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Dehnavi AZ, Bemanalizadeh M, Kahani SM, Ashrafi MR, Rohani M, Toosi MB, Heidari M, Hosseinpour S, Amini B, Zokaei S, Rezaei Z, Aryan H, Amanat M, Vahidnezhad H, Mohammadi P, Garshasbi M, Tavasoli AR. Phenotype and genotype heterogeneity of PLA2G6-associated neurodegeneration in a cohort of pediatric and adult patients. Orphanet J Rare Dis 2023; 18:177. [PMID: 37403138 DOI: 10.1186/s13023-023-02780-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 06/18/2023] [Indexed: 07/06/2023] Open
Abstract
BACKGROUND Phospholipase-associated neurodegeneration (PLAN) caused by mutations in the PLA2G6 gene is a rare neurodegenerative disorder that presents with four sub-groups. Infantile neuroaxonal dystrophy (INAD) and PLA2G6-related dystonia-parkinsonism are the main two subtypes. In this cohort, we reviewed clinical, imaging, and genetic features of 25 adult and pediatric patients harboring variants in the PLA2G6. METHODS An extensive review of the patients' data was carried out. Infantile Neuroaxonal Dystrophy Rating Scale (INAD-RS) was used for evaluating the severity and progression of INAD patients. Whole-exome sequencing was used to determine the disease's underlying etiology followed by co-segregation analysis using Sanger sequencing. In silico prediction analysis based on the ACMG recommendation was used to assess the pathogenicity of genetic variants. We aimed to survey a genotype-genotype correlation in PLA2G6 considering all reported disease-causing variants in addition to our patients using the HGMD database and the chi-square statistical approach. RESULTS Eighteen cases of INAD and 7 cases of late-onset PLAN were enrolled. Among 18 patients with INAD, gross motor regression was the most common presenting symptom. Considering the INAD-RS total score, the mean rate of progression was 0.58 points per month of symptoms (Standard error 0.22, lower 95% - 1.10, and upper 95% - 0.15). Sixty percent of the maximum potential loss in the INAD-RS had occurred within 60 months of symptom onset in INAD patients. Among seven adult cases of PLAN, hypokinesia, tremor, ataxic gate, and cognitive impairment were the most frequent clinical features. Various brain imaging abnormalities were also observed in 26 imaging series of these patients with cerebellar atrophy being the most common finding in more than 50%. Twenty unique variants in 25 patients with PLAN were detected including nine novel variants. Altogether, 107 distinct disease-causing variants from 87 patient were analyzed to establish a genotype-phenotype correlation. The P value of the chi-square test did not indicate a significant relationship between age of disease onset and the distribution of reported variants on PLA2G6. CONCLUSION PLAN presents with a wide spectrum of clinical symptoms from infancy to adulthood. PLAN should be considered in adult patients with parkinsonism or cognition decline. Based on the current knowledge, it is not possible to foresee the age of disease onset based on the identified genotype.
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Affiliation(s)
- Ali Zare Dehnavi
- Department of Pediatrics, Division of Pediatric Neurology, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran
| | - Maryam Bemanalizadeh
- Department of Pediatrics, Division of Pediatric Neurology, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran
- Child Growth and Development Research Center, Research Institute for Primordial Prevention of Non-Communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Seyyed Mohammad Kahani
- Faculty of Medical Sciences, Department of Medical Genetics, Tarbiat Modares University, Tehran, Iran
| | - Mahmoud Reza Ashrafi
- Department of Pediatrics, Division of Pediatric Neurology, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Rohani
- Skull Base Research Center, The Five Senses Health Institute, Rasoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran
- Department of Neurology, Rasoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran
| | - Mehran Beiraghi Toosi
- Department of Pediatrics, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
- Neuroscience Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Morteza Heidari
- Department of Pediatrics, Division of Pediatric Neurology, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran
| | - Sareh Hosseinpour
- Department of Pediatrics, Division of Pediatric Neurology, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran
| | - Behnam Amini
- Department of Pediatrics, Division of Pediatric Neurology, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran
| | - Shaghayegh Zokaei
- Dr. Farhud's Genetic Clinic, Tehran, Iran
- School of Advanced Medical Science, Islamic Azad University, Tehran, Iran
| | - Zahra Rezaei
- Department of Pediatrics, Division of Pediatric Neurology, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran
| | - Hajar Aryan
- Dr. Farhud's Genetic Clinic, Tehran, Iran
- National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
| | - Man Amanat
- Department of Neurology, Johns Hopkins Medicine, Baltimore, MD, USA
| | - Hassan Vahidnezhad
- Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, PA, USA
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Pouria Mohammadi
- Faculty of Medical Sciences, Department of Medical Genetics, Tarbiat Modares University, Tehran, Iran
- Pediatric Neurology Division, Children's Medical Center, Pediatrics Center of Excellence, Ataxia Clinic, Tehran University of Medical Sciences, Tehran, Iran
| | - Masoud Garshasbi
- Faculty of Medical Sciences, Department of Medical Genetics, Tarbiat Modares University, Tehran, Iran.
