198-5618, United States. E-mail: ; or Maria Ines Perez-Millan, PhD, University of Buenos Aires, Buenos Aires, C1428EHA, Argentina. E-mail:
| | - Maria Ines Pérez-Millán
- Instituto de Biociencias, Biotecnología y Biología Traslacional (IB3), Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad de Buenos Aires,Argentina
- Correspondence: Sally A. Camper, PhD, University of Michigan Medical School, Ann Arbor, MI 48198-5618, United States. E-mail: ; or Maria Ines Perez-Millan, PhD, University of Buenos Aires, Buenos Aires, C1428EHA, Argentina. E-mail:
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26
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Zebrafish Models of Autosomal Recessive Ataxias. Cells 2021; 10:cells10040836. [PMID: 33917666 PMCID: PMC8068028 DOI: 10.3390/cells10040836] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 04/01/2021] [Accepted: 04/06/2021] [Indexed: 12/11/2022] Open
Abstract
Autosomal recessive ataxias are much less well studied than autosomal dominant ataxias and there are no clearly defined systems to classify them. Autosomal recessive ataxias, which are characterized by neuronal and multisystemic features, have significant overlapping symptoms with other complex multisystemic recessive disorders. The generation of animal models of neurodegenerative disorders increases our knowledge of their cellular and molecular mechanisms and helps in the search for new therapies. Among animal models, the zebrafish, which shares 70% of its genome with humans, offer the advantages of being small in size and demonstrating rapid development, making them optimal for high throughput drug and genetic screening. Furthermore, embryo and larval transparency allows to visualize cellular processes and central nervous system development in vivo. In this review, we discuss the contributions of zebrafish models to the study of autosomal recessive ataxias characteristic phenotypes, behavior, and gene function, in addition to commenting on possible treatments found in these models. Most of the zebrafish models generated to date recapitulate the main features of recessive ataxias.
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27
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Lisbjerg K, Andersen MKG, Bertelsen M, Brost AG, Buchvald FF, Jensen RB, Bisgaard AM, Rosenberg T, Tümer Z, Kessel L. Oliver McFarlane syndrome: two new cases and a review of the literature. Ophthalmic Genet 2021; 42:464-473. [PMID: 33818269 DOI: 10.1080/13816810.2021.1904419] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
BACKGROUND Oliver McFarlane syndrome is a rare syndrome. Clinical presentations include trichomegaly, chorioretinal degeneration, pituitary hormone deficits, and neurological manifestations. Genetic analysis has recently placed this syndrome within the group of PNPLA6-related disorders. Here, we describe two new individuals and review the previously published cases. MATERIALS AND METHODS Clinical investigations were carried out in accordance with local guidelines and clinical information was retrieved from medical records. Genetic studies were carried out using next-generation sequencing based clinical exome sequencing. A PubMed literature search was performed with a review of the published clinical cases of Oliver McFarlane syndrome. RESULTS Our first individual was a 36-year-old woman with 32 years of follow up and our second individual was a 3-year-old boy. Both individuals were born preterm and presented with prolonged neonatal respiratory distress, trichomegaly, early growth retardation, retinopathy and sparse depigmented hair. So far, none of our cases have demonstrated cognitive impairment or progressive neurological symptoms, but the child revealed persistent abnormal lung structure. Both individuals were compound heterozygous for pathogenic PNPLA6 variants, one of which was novel. We found other 31 clinically documented published cases. CONCLUSIONS Our two new unrelated cases of Oliver McFarlane Syndrome demonstrate early ophthalmological and systemic findings of this rare syndrome and the progressive nature of the retinopathy with a long follow-up. PNPLA6-related disorders are a phenotypically highly heterogenous group where alterations in the phosphatidylcholine metabolism can lead to manifestations in different tissues with no clear genotype-phenotype correlation.
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Affiliation(s)
- Kristian Lisbjerg
- Department of Ophthalmology, Copenhagen University Hospital, Rigshospitalet , Copenhagen, Denmark
| | - Mette K G Andersen
- Department of Ophthalmology, Copenhagen University Hospital, Rigshospitalet , Copenhagen, Denmark
| | - Mette Bertelsen
- Department of Clinical Genetics, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Agnes G Brost
- Department of Ophthalmology, Copenhagen University Hospital, Rigshospitalet , Copenhagen, Denmark
| | - Frederik F Buchvald
- Center for Pulmonary Diseases, Department of Pediatrics and Adolescent Medicine, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Rikke B Jensen
- Department of Growth and Reproduction, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Anne-Marie Bisgaard
- Center for Rare Diseases, Department of Pediatrics and Adolescent Medicine, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Thomas Rosenberg
- Department of Ophthalmology, Copenhagen University Hospital, Rigshospitalet , Copenhagen, Denmark
| | - Zeynep Tümer
- Department of Clinical Genetics, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.,Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Line Kessel
- Department of Ophthalmology, Copenhagen University Hospital, Rigshospitalet , Copenhagen, Denmark.,Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
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Doğan M, Eröz R, Öztürk E. Chorioretinal dystrophy, hypogonadotropic hypogonadism, and cerebellar ataxia: Boucher-Neuhauser syndrome due to a homozygous (c.3524C>G (p.Ser1175Cys)) variant in PNPLA6 gene. Ophthalmic Genet 2021; 42:276-282. [PMID: 33650466 DOI: 10.1080/13816810.2021.1894461] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Purpose: The current study aims to raise awareness of Boucher - Neuhauser syndrome (BNHS) that occurs as a rare phenotype due to biallelic pathogenic variants in the PNPLA6 gene.Methods: Detailed family histories and clinical data were recorded. Whole exome sequencing was performed and co-segregation analysis of the family was done by sanger sequencing. Also, review of 28 molecularly confirmed patients with BNHS from the literature was evaluated.Results: We identified a missense homozygous variant (c.3524 C > G (p.Ser1175Cys)) in the PNPLA6 gene, which explains the phenotype of the patient and neurologic, ophthalmologic, endocrine, and genetic evaluations established a diagnosis of BNHS. Symptoms, ethnicity, clinical and genetic findings of 28 molecularly confirmed patients with BNHS from the literature were also presented.Conclusion: We present the main findings of a Turkish family with BNHS together with detailed clinical and genetic profiles of patients diagnosed as BNHS that have been molecularly confirmed in the literature so far.