| | - Ali Reza Tavasoli
- Department of Pediatrics, Division of Pediatric Neurology, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran.
- Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, PA, USA.
- Pediatric Neurology Division, Children's Medical Center, Pediatrics Center of Excellence, Ataxia Clinic, Tehran University of Medical Sciences, Tehran, Iran.
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Xue J, Ding DX, Xu GY, Wang PZ, Ge YL, Zhang JR, Cheng XY, Wang YM, Jin H, Luo SY, Zheng YH, Chen J, Wang F, Li D, Mao CJ, Li K, Liu CF. A systematic analysis of genotype-phenotype associations with PLA2G6. Parkinsonism Relat Disord 2023; 112:105477. [PMID: 37285793 DOI: 10.1016/j.parkreldis.2023.105477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 05/23/2023] [Accepted: 05/30/2023] [Indexed: 06/09/2023]
Abstract
BACKGROUND PLA2G6-associated neurodegeneration (PLAN) can be categorized into infantile neuroaxonal dystrophy (INAD), atypical neuroaxonal dystrophy (aNAD), neurodegeneration with brain iron accumulation (NBIA), and early-onset parkinsonism (EOP). OBJECTIVES To determine the genotype-phenotype association in PLAN. METHODS "PLA2G6" or "PARK14" or "phospholipase A2 group VI" or "iPLA2β" were searched across MEDLINE from June 23, 1997, to March 1, 2023. A total of 391 patients were identified, and 340 patients of them were finally included in the assessment. RESULTS The loss of function (LOF) mutation ratios were significantly different (p < 0.001), highest in INAD, followed by NBIA, aNAD, and EOP. Four ensemble scores (i.e., BayesDel, VARITY, ClinPred, and MetaRNN) were assessed to predict the deleteriousness of missense mutations and demonstrated significant differences (p < 0.001). Binary logistic regression analyses demonstrated that LOF mutations were independently associated with brain iron accumulation (p = 0.006) and ataxia (p = 0.025). CONCLUSIONS LOF or more deleterious missense mutations are more likely to promote the development of serious phenotype of PLAN, and LOF mutations are independently associated with brain iron accumulation and ataxia.
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Affiliation(s)
- Jian Xue
- Department of Neurology and Suzhou Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Dong-Xue Ding
- Department of Neurology, The First Affiliated Hospital of Soochow University, Suzhou, China
| | | | - Pu-Zhi Wang
- Department of Neurology and Suzhou Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Yi-Lun Ge
- Department of Neurology and Suzhou Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Jin-Ru Zhang
- Department of Neurology and Suzhou Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Xiao-Yu Cheng
- Department of Neurology and Suzhou Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Yi-Ming Wang
- Department of Neurology and Suzhou Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Hong Jin
- Department of Neurology and Suzhou Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | | | | | - Jing Chen
- Department of Neurology and Suzhou Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Fen Wang
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University, Suzhou, China
| | - Dan Li
- Department of Neurology, Suqian First People's Hospital, Suqian, China
| | - Cheng-Jie Mao
- Department of Neurology and Suzhou Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou, China; Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University, Suzhou, China
| | - Kai Li
- Department of Neurology and Suzhou Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou, China.
| | - Chun-Feng Liu
- Department of Neurology and Suzhou Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou, China; Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University, Suzhou, China; Department of Neurology, Suqian First People's Hospital, Suqian, China.