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Affiliation(s)
- Mustafa Doğan
- Department of Medical Genetics, Malatya Turgut Özal University Medical Faculty, Malatya, Turkey
| | - Recep Eröz
- Department of Medical Genetics, Duzce University Medical Faculty, Duzce, Turkey
| | - Emrah Öztürk
- Department of Ophthalmology, Malatya Training and Research Hospital, Malatya, Turkey
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29
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Wang P, Wu YJ, Sun ML. Decrease of an intracellular organic osmolyte contributes to the cytotoxicity of organophosphate in neuroblastoma cells in vitro. Toxicology 2021; 453:152725. [PMID: 33617914 DOI: 10.1016/j.tox.2021.152725] [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: 08/11/2020] [Revised: 02/06/2021] [Accepted: 02/13/2021] [Indexed: 11/29/2022]
Abstract
Organophosphorus compounds (OP) causes prominent delayed neuropathy in vivo and cytotoxicity to neuronal cells in vitro. The primary target protein of OP's neurotoxicity is neuropathy target esterase (NTE), which can convert phosphatidylcholine (PC) to glycerophosphocholine (GPC). Recent studies reveal that autophagic cell death is important for the initiation and progression of OP-induced neurotoxicity both in vivo and in vitro. However, the mechanism of how OP induces autophagic cell death is unknown. Here it is found that GPC is an important organic osmolyte in the neuroblastoma cells, and treatment with tri-o-cresyl phosphate (TOCP), a representative OP, leads to the decrease of GPC and imbalance of extracellular and intracellular osmolality. Knockdown of GPC metabolizing enzyme glycerophosphodiester phosphodiesterase domain containing 5 (GDPD5) reverses TOCP-induced autophagic cell death, which further supports the notion that the reduced GPC level leads to the autophagic cell death. Furthermore, it is found that autophagic cell death is due to the induction of reactive oxygen species (ROS) and mitochondrial damage by imbalance of osmolality with TOCP treatment. In summary, this study reveals that TOCP treatment decreases GPC level and intracellular osmolality, which induces ROS and mitochondrial damage and leads to the cell death and neurite degradation by autophagy. This study lays the foundation for further investigations on the potential therapeutic approaches for OP neurotoxicity or NTE mutation-related neurological diseases.
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Affiliation(s)
- Pan Wang
- Laboratory of Molecular Toxicology, State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, 1-5 Beichenxilu Road, Beijing, 100101, China; School of Life and Health Sciences, The Chinese University of Hong Kong, Shenzhen, Guangdong, 518172, China
| | - Yi-Jun Wu
- Laboratory of Molecular Toxicology, State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, 1-5 Beichenxilu Road, Beijing, 100101, China.
| | - Man-Lian Sun
- Laboratory of Molecular Toxicology, State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, 1-5 Beichenxilu Road, Beijing, 100101, China
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30
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Emekli AS, Samanci B, Şimşir G, Hanagasi HA, Gürvit H, Bilgiç B, Başak AN. A novel PNPLA6 mutation in a Turkish family with intractable Holmes tremor and spastic ataxia. Neurol Sci 2020; 42:1535-1539. [PMID: 33210227 DOI: 10.1007/s10072-020-04869-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 10/28/2020] [Indexed: 10/23/2022]
Abstract
Autosomal recessive cerebellar ataxias are a group of rare neurological diseases with a genetic origin. Recently, the mutations in the PNPLA6 gene were suggested to lead to ataxia and also to other specific syndromes such as Boucher-Neuhauser (ataxia, hypogonadism, and chorioretinal dystrophy) or Gordon-Holmes Syndromes (ataxia, hypogonadism, and brisk reflexes) within a broad spectrum of neurodegenerative diseases. Here we report three patients from a single-family with a novel pathogenic mutation in the PNPLA6 gene which led to predominantly spastic-ataxia, and intractable Holmes tremor. The PNPLA6-related disease should be considered in the differential diagnosis of spastic-ataxias even in the absence of chorioretinal dystrophy, and hypogonadotropic hypogonadism. Further studies should unravel the factors which account for the phenotypic variability present in patients with PNPLA6 gene mutations.
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Affiliation(s)
- Ahmed S Emekli
- Behavioral Neurology and Movement Disorders Unit, Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, 34093, Istanbul, Turkey.
| | - Bedia Samanci
- Behavioral Neurology and Movement Disorders Unit, Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, 34093, Istanbul, Turkey
| | - Gülşah Şimşir
- Suna and İnan Kıraç Foundation, Neurodegeneration Research Laboratory, KUTTAM, Koç University, School of Medicine, Istanbul, Turkey
| | - Hasmet A Hanagasi
- Behavioral Neurology and Movement Disorders Unit, Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, 34093, Istanbul, Turkey
| | - Hakan Gürvit
- Behavioral Neurology and Movement Disorders Unit, Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, 34093, Istanbul, Turkey
| | - Başar Bilgiç
- Behavioral Neurology and Movement Disorders Unit, Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, 34093, Istanbul, Turkey
| | - A Nazlı Başak
- Suna and İnan Kıraç Foundation, Neurodegeneration Research Laboratory, KUTTAM, Koç University, School of Medicine, Istanbul, Turkey
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31
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Identification of Oliver-McFarlane syndrome caused by novel compound heterozygous variants of PNPLA6. Gene 2020; 761:145027. [DOI: 10.1016/j.gene.2020.145027] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 07/16/2020] [Accepted: 08/01/2020] [Indexed: 02/07/2023]
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Wu S, Sun Z, Zhu T, Weleber RG, Yang P, Wei X, Pennesi ME, Sui R. Novel variants in PNPLA6 causing syndromic retinal dystrophy. Exp Eye Res 2020; 202:108327. [PMID: 33141049 DOI: 10.1016/j.exer.2020.108327] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 10/15/2020] [Accepted: 10/20/2020] [Indexed: 12/18/2022]
Abstract
PNPLA6-related disorders include several phenotypes, such as Boucher-Neuhäuser syndrome, Gordon Holmes syndrome, spastic paraplegia, photoreceptor degeneration, Oliver-McFarlane syndrome and Laurence-Moon syndrome. In this study, detailed clinical evaluations and genetic testing were performed in five (4 Chinese and 1 Caucasian/Chinese) syndromic retinal dystrophy patients. Genotype-phenotype correlations were analyzed based on review of the literatures of previously published PNPLA6-related cases. The mean age of patients and at first visit were 20.8 years (11, 12, 25, 28, 28) and 14.2 years (4, 7, 11, 24, 25), respectively. They all presented with severe chorioretinal dystrophy and profoundly decreased vision. The best corrected visual acuity (BCVA) ranged from 20/200 to 20/2000. Systemic manifestations included cerebellar ataxia, hypogonadotropic hypogonadism and hair anomalies. Six novel and three reported pathogenic variants in PNPLA6 (NM_001166111) were identified. The genotypes of the five cases are: c.3134C > T (p.Ser1045Leu) and c.3846+1G > A, c.3547C > T (p.Arg1183Trp) and c.1841+3A > G, c.3436G > A (p.Ala1146Thr) and c.2212-10A > G, c.3436G > A (p.Ala1146Thr) and c.2266C > T (p.Gln756*), c.1238_1239insC (p.Leu414Serfs*28) and c.3130A > G (p.Thr1044Ala). RT-PCR confirmed that the splicing variants indeed led to abnormal splicing. Missense variants p.Thr1044Ala, p.Ser1045Leu, p.Ala1146Thr, p.Arg1183Trp and c.3846+1G > A are located in Patatin-like phospholipase (Pat) domain. In conclusion, we report the phenotypes in five patients with PNPLA6 associated syndromic retinal dystrophy with variable systemic involvement and typical choroideremia-like fundus changes. Ocular manifestations may be the first and the only findings for years. All of our patients carried one severe deleterious variant (stop-gain or splicing variant) and one milder variant (missense variant). Retinal involvement was significantly correlated with severe deleterious variants and variants in Pat domain.