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Wan Y, Jiang Y, Xie Z, Ling C, Du K, Li R, Yuan Y, Wang Z, Sun W, Jin H. Novel PLA2G6 Pathogenic Variants in Chinese Patients With PLA2G6-Associated Neurodegeneration. Front Neurol 2022; 13:922528. [PMID: 35911906 PMCID: PMC9327523 DOI: 10.3389/fneur.2022.922528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 06/20/2022] [Indexed: 11/15/2022] Open
Abstract
Background PLA2G6-associated neurodegeneration (PLAN) is a heterogeneous group of neurodegenerative diseases caused by biallelic PLA2G6 mutations, covering diseases such as infantile neuroaxonal dystrophy (INAD), atypical neuroaxonal dystrophy (ANAD), dystonia parkinsonism (DP), and autosomal recessive early-onset parkinsonism (AREP). The study aims to report the clinical and genetic features of a series of PLAN patients. Methods The clinical and radiological findings of five Chinese patients from three families were collected. Whole-exome next generation sequencing (NGS) was applied to identify the genetic causes. Co-segregation analysis of the detected candidate variants were performed in their families. The pathogenicity of identified novel variants was predicted by in silico analysis. Results NGS revealed compound heterozygous variants of PLA2G6 gene in all five patients. There were six PLA2G6 variants identified, including two known variants (c.116G>A, c.238G>A) and four novel variants (c.2120dupA, c.2071C>G, c.967G>A, c1534T>A). ACMG predicts c.2120dupA to be pathogenic, c.2071C>G and c.1534T>A to be likely pathogenic, and c1534T>A to be of uncertain significance. Clinically, four patients fell into the diagnosis of ANAD, and 1 into the diagnosis of AREP. Brain imaging revealed cerebellar atrophy, iron deposition in bilateral globus pallidus, and substantia nigra in three cases. Conclusions Four novel pathogenic variants were discovered and the pathogenic variant spectrum of the PLA2G6 gene was expanded.
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Affiliation(s)
- Yalan Wan
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Yanyan Jiang
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Zhiying Xie
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Chen Ling
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Kang Du
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Ran Li
- Department of Neurology, Huoguosi TCM Hospital Affiliated to Beijing University of Chinese Medicine, Beijing, China
| | - Yun Yuan
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Zhaoxia Wang
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Wei Sun
- Department of Neurology, Peking University First Hospital, Beijing, China
- *Correspondence: Wei Sun
| | - Haiqiang Jin
- Department of Neurology, Peking University First Hospital, Beijing, China
- Haiqiang Jin
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Zou Y, Luo H, Yuan H, Xie K, Yang Y, Huang S, Yang B, Liu Y. Identification of a Novel Nonsense Mutation in PLA2G6 and Prenatal Diagnosis in a Chinese Family With Infantile Neuroaxonal Dystrophy. Front Neurol 2022; 13:904027. [PMID: 35873758 PMCID: PMC9298276 DOI: 10.3389/fneur.2022.904027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 05/09/2022] [Indexed: 11/30/2022] Open
Abstract
Background and Purpose Infantile neuroaxonal dystrophy (INAD) is a subtype of PLA2G6-Associated Neurodegeneration (PLAN) with an age of early onset and severe clinical phenotypes of neurodegeneration. Individuals affected with INAD are characterized by rapid progressive psychomotor deterioration, neuroregression, and hypotonia followed by generalized spasticity, optic atrophy, and dementia. In this case, we aimed to identify the underlying causative genetic factors of a Chinese family with two siblings who presented with walking difficulty and inability to speak. We provided a prenatal diagnosis for the family and information for the prevention of this genetic disease. Methods Retrospective clinical information and magnetic resonance imaging (MRI) findings of the proband were collected. Trio-whole exome sequencing (WES) including the proband and his parents was performed to explore the genetic causes, while Sanger sequencing was subsequently used to validate the variants identified by Trio-WES in the pedigree. Furthermore, prenatal molecular genetic diagnosis was carried out through amniocentesis to investigate the status of pathogenic mutations in the fetus by Sanger sequencing at an appropriate gestational age. Results The two siblings were both clinically diagnosed with rapid regression in psychomotor development milestones. Brain MRI showed cerebellar atrophy and typical bilaterally symmetrical T2/FLAIR hyperintense signal changes in periventricular areas, indicating periventricular leukomalacia, and myelin sheath dysplasia. Trio-WES revealed two heterozygous variants in PlA2G6 associated with clinical manifestations in the proband: a novel maternally inherited variant c.217C>T (p.Gln73*) and a previously reported paternally inherited recurrent pathogenic variant c.1894C>T (p.Arg632Trp). These two heterozygous mutations were also detected in the younger brother who had similar clinical features as the proband. The novel variant c.217C>T was classified as “pathogenic (PVS1 + PM2 + PP3),” while the variant c.1894C>T was “pathogenic” (PS1 + PM1 + PM2 + PM3 + PP3) based on the latest American College of Medical Genetics and Genomics (ACMG) guidelines on sequence variants. Combining the molecular evidence and clinical phenotypes, the diagnosis of INAD was established for the two affected siblings. The two variants that were identified were considered the causative mutations for INAD in this family. Prenatal diagnosis suggested compound heterozygous mutations of c.217C>T and c.1894C>T in the fetus, indicating a high risk of INAD, and the parents chose to terminate the pregnancy. Conclusion We identified a novel pathogenic mutation that broadens the mutation spectrum of PLA2G6 and will provide clues for the molecular diagnosis of INAD. Furthermore, our study has helped to elucidate the causative genetic factors of this Chinese family with INAD effectively and efficiently by using the emerging Trio-WES strategy and providing precise genetic counseling for this family.
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Hanna Al-Shaikh R, Milanowski LM, Holla VV, Kurihara K, Yadav R, Kamble N, Muthusamy B, Bellad A, Koziorowski D, Szlufik S, Hoffman-Zacharska D, Fujioka S, Tsuboi Y, Ross OA, Wierenga K, Uitti RJ, Wszolek Z, Pal PK. PLA2G6-associated neurodegeneration in four different populations-case series and literature review. Parkinsonism Relat Disord 2022; 101:66-74. [PMID: 35803092 DOI: 10.1016/j.parkreldis.2022.06.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 06/17/2022] [Accepted: 06/20/2022] [Indexed: 11/30/2022]
Abstract
BACKGROUND PLA2G6-Associated Neurodegeneration, PLAN, is subdivided into: Infantile neuroaxonal dystrophy, atypical neuroaxonal dystrophy, and adult-onset dystonia parkinsonism [1]. It is elicited by a biallelic pathogenic variant in phospholipase A2 group VI (PLA2G6) gene. In this study we describe new cases and provide a comprehensive review of previously published cases. METHODS Eleven patients, from four different institutions and four different countries. All underwent a comprehensive chart review. RESULTS Ages at onset ranged from 1 to 36 years, with a median of 16 and a mean of 16.18 ± 11.91 years. Phenotypic characteristics were heterogenous and resembled that of patients with infantile neuroaxonal dystrophy (n = 2), atypical neuroaxonal dystrophy (n = 1), adult-onset dystonia parkinsonism (n = 1), complex hereditary spastic paraparesis (n = 3), and early onset Parkinson's disease (n = 2). Parental genetic studies were performed for all patients and confirmed with sanger sequencing in five. Visual evoked potential illustrated optic atrophy in P4. Mineralization was evident in brain magnetic resonance imaging of P1, P2, P4, P5, P7, and P11. Single photon emission computed tomography was conducted for three patients, revealed decreased perfusion in the occipital lobes for P10. DaTscan was performed for P11 and showed decreased uptake in the deep gray matter, bilateral caudate nuclei, and bilateral putamen. Positive response to Apomorphine was noted for P10 and to Baclofen in P2, and P3. CONCLUSIONS PLAN encompasses a wide clinical spectrum. Age and symptom at onset are crucial when classifying patients. Reporting new variants is critical to draw more attention to this condition and identify biomarkers to arrive at potential therapeutics.