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Affiliation(s)
- Shijing Wu
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Zixi Sun
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Tian Zhu
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Richard G Weleber
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA
| | - Paul Yang
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA
| | - Xing Wei
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Mark E Pennesi
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA.
| | - Ruifang Sui
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China.
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Organophosphorus Nerve Agents: Types, Toxicity, and Treatments. J Toxicol 2020; 2020:3007984. [PMID: 33029136 PMCID: PMC7527902 DOI: 10.1155/2020/3007984] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 08/30/2020] [Accepted: 09/10/2020] [Indexed: 01/08/2023] Open
Abstract
Organophosphorus compounds are extensively used worldwide as pesticides which cause great hazards to human health. Nerve agents, a subcategory of the organophosphorus compounds, have been produced and used during wars, and they have also been used in terrorist activities. These compounds possess physiological threats by interacting and inhibiting acetylcholinesterase enzyme which leads to the cholinergic crisis. After a general introduction, this review elucidates the mechanisms underlying cholinergic and noncholinergic effects of organophosphorus compounds. The conceivable treatment strategies for organophosphate poisoning are different types of bioscavengers which include stoichiometric, catalytic, and pseudocatalytic. The current research on the promising treatments specifically the catalytic bioscavengers including several wild-type organophosphate hydrolases such as paraoxonase and phosphotriesterase, phosphotriesterase-like lactonase, methyl parathion hydrolase, organophosphate acid anhydrolase, diisopropyl fluorophosphatase, human triphosphate nucleotidohydrolase, and senescence marker protein has been widely discussed. Organophosphorus compounds are reported to be the nonphysiological substrate for many mammalian organophosphate hydrolysing enzymes; therefore, the efficiency of these enzymes toward these compounds is inadequate. Hence, studies have been conducted to create mutants with an enhanced rate of hydrolysis and high specificity. Several mutants have been created by applying directed molecular evolution and/or targeted mutagenesis, and catalytic efficiency has been characterized. Generally, organophosphorus compounds are chiral in nature. The development of mutant enzymes for providing superior stereoselective degradation of toxic organophosphorus compounds has also been widely accounted for in this review. Existing enzymes have shown limited efficiency; hence, more effective treatment strategies have also been critically analyzed.
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Yang XR, Benson MD, MacDonald IM, Innes AM. A diagnostic approach to syndromic retinal dystrophies with intellectual disability. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2020; 184:538-570. [PMID: 32918368 DOI: 10.1002/ajmg.c.31834] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 07/30/2020] [Accepted: 08/05/2020] [Indexed: 12/20/2022]
Abstract
Inherited retinal dystrophies are a group of monogenic disorders that, as a whole, contribute significantly to the burden of ocular disease in both pediatric and adult patients. In their syndromic forms, retinal dystrophies can be observed in association with intellectual disability, frequently alongside other systemic manifestations. There are now over 80 genes implicated in syndromic retinal dystrophies with intellectual disability. Identifying and accurately characterizing these disorders allows the clinician to narrow the differential diagnosis, evaluate for relevant associated features, arrive at a timely and accurate diagnosis, and address both sight-threatening ocular manifestations and morbidity-causing systemic manifestations. The co-occurrence of retinal dystrophy and intellectual disability in an individual can be challenging to investigate, diagnose, and counsel given the considerable phenotypic and genotypic heterogeneity that exists within this broad group of disorders. We performed a review of the current literature and propose an algorithm to facilitate the evaluation, and clinical and mechanistic classification, of these individuals.
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Affiliation(s)
- Xiao-Ru Yang
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Matthew D Benson
- Department of Ophthalmology, University of Alberta, Edmonton, Alberta, Canada
| | - Ian M MacDonald
- Department of Ophthalmology, University of Alberta, Edmonton, Alberta, Canada.,Department of Medical Genetics, University of Alberta, Edmonton, Alberta, Canada
| | - A Micheil Innes
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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35
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De Silva SR, Arno G, Robson AG, Fakin A, Pontikos N, Mohamed MD, Bird AC, Moore AT, Michaelides M, Webster AR, Mahroo OA. The X-linked retinopathies: Physiological insights, pathogenic mechanisms, phenotypic features and novel therapies. Prog Retin Eye Res 2020; 82:100898. [PMID: 32860923 DOI: 10.1016/j.preteyeres.2020.100898] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 08/07/2020] [Accepted: 08/21/2020] [Indexed: 02/08/2023]
Abstract
X-linked retinopathies represent a significant proportion of monogenic retinal disease. They include progressive and stationary conditions, with and without syndromic features. Many are X-linked recessive, but several exhibit a phenotype in female carriers, which can help establish diagnosis and yield insights into disease mechanisms. The presence of affected carriers can misleadingly suggest autosomal dominant inheritance. Some disorders (such as RPGR-associated retinopathy) show diverse phenotypes from variants in the same gene and also highlight limitations of current genetic sequencing methods. X-linked disease frequently arises from loss of function, implying potential for benefit from gene replacement strategies. We review X-inactivation and X-linked inheritance, and explore burden of disease attributable to X-linked genes in our clinically and genetically characterised retinal disease cohort, finding correlation between gene transcript length and numbers of families. We list relevant genes and discuss key clinical features, disease mechanisms, carrier phenotypes and novel experimental therapies. We consider in detail the following: RPGR (associated with retinitis pigmentosa, cone and cone-rod dystrophy), RP2 (retinitis pigmentosa), CHM (choroideremia), RS1 (X-linked retinoschisis), NYX (complete congenital stationary night blindness (CSNB)), CACNA1F (incomplete CSNB), OPN1LW/OPN1MW (blue cone monochromacy, Bornholm eye disease, cone dystrophy), GPR143 (ocular albinism), COL4A5 (Alport syndrome), and NDP (Norrie disease and X-linked familial exudative vitreoretinopathy (FEVR)). We use a recently published transcriptome analysis to explore expression by cell-type and discuss insights from electrophysiology. In the final section, we present an algorithm for genes to consider in diagnosing males with non-syndromic X-linked retinopathy, summarise current experimental therapeutic approaches, and consider questions for future research.
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Affiliation(s)
- Samantha R De Silva
- UCL Institute of Ophthalmology, University College London, UK; Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Gavin Arno
- UCL Institute of Ophthalmology, University College London, UK; Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Anthony G Robson
- UCL Institute of Ophthalmology, University College London, UK; Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Ana Fakin
- UCL Institute of Ophthalmology, University College London, UK; Moorfields Eye Hospital NHS Foundation Trust, London, UK; Ljubljana University Medical Centre, Ljubljana, Slovenia
| | - Nikolas Pontikos
- UCL Institute of Ophthalmology, University College London, UK; Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Moin D Mohamed
- Department of Ophthalmology, Guy's & St Thomas' NHS Foundation Trust, London, UK
| | - Alan C Bird
- UCL Institute of Ophthalmology, University College London, UK; Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Anthony T Moore
- UCL Institute of Ophthalmology, University College London, UK; Moorfields Eye Hospital NHS Foundation Trust, London, UK; Department of Ophthalmology, UCSF School of Medicine, San Francisco, CA, USA
| | - Michel Michaelides
- UCL Institute of Ophthalmology, University College London, UK; Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Andrew R Webster
- UCL Institute of Ophthalmology, University College London, UK; Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Omar A Mahroo
- UCL Institute of Ophthalmology, University College London, UK; Moorfields Eye Hospital NHS Foundation Trust, London, UK; Department of Ophthalmology, Guy's & St Thomas' NHS Foundation Trust, London, UK; Section of Ophthalmology, King's College London, UK; Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK.
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36
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Velasco HM, Ullah E, Martin AM, Hufnagel RB, Prada CE. Novel progressive acrodysostosis-like skeletal dysplasia, cerebellar atrophy, and ichthyosis. Am J Med Genet A 2020; 182:2214-2221. [PMID: 32783359 DOI: 10.1002/ajmg.a.61782] [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: 02/24/2020] [Revised: 05/09/2020] [Accepted: 06/22/2020] [Indexed: 11/07/2022]
Abstract
Acrodysostosis refers to a rare heterogeneous group of bone dysplasias that share skeletal features, hormone resistance, and intellectual disability. Two genes have been associated with acrodysostosis with or without hormone resistance (PRKAR1A and PDE4D). Severe intellectual disability has been reported with acrodysostosis but brain malformations and ichthyosis have not been reported in these syndromes. Here we describe a female patient with acrodysostosis, intellectual disability, cerebellar hypoplasia, and lamellar ichthyosis. The patient has an evolving distinctive facial phenotype and childhood onset ataxia. X-rays showed generalized osteopenia, shortening of middle and distal phalanges, and abnormal distal epiphysis of the ulna and radius. Brain magnetic resonance imaging showed cerebellar atrophy without other brainstem abnormalities. Genetic workup included nondiagnostic chromosomal microarray and skeletal dysplasia molecular panels. These clinical findings are different from any recognized form of acrodysostosis syndrome. Whole exome sequencing did not identify rare or predicted pathogenic variants in genes associated with known acrodysostosis, lamellar ichthyosis, and other overlapping disorders. A broader search for rare alleles absent in healthy population databases and controls identified two heterozygous truncating alleles in FBNL7 and PPM1M genes, and one missense allele in the NPEPPS gene. Identification of additional patients is required to delineate the mechanism of this unique disorder.
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Affiliation(s)
- Harvy M Velasco
- Master of Science in Human Genetics Program, Department of Morphology, Universidad Nacional de Colombia, Cundinamarca, Colombia
| | - Ehsan Ullah
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Angela M Martin
- Master of Science in Human Genetics Program, Department of Morphology, Universidad Nacional de Colombia, Cundinamarca, Colombia
| | - Robert B Hufnagel
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Carlos E Prada
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
- Fundación Cardiovascular de Colombia, Bucaramanga, Colombia
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
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37
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Sen K, Finau M, Ghosh P. Bi-allelic variants in PNPLA6 possibly associated with Parkinsonian features in addition to spastic paraplegia phenotype. J Neurol 2020; 267:2749-2753. [PMID: 32623594 DOI: 10.1007/s00415-020-10028-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 06/22/2020] [Accepted: 06/25/2020] [Indexed: 01/28/2023]
Abstract
Variants in the PNPLA6 gene are known to cause 4 distinct phenotypes. One known phenotype is Hereditary Spastic Paraplegia type 39 (HSP 39), a rare neurodegenerative condition characterized by variable onset of lower limb spasticity, weakness and ataxia. Little is known about complications of HSP 39 in adulthood. Here, we report a family of three siblings who presented with bilateral lower limb spasticity in childhood, consistent with HSP, with confirmed bi-allellic PNPLA6 mutations. Two siblings developed parkinsonian features in middle age, a novel finding in this sibship. The proband had a positive dopamine transporter scan, indicating degeneration in dopaminergic neurons, and dopa-responsive extrapyramidal symptoms. Testing for known genetic causes of Parkinsonism was negative. The PNPLA6 gene encodes neuropathy target esterase, an enzyme involved in lipid metabolism that is critical to the stability of cell membranes. We hypothesize that the development of Parkinsonism in these patients may be related to the PNPLA6 mutations, as lipid dysregulation has been implicated in the pathogenesis of Parkinson disease.