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Affiliation(s)
| | - Lukasz M Milanowski
- Department of Neurology, Mayo Clinic, Jacksonville, FL, USA; Department of Neurology, Faculty of Health Science, Medical University of Warsaw, Warsaw, Poland
| | - Vikram V Holla
- Department of Neurology, National Institute of Mental Health & Neurosciences (NIMHANS), Bengaluru, India
| | | | - Ravi Yadav
- Department of Neurology, National Institute of Mental Health & Neurosciences (NIMHANS), Bengaluru, India
| | - Nitish Kamble
- Department of Neurology, National Institute of Mental Health & Neurosciences (NIMHANS), Bengaluru, India
| | - Babylakshmi Muthusamy
- Institute of Bioinformatics, Bengaluru, India; Manipal Academy of Higher Education, Manipal, India
| | - Anikha Bellad
- Institute of Bioinformatics, International Technology Park, Bangalore, 560066, India; Manipal Academy of Higher Education, Manipal, 576104, Karnataka, India
| | - Dariusz Koziorowski
- Department of Neurology, Faculty of Health Science, Medical University of Warsaw, Warsaw, Poland
| | - Stanislaw Szlufik
- Department of Neurology, Faculty of Health Science, Medical University of Warsaw, Warsaw, Poland
| | - Dorota Hoffman-Zacharska
- Department of Medical Genetics, Institute of Mother and Child, Warsaw, Poland; Institute of Genetics and Biotechnology, University of Warsaw, Warsaw, Poland
| | | | - Yoshio Tsuboi
- Department of Neurology, Fukuoka University, Fukuoka, Japan
| | - Owen A Ross
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA; Department of Clinical Genomics, Mayo Clinic, Jacksonville, FL, USA
| | - Klaas Wierenga
- Department of Clinical Genomics, Mayo Clinic, Jacksonville, FL, USA
| | - Ryan J Uitti
- Department of Neurology, Mayo Clinic, Jacksonville, FL, USA
| | | | - Pramod Kumar Pal
- Department of Neurology, National Institute of Mental Health & Neurosciences (NIMHANS), Bengaluru, India
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Toth-Bencsik R, Balicza P, Varga ET, Lengyel A, Rudas G, Gal A, Molnar MJ. New Insights of Phospholipase A2 Associated Neurodegeneration Phenotype Based on the Long-Term Follow-Up of a Large Hungarian Family. Front Genet 2021; 12:628904. [PMID: 34168672 PMCID: PMC8217829 DOI: 10.3389/fgene.2021.628904] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 04/06/2021] [Indexed: 11/13/2022] Open
Abstract
Introduction Phospholipase A2-associated Neurodegeneration (PLAN) is a group of neurodegenerative diseases associated with the alterations of PLA2G6. Some phenotype-genotype association are well known but there is no clear explanation why some cases can be classified into distinct subgroups, while others follow a continuous clinical spectrum. Methods Long-term neurological, and psychiatric follow-up, neuropathological, radiological, and genetic examinations, were performed in three affected girls and their family. Results Two 24-years old twins and their 22-years old sister harbored the p.P622S, and p.R600W mutation in PLA2G6. The age of onset and the most prominent presenting symptoms (gaze palsy, ataxia, dystonia, psychomotor regression indicated atypical neuroaxonal dystrophy (ANAD), however, optic atrophy, severe tetraparesis would fit into infantile neuroaxonal dystrophy (INAD). All siblings had hyperintensity in the globi pallidi and substantiae nigrae which is reported in ANAD, whereas it is considered a later neuroradiological marker in INAD. The slow progression, rigidity, bradykinesis, and the prominent psychiatric symptoms indicate PLA2G6-related dystonia-parkinsonism. Abnormal mitochondria, lipid accumulation and axonal spheroids were observed in the muscle and nerve tissue. Brain deposition appeared 6 years following the initial cerebellar atrophy. Mild MRI alterations were detected in the asymptomatic carrier parents. Conclusion The colorful clinical symptoms, the slightly discordant phenotype, and the neuroimaging data in the family supports the view that despite the distinct definition of age-related phenotypes in PLAN, these are not strict disease categories, but rather a continuous phenotypic spectrum. The mild MRI alterations of the parents and the family history suggest that even heterozygous pathogenic variants might be associated with clinical symptoms, although systematic study is needed to prove this.