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Affiliation(s)
- Kuntal Sen
- Division of Neurogenetics and Developmental Pediatrics, Children's National Hospital, 111 Michigan Ave, NW, Washington, DC, 20010, USA.
| | - Melesilika Finau
- Parkinson Disease and Movement Disorders Program, Department of Neurology, Medical Faculty Associates, George Washington University, Washington, DC, USA
| | - Pritha Ghosh
- Parkinson Disease and Movement Disorders Program, Department of Neurology, Medical Faculty Associates, George Washington University, Washington, DC, USA
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38
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Makuloluwa AK, Dodeja R, Georgiou M, Gonzalez-Martin J, Hagan R, Madhusudhan S, Michaelides M. Oliver McFarlane syndrome and choroidal neovascularisation: a case report. Ophthalmic Genet 2020; 41:451-456. [PMID: 32586184 DOI: 10.1080/13816810.2020.1783689] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
BACKGROUND Oliver McFarlane syndrome (OMS) is a rare autosomal recessive disorder characterised by pigmentary chorioretinal atrophy with no previous reports of choroidal neovascularisation (CNV). MATERIAL AND METHODS We describe the history, findings of clinical examination, retinal imaging and electrodiagnostic studies, and the treatment of a patient with CNV secondary to OMS. CASE DESCRIPTION CNV secondary to OMS was diagnosed in a ten-year-old white female who presented with reduced visual acuity and a macular haemorrhage in her right eye. CNV was confirmed on optical coherence tomography. She was initially treated with a single injection of intravitreal bevacizumab and 2 years later with an injection of intravitreal ranibizumab for a recurrence. Although macular scarring secondary to the CNV was observed, her vision has stabilised and she continues to be closely monitored. CONCLUSION We report the first case of CNV secondary to OMS and its successful treatment with intravitreal anti-vascular endothelial growth factor injections.
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Affiliation(s)
| | - Rutika Dodeja
- St. Paul's Eye Unit, Royal Liverpool University Hospital , Liverpool, UK.,Department of Ophthalmology, Alder Hey Children's Hospital , Liverpool, UK
| | - Michalis Georgiou
- Moorfields Eye Hospital , London, UK.,UCL Institute of Ophthalmology, University College London , London, UK
| | | | - Richard Hagan
- Department of Electrophysiology, Royal Liverpool University Hospital , Liverpool, UK
| | - Savita Madhusudhan
- St. Paul's Eye Unit, Royal Liverpool University Hospital , Liverpool, UK
| | - Michel Michaelides
- Moorfields Eye Hospital , London, UK.,UCL Institute of Ophthalmology, University College London , London, UK
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39
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Richardson RJ, Fink JK, Glynn P, Hufnagel RB, Makhaeva GF, Wijeyesakere SJ. Neuropathy target esterase (NTE/PNPLA6) and organophosphorus compound-induced delayed neurotoxicity (OPIDN). ADVANCES IN NEUROTOXICOLOGY 2020; 4:1-78. [PMID: 32518884 PMCID: PMC7271139 DOI: 10.1016/bs.ant.2020.01.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Systemic inhibition of neuropathy target esterase (NTE) with certain organophosphorus (OP) compounds produces OP compound-induced delayed neurotoxicity (OPIDN), a distal degeneration of axons in the central nervous system (CNS) and peripheral nervous system (PNS), thereby providing a powerful model for studying a spectrum of neurodegenerative diseases. Axonopathies are important medical entities in their own right, but in addition, illnesses once considered primary neuronopathies are now thought to begin with axonal degeneration. These disorders include Alzheimer's disease, Parkinson's disease, and motor neuron diseases such as amyotrophic lateral sclerosis (ALS). Moreover, conditional knockout of NTE in the mouse CNS produces vacuolation and other degenerative changes in large neurons in the hippocampus, thalamus, and cerebellum, along with degeneration and swelling of axons in ascending and descending spinal cord tracts. In humans, NTE mutations cause a variety of neurodegenerative conditions resulting in a range of deficits including spastic paraplegia and blindness. Mutations in the Drosophila NTE orthologue SwissCheese (SWS) produce neurodegeneration characterized by vacuolization that can be partially rescued by expression of wild-type human NTE, suggesting a potential therapeutic approach for certain human neurological disorders. This chapter defines NTE and OPIDN, presents an overview of OP compounds, provides a rationale for NTE research, and traces the history of discovery of NTE and its relationship to OPIDN. It then briefly describes subsequent studies of NTE, including practical applications of the assay; aspects of its domain structure, subcellular localization, and tissue expression; abnormalities associated with NTE mutations, knockdown, and conventional or conditional knockout; and hypothetical models to help guide future research on elucidating the role of NTE in OPIDN.
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Affiliation(s)
- Rudy J. Richardson
- Molecular Simulations Laboratory, Department of Environmental Health Sciences, University of Michigan, Ann Arbor, MI, United States,Department of Neurology, University of Michigan Medical School, Ann Arbor, MI, United States,Center for Computational Medicine and Bioinformatics, University of Michigan Medical School, Ann Arbor, MI, United States,Michigan Institute for Computational Discovery and Engineering, University of Michigan, Ann Arbor, MI, United States,Corresponding author:
| | - John K. Fink
- Department of Neurology, University of Michigan Medical School, Ann Arbor, MI, United States,Ann Arbor Veterans Affairs Medical Center, Ann Arbor, MI, United States
| | - Paul Glynn
- Department of Molecular and Cell Biology, University of Leicester, Leicester, United Kingdom
| | - Robert B. Hufnagel
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD, United States
| | - Galina F. Makhaeva
- Institute of Physiologically Active Compounds Russian Academy of Sciences, Chernogolovka, Russia
| | - Sanjeeva J. Wijeyesakere
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, United States
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40
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Naef V, Mero S, Fichi G, D'Amore A, Ogi A, Gemignani F, Santorelli FM, Marchese M. Swimming in Deep Water: Zebrafish Modeling of Complicated Forms of Hereditary Spastic Paraplegia and Spastic Ataxia. Front Neurosci 2019; 13:1311. [PMID: 31920481 PMCID: PMC6914767 DOI: 10.3389/fnins.2019.01311] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 11/22/2019] [Indexed: 12/13/2022] Open
Abstract
Hereditary spastic paraplegia (HSP) and hereditary ataxia (HA) are two groups of disorders characterized, respectively, by progressive dysfunction or degeneration of the pyramidal tracts (HSP) and of the Purkinje cells and spinocerebellar tracts (HA). Although HSP and HA are generally shown to have distinct clinical-genetic profiles, in several cases the clinical presentation, the causative genes, and the cellular pathways and mechanisms involved overlap between the two forms. Genetic analyses in humans in combination with in vitro and in vivo studies using model systems have greatly expanded our knowledge of spinocerebellar degenerative disorders. In this review, we focus on the zebrafish (Danio rerio), a vertebrate model widely used in biomedical research since its overall nervous system organization is similar to that of humans. A critical analysis of the literature suggests that zebrafish could serve as a powerful experimental tool for molecular and genetic dissection of both HA and HSP. The zebrafish, found to be very useful for demonstrating the causal relationship between defect and mutation, also offers a useful platform to exploit for the development of therapies.
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Affiliation(s)
- Valentina Naef
- Neurobiology and Molecular Medicine, IRCCS Stella Maris, Pisa, Italy
| | - Serena Mero
- Neurobiology and Molecular Medicine, IRCCS Stella Maris, Pisa, Italy.,Department of Biology, University of Pisa, Pisa, Italy
| | - Gianluca Fichi
- Neurobiology and Molecular Medicine, IRCCS Stella Maris, Pisa, Italy.,Struttura Complessa Toscana Sud (Sede Grosseto), Istituto Zooprofilattico Sperimentale del Lazio e Toscana M. Aleandri, Grosseto, Italy
| | - Angelica D'Amore
- Neurobiology and Molecular Medicine, IRCCS Stella Maris, Pisa, Italy.,Department of Biology, University of Pisa, Pisa, Italy.,Department of Neurology, The F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States
| | - Asahi Ogi
- Neurobiology and Molecular Medicine, IRCCS Stella Maris, Pisa, Italy.,Department of Veterinary Sciences, University of Pisa, Pisa, Italy
| | | | | | - Maria Marchese
- Neurobiology and Molecular Medicine, IRCCS Stella Maris, Pisa, Italy
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41
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Characterization of the Interaction of Neuropathy Target Esterase with the Endoplasmic Reticulum and Lipid Droplets. Biomolecules 2019; 9:biom9120848. [PMID: 31835418 PMCID: PMC6995513 DOI: 10.3390/biom9120848] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 12/05/2019] [Accepted: 12/05/2019] [Indexed: 12/02/2022] Open
Abstract
Neuropathy target esterase (NTE) is an endoplasmic reticulum (ER)-localized phospholipase that deacylates phosphatidylcholine (PC) and lysophosphatidylcholine (LPC). Loss-of-function mutations in the human NTE gene have been associated with a spectrum of neurodegenerative disorders such as hereditary spastic paraplegia, ataxia and chorioretinal dystrophy. Despite this, little is known about structure–function relationships between NTE protein domains, enzymatic activity and the interaction with cellular organelles. In the current study we show that the C-terminal region of NTE forms a catalytically active domain that exhibits high affinity for lipid droplets (LDs), cellular storage organelles for triacylglycerol (TAG), which have been recently implicated in the progression of neurodegenerative diseases. Ectopic expression of the C domain in cultured cells decreases cellular PC, elevates TAG and induces LD clustering. LD interactions of NTE are inhibited by default by a non-enzymatic regulatory (R) region with three putative nucleotide monophosphate binding sites. Together with a N-terminal TMD the R region promotes proper distribution of the catalytic C-terminal region to the ER network. Taken together, our data indicate that NTE may exhibit dynamic interactions with the ER and LDs depending on the interplay of its functional regions. Mutations that disrupt this interplay may contribute to NTE-associated disorders by affecting NTE positioning.
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Sunderhaus ER, Law AD, Kretzschmar D. Disease-Associated PNPLA6 Mutations Maintain Partial Functions When Analyzed in Drosophila. Front Neurosci 2019; 13:1207. [PMID: 31780887 PMCID: PMC6852622 DOI: 10.3389/fnins.2019.01207] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 10/25/2019] [Indexed: 12/22/2022] Open
Abstract
Mutations in patatin-like phospholipase domain-containing protein 6 (PNPLA6) have been linked with a number of inherited diseases with clinical symptoms that include spastic paraplegia, ataxia, and chorioretinal dystrophy. PNPLA6 is an evolutionary conserved protein whose ortholog in Drosophila is Swiss-Cheese (SWS). Both proteins are phospholipases hydrolyzing lysophosphatidylcholine (LPC) and phosphatidylcholine (PC). Consequently, loss of SWS/PNPLA6 in flies and mice increases both lipids and leads to locomotion deficits and neurodegeneration. PNPLA6 knock-out mice are embryonic lethal, and a mutation creating an early stop codon in human PNPLA6 has only been identified in compound heterozygote patients. In contrast, disease-causing point mutations are found in homozygous patients, with some localized in the phospholipase domain while others are in a region that contains several cNMP binding sites. To investigate how different mutations affect the function of PNPLA6 in an in vivo model, we expressed them in the Drosophila sws1 null mutant. Expressing wild-type PNPLA6 suppressed the locomotion and degenerative phenotypes in sws 1 and restored lipid levels, confirming that the human protein can replace fly SWS. In contrast, none of the mutant proteins restored lipid levels, although they suppressed the behavioral and degenerative phenotypes, at least in early stages. These results show that these mutant forms of PNPLA6 retain some biological function, indicating that disruption of lipid homeostasis is only part of the pathogenic mechanism. Furthermore, our finding that mutations in the cNMP binding sites prevented the restoration of normal lipid levels supports previous evidence that cNMP regulates the phospholipase activity of PNPLA6.
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Affiliation(s)
| | | | - Doris Kretzschmar
- Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, OR, United States
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Abstract
PURPOSE OF REVIEW Hereditary myelopathies are very diverse genetic disorders, and many of them represent a widespread neurodegenerative process rather than isolated spinal cord dysfunction. This article reviews various types of inherited myelopathies, with emphasis on hereditary spastic paraplegias and spastic ataxias. RECENT FINDINGS The ever-growing number of myelopathy-causing genes and broadening of phenotype-genotype correlations makes the molecular diagnosis of inherited myelopathies a daunting task. This article emphasizes the main phenotypic clusters among inherited myelopathies that can facilitate the diagnostic process. This article focuses on newly identified genetic causes and the most important identifying clinical features that can aid the diagnosis, including the presence of a characteristic age of onset and additional neurologic signs such as leukodystrophy, thin corpus callosum, or amyotrophy. SUMMARY The exclusion of potentially treatable causes of myelopathy remains the most important diagnostic step. Syndromic diagnosis can be supported by molecular diagnosis, but the genetic diagnosis at present does not change the management. Moreover, a negative genetic test does not exclude the diagnosis of a hereditary myelopathy because comprehensive molecular testing is not yet available, and many disease-causing genes remain unknown.