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Affiliation(s)
- Renata Toth-Bencsik
- Institute of Genomic Medicine and Rare Disorders, Semmelweis University, Budapest, Hungary
| | - Peter Balicza
- Institute of Genomic Medicine and Rare Disorders, Semmelweis University, Budapest, Hungary
| | - Edina Timea Varga
- Department of Neurology, Albert Szent-Györgyi Medical and Pharmaceutical Center, University of Szeged, Szeged, Hungary
| | - Andras Lengyel
- Institute of Genomic Medicine and Rare Disorders, Semmelweis University, Budapest, Hungary
| | - Gabor Rudas
- MR Research Center, Semmelweis University, Budapest, Hungary
| | - Aniko Gal
- Institute of Genomic Medicine and Rare Disorders, Semmelweis University, Budapest, Hungary
| | - Maria Judit Molnar
- Institute of Genomic Medicine and Rare Disorders, Semmelweis University, Budapest, Hungary
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Agarwal P, Goswami JN. Siblings with Infantile Neuroaxonal Dystrophy. Journal of Pediatric Neurology 2021. [DOI: 10.1055/s-0040-1714093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
AbstractA 2 years 3 months male toddler with motor delay and his female sibling with history of marked global developmental regression following an intercurrent febrile illness were both noted to have phospholipase A2G6 (PLA2G6) mutation, confirming the diagnosis of infantile neuroaxonal dystrophy (INAD). This case report attempts to familiarize readers with the pleomorphic presentation of INAD and the role of early clinical identification, examination, and prompt genetic testing in establishing a diagnosis.
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Affiliation(s)
- Pulkit Agarwal
- Department of Pediatrics, Military Hospital, Ahmedabad, Gujarat, India
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Dangles MT, Malan V, Dumas G, Romana S, Raoul O, Coste-Zeitoun D, Soufflet C, Vignolo-Diard P, Bahi-Buisson N, Barnérias C, Chemaly N, Desguerre I, Gitiaux C, Hully M, Bourgeois M, Guimier A, Rio M, Munnich A, Nabbout R, Kaminska A, Eisermann M. Electro-clinical features in epileptic children with chromosome 15q duplication syndrome. Clin Neurophysiol 2021; 132:1126-1137. [PMID: 33773177 DOI: 10.1016/j.clinph.2021.02.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 02/03/2021] [Accepted: 02/22/2021] [Indexed: 11/25/2022]
Abstract
OBJECTIVE We aimed to describe epilepsy and EEG patterns related to vigilance states and age, in chromosome15-long-arm-duplication-syndrome (dup15q) children with epilepsy, in both duplication types: interstitial (intdup15) and isodicentric (idic15). METHODS Clinical data and 70 EEGs of 12 patients (5 intdup15, 7 idic15), followed from 4.5 m.o to 17y4m (median follow-up 8y3m), were retrospectively reviewed. EEGs were analyzed visually and using power spectrum analysis. RESULTS Seventy video-EEGs were analyzed (1-16 per patient, median 6), follow-up lasting up to 8y10m (median 4y2m): 25 EEGs in intdup15 (8 m.o to 12y.o, median 4y6m) and 45 EEGs in idic15 (7 m.o to 12 y.o, median 15 m). Epilepsy: 6 West syndrome (WS) (2intdup15, 4idic15); 4 Lennox-Gastaut syndromes (LGS) (1 intdup15, 3 idic15), 2 evolving from WS; focal epilepsy (3 intdup15). In idic15, WS displayed additional myoclonic seizures (3), atypical (4) or no hypsarrhythmia (2) and posterior predominant spike and polyspike bursts (4). Beta-band rapid-rhythms (RR): present in 11 patients, power decreased during non-REM-sleep, localization shifted from diffuse to anterior, peak frequency increased with age. CONCLUSION WS with peculiar electro-clinical features and LGS, along with beta-band RR decreasing in non-REM-sleep and shifting from diffuse to anterior localization with age are recognizable features pointing towards dup15q diagnosis in children with autism spectrum disorder and developmental delay. SIGNIFICANCE This study describes electroclinical features in both interstitial and isodicentric duplications of chromosome 15q, in epileptic children, including some recent extensions regarding sleep features; and illustrates how the temporo-spatial organization of beta oscillations can be of significant help in directing towards dup15q diagnosis hypothesis.
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Affiliation(s)
- M-T Dangles
- Department of Clinical Neurophysiology, Necker-Enfants-Malades Hospital, Assistance Publique -Hôpitaux de Paris, Paris, France; Centre de Référence des Epilepsies Rares CRéER, Department of Pediatric Neurology, Necker-Enfants-Malades Hospital, Assistance Publique -Hôpitaux de Paris, Paris, France; Department of Pediatric Neurology, Necker-Enfants-Malades Hospital, Assistance Publique -Hôpitaux de Paris, Paris, France; Université de Paris, Paris, France.