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Teive HAG, Camargo CHF, Sato MT, Shiokawa N, Boguszewski CL, Raskin S, Buck C, Seminara SB, Munhoz RP. Different Cerebellar Ataxia Phenotypes Associated with Mutations of the PNPLA6 Gene in Brazilian Patients with Recessive Ataxias. THE CEREBELLUM 2019; 17:380-385. [PMID: 29248984 DOI: 10.1007/s12311-017-0909-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Autosomal recessive cerebellar ataxias (ARCAs) represent a heterogeneous group of inherited disorders. The association of early-onset cerebellar ataxia with hypogonadotropic hypogonadism is related to two syndromes, known as Gordon Holmes syndrome (GHS-ataxia and pyramidal signs with hypogonadotropic hypogonadism) and Boucher-Neuhäuser syndrome (BNS-ataxia with chorioretinal dystrophy). Mutations in the PNPLA6 gene have been identified as the cause of hereditary spastic paraplegia and complex forms of ataxia associated with retinal and endocrine manifestations. We reported two Brazilian patients with sporadic, progressive cerebellar ataxia, associated with hypogonadotropic hypogonadism, in whom the GHS and BNS were confirmed by the demonstration of compound heterozygote mutations in the PNPLA6 gene. Genetic analysis of the patient 1 revealed compound heterozygous mutations, one allele in exon 34 and the other allele in exon 29. Genetic exam of the patient 2 also demonstrated compound heterozygous mutations. Three were novel mutations. The missense mutation c.3373G> A, found in the BNS patient, was previously related to Oliver-McFarlane syndrome. These different mutations in this gene suggest a complex phenotype associated disease spectrum.
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Affiliation(s)
- Hélio Afonso Ghizoni Teive
- Movement Disorders Unit, Neurology Service, Internal Medicine Department, Hospital de Clínicas, Federal University of Paraná, Rua General Carneiro 1103/102, Centro, Curitiba, PR, 80060-150, Brazil.
| | - Carlos Henrique F Camargo
- Neurology Service, Hospital Universitário, State University of Ponta Grossa, Ponta Grossa, PR, Brazil
| | - Mario Teruo Sato
- Neuro-Ophthalmology Unit, Ophthalmology Service, Hospital de Clínicas, Federal University of Paraná, Curitiba, PR, Brazil
| | | | - Cesar L Boguszewski
- Endocrine Division (SEMPR), Internal Medicine Department, Hospital de Clínicas, Federal University of Paraná, Curitiba, PR, Brazil
| | - Salmo Raskin
- Group for Advanced Molecular Investigation, Graduate Program in Health Sciences, School of Medicine, Pontifícia Universidade Católica do Paraná, Curitiba, PR, Brazil
- Genetika-Centro de Aconselhamento e Laboratório de Genética, Curitiba, PR, Brazil
| | - Cassandra Buck
- Harvard Reproductive Sciences Center and Reproductive Endocrine Unit, Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Stephanie B Seminara
- Harvard Reproductive Sciences Center and Reproductive Endocrine Unit, Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Renato Puppi Munhoz
- Morton and Gloria Shulman Movement Disorders Centre and the Edmond J. Safra Program in Parkinson's Disease, Toronto Western Hospital, University Health Network, Toronto, ON, Canada
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O’Neil E, Serrano L, Scoles D, Cunningham KE, Han G, Chiang J, Bennett J, Aleman TS. Detailed retinal phenotype of Boucher-Neuhäuser syndrome associated with mutations in PNPLA6 mimicking choroideremia. Ophthalmic Genet 2019; 40:267-275. [DOI: 10.1080/13816810.2019.1605392] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Erin O’Neil
- Scheie Eye Institute and the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Leona Serrano
- Scheie Eye Institute and the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- The Center for Advanced Retinal and Ocular Therapeutics, Department of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Drew Scoles
- Scheie Eye Institute and the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | - Grace Han
- Scheie Eye Institute and the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - John Chiang
- Molecular Vision Laboratory, Hillsboro, OR, USA
| | - Jean Bennett
- Scheie Eye Institute and the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- The Center for Advanced Retinal and Ocular Therapeutics, Department of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Tomas S. Aleman
- Scheie Eye Institute and the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- The Center for Advanced Retinal and Ocular Therapeutics, Department of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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Alexander V, George T, Devarajan G, Zachariah A. Acute myocardial infarction and haemodynamic stroke in a young patient with Bardet-Biedl syndrome. BMJ Case Rep 2019; 12:12/4/e229788. [PMID: 31040148 DOI: 10.1136/bcr-2019-229788] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
A 28-year-old man diagnosed with diabetes mellitus and systemic hypertension presented with a medical history of sudden onset retrosternal discomfort followed by loss of consciousness and generalised tonic clonic seizures. Examination revealed obesity, polysyndactyly and retinal pigment dystrophy. He was diagnosed to have acute myocardial infarction and left posterior watershed infarct. He was also diagnosed to have Bardet-Biedl syndrome based on clinical features. He was managed symptomatically and is currently doing well on regular follow-up in the outpatient clinic.
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Affiliation(s)
- Vijay Alexander
- Department of Medicine, Christian Medical College and Hospital, Vellore, Tamil Nadu, India
| | - Tina George
- Department of Medicine, Christian Medical College and Hospital, Vellore, Tamil Nadu, India
| | - Gifty Devarajan
- Department of Medicine, Christian Medical College and Hospital, Vellore, Tamil Nadu, India
| | - Anand Zachariah
- Department of Medicine, Christian Medical College and Hospital, Vellore, Tamil Nadu, India
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Khan OA, Majeed R, Saad M, Khan A, Ghassan A. Rarity of Laurence Moon Bardet Biedl Syndrome and its Poor Management in the Pakistani Population. Cureus 2019; 11:e4114. [PMID: 31058008 PMCID: PMC6476609 DOI: 10.7759/cureus.4114] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Laurence Moon Bardet Biedl syndrome is characterized as a rare genetic disorder, with a wide range of presenting symptoms such as mental retardation, decreased visual acuity, obesity, hypogonadism, and polydactyly. The diagnosis of this syndrome is easily overlooked due to its rarity, with a prevalence rate of one in 125,000-160,000 reported within Europe. Delayed diagnosis and inappropriate management may lead to an irreversible loss of functions. The most significant of these losses include loss of vision, cardiac problems, and renal abnormalities. These dysfunctions critically impact the mental faculties and personal life of a patient. Our case presented with striking features of this syndrome, but due to a lack of awareness, her family was not adequately counseled. Both the family and the patient were not equipped with the necessary knowledge regarding the nature of her disease and its prognosis. The patient was mismanaged and kept ignorant of the importance of a proper follow-up. This necessitates a multidisciplinary team approach towards such cases so that their disease can be adequately managed. The early diagnosis and symptomatic management of complications as they arise remain the most important and vital step in the management of this illness. We hope that our case sheds further light on the existing knowledge of this syndrome.
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Affiliation(s)
- Omair A Khan
- Internal Medicine, Fauji Foundation Hospital, Islamabad, PAK
| | - Ramsha Majeed
- Internal Medicine, Fauji Foundation Hospital, Islamabad, PAK
| | - Muhammad Saad
- Internal Medicine, Fauji Foundation Hospital, Islamabad, PAK
| | - Asad Khan
- Internal Medicine, Fauji Foundation Hospital, Islamabad, PAK
| | - Ayesha Ghassan
- Medical Education and Simulation, Fauji Foundation Hospital, Islamabad, PAK
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Pan H, Xiang H, Wang J, Wei Z, Zhou Y, Liu B, Li T, Ma X, Cao Y, Wang B. CAPS Mutations Are Potentially Associated with Unexplained Recurrent Pregnancy Loss. THE AMERICAN JOURNAL OF PATHOLOGY 2019; 189:124-131. [DOI: 10.1016/j.ajpath.2018.09.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 08/31/2018] [Accepted: 09/10/2018] [Indexed: 12/20/2022]
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Donato L, Scimone C, Nicocia G, D'Angelo R, Sidoti A. Role of oxidative stress in Retinitis pigmentosa: new involved pathways by an RNA-Seq analysis. Cell Cycle 2018; 18:84-104. [PMID: 30569795 DOI: 10.1080/15384101.2018.1558873] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Retinitis pigmentosa (RP) is a very heterogeneous inherited ocular disorder group characterized by progressive retinal disruption. Retinal pigment epithelium (RPE) degeneration, due to oxidative stress which arrests the metabolic support to photoreceptors, represents one of the principal causes of RP. Here, the role of oxidative stress in RP onset and progression was analyzed by a comparative whole transcriptome analysis of human RPE cells, treated with 100 µg/ml of oxLDL and untreated, at different time points. Experiment was thrice repeated and performed on Ion ProtonTM sequencing system. Data analysis, including low quality reads trimming and gene expression quantification, was realized by CLC Genomics Workbench software. The whole analysis highlighted 14 clustered "macro-pathways" and many sub-pathways, classified by selection of 5271 genes showing the highest alteration of expression. Among them, 23 genes were already known to be RP causative ones (15 over-expressed and 8 down-expressed), and their enrichment and intersection analyses highlighted new 77 candidate related genes (49 over-expressed and 28 down-expressed). A final filtering analysis then highlighted 29 proposed candidate genes. This data suggests that many new genes, not yet associated with RP, could influence its etiopathogenesis.
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Affiliation(s)
- Luigi Donato
- a Department of Biomedical and Dental Sciences and Morphofunctional Imaging, Division of Medical Biotechnologies and Preventive Medicine , University of Messina , Messina , Italy.,b Department of Cutting-Edge Medicine and Therapies, Biomolecular Strategies and Neuroscience, Section of Applied Neuroscience, Molecular Genetics and Predictive Medicine , I.E.ME.S.T. ., Palermo , Italy
| | - Concetta Scimone
- a Department of Biomedical and Dental Sciences and Morphofunctional Imaging, Division of Medical Biotechnologies and Preventive Medicine , University of Messina , Messina , Italy.,b Department of Cutting-Edge Medicine and Therapies, Biomolecular Strategies and Neuroscience, Section of Applied Neuroscience, Molecular Genetics and Predictive Medicine , I.E.ME.S.T. ., Palermo , Italy
| | - Giacomo Nicocia
- c Department of Clinical and Experimental Medicine , University of Messina , Messina , Italy
| | - Rosalia D'Angelo
- a Department of Biomedical and Dental Sciences and Morphofunctional Imaging, Division of Medical Biotechnologies and Preventive Medicine , University of Messina , Messina , Italy.,b Department of Cutting-Edge Medicine and Therapies, Biomolecular Strategies and Neuroscience, Section of Applied Neuroscience, Molecular Genetics and Predictive Medicine , I.E.ME.S.T. ., Palermo , Italy
| | - Antonina Sidoti
- a Department of Biomedical and Dental Sciences and Morphofunctional Imaging, Division of Medical Biotechnologies and Preventive Medicine , University of Messina , Messina , Italy.,b Department of Cutting-Edge Medicine and Therapies, Biomolecular Strategies and Neuroscience, Section of Applied Neuroscience, Molecular Genetics and Predictive Medicine , I.E.ME.S.T. ., Palermo , Italy
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Gordon Holmes syndrome due to compound heterozygosity of two new PNPLA6 variants - A diagnostic challenge. eNeurologicalSci 2018; 14:9-12. [PMID: 30555943 PMCID: PMC6275202 DOI: 10.1016/j.ensci.2018.11.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 11/17/2018] [Indexed: 12/15/2022] Open
Abstract
Background Gordon Holmes syndrome (GHS), characterized by cerebellar ataxia and hypogonadotropic hypogonadism (HH), has been related to recessive mutations in PNPLA6 gene. Aims of the study Describe one Portuguese family with GHS due to compound heterozygosity of two new PNPLA6 variants. Methods Report on the clinical presentation, diagnostic and genetic workup to reach GHS diagnosis. Results The index case presented with slight cognitive impairment and primary amenorrhea, developed at the age of 25 a cerebellar syndrome. Her neurological exam revealed ataxia and mild extrapyramidal syndrome. She was born from non-consanguineous parents and had 8 siblings. Two of her sisters also had history of primary amenorrhea, tremor and ataxia. All 3 were diagnosed with HH and previous FMR1 gene screening on her sisters revealed a 51 CGGs allele. However, 2 normal-sized FMR1 alleles were identified on the proband thus excluding the FXTAS diagnosis in the family. Further PNPLA6 variant screening revealed 2 novel variants in compound heterozygosity [c.2404G > C]; [c.4081C > T], which co-segregated with the disease. Conclusions This case shows how incomplete studies can be misleading, increases genetic knowledge of GHS and expands its clinical spectrum. The coexistence of a FMR1 intermediate allele in this family constituted an additional challenge in the etiological investigation.
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