| | - V Malan
- Université de Paris, Paris, France; Department of Cytogenetics, Necker-Enfants-Malades Hospital, Assistance Publique -Hôpitaux de Paris, Paris, France
| | - G Dumas
- Department of Clinical Neurophysiology, Necker-Enfants-Malades Hospital, Assistance Publique -Hôpitaux de Paris, Paris, France; Human Genetics and Cognitive Functions, Institut Pasteur, UMR3571 CNRS, Université de Paris, Paris, France; Department of Psychiatry, Université de Montreal, CHU Sainte-Justine Hospital, Montreal, QC, Canada
| | - S Romana
- Université de Paris, Paris, France; Department of Cytogenetics, Necker-Enfants-Malades Hospital, Assistance Publique -Hôpitaux de Paris, Paris, France
| | - O Raoul
- Department of Cytogenetics, Necker-Enfants-Malades Hospital, Assistance Publique -Hôpitaux de Paris, Paris, France
| | - D Coste-Zeitoun
- Department of Clinical Neurophysiology, Necker-Enfants-Malades Hospital, Assistance Publique -Hôpitaux de Paris, Paris, France; Centre de Référence des Epilepsies Rares CRéER, Department of Pediatric Neurology, Necker-Enfants-Malades Hospital, Assistance Publique -Hôpitaux de Paris, Paris, France
| | - C Soufflet
- Department of Clinical Neurophysiology, Necker-Enfants-Malades Hospital, Assistance Publique -Hôpitaux de Paris, Paris, France
| | - P Vignolo-Diard
- Department of Clinical Neurophysiology, Necker-Enfants-Malades Hospital, Assistance Publique -Hôpitaux de Paris, Paris, France
| | - N Bahi-Buisson
- Department of Pediatric Neurology, Necker-Enfants-Malades Hospital, Assistance Publique -Hôpitaux de Paris, Paris, France; Université de Paris, Paris, France
| | - C Barnérias
- Department of Pediatric Neurology, Necker-Enfants-Malades Hospital, Assistance Publique -Hôpitaux de Paris, Paris, France
| | - N Chemaly
- Centre de Référence des Epilepsies Rares CRéER, Department of Pediatric Neurology, Necker-Enfants-Malades Hospital, Assistance Publique -Hôpitaux de Paris, Paris, France; Department of Pediatric Neurology, Necker-Enfants-Malades Hospital, Assistance Publique -Hôpitaux de Paris, Paris, France
| | - I Desguerre
- Department of Pediatric Neurology, Necker-Enfants-Malades Hospital, Assistance Publique -Hôpitaux de Paris, Paris, France; Université de Paris, Paris, France
| | - C Gitiaux
- Department of Clinical Neurophysiology, Necker-Enfants-Malades Hospital, Assistance Publique -Hôpitaux de Paris, Paris, France; Department of Pediatric Neurology, Necker-Enfants-Malades Hospital, Assistance Publique -Hôpitaux de Paris, Paris, France; Université de Paris, Paris, France
| | - M Hully
- Department of Pediatric Neurology, Necker-Enfants-Malades Hospital, Assistance Publique -Hôpitaux de Paris, Paris, France
| | - M Bourgeois
- Department of Pediatric Neurosurgery, Necker-Enfants-Malades Hospital, Assistance Publique -Hôpitaux de Paris, Paris, France
| | - A Guimier
- Department of Genetics, Necker-Enfants Malades Hospital, Assistance Publique -Hôpitaux de Paris, Paris, France
| | - M Rio
- Department of Genetics, Necker-Enfants Malades Hospital, Assistance Publique -Hôpitaux de Paris, Paris, France
| | - A Munnich
- Université de Paris, Paris, France; Department of Genetics, Necker-Enfants Malades Hospital, Assistance Publique -Hôpitaux de Paris, Paris, France
| | - R Nabbout
- Centre de Référence des Epilepsies Rares CRéER, Department of Pediatric Neurology, Necker-Enfants-Malades Hospital, Assistance Publique -Hôpitaux de Paris, Paris, France; Department of Pediatric Neurology, Necker-Enfants-Malades Hospital, Assistance Publique -Hôpitaux de Paris, Paris, France; Université de Paris, Paris, France
| | - A Kaminska
- Department of Clinical Neurophysiology, Necker-Enfants-Malades Hospital, Assistance Publique -Hôpitaux de Paris, Paris, France; Université de Paris, Paris, France
| | - M Eisermann
- Department of Clinical Neurophysiology, Necker-Enfants-Malades Hospital, Assistance Publique -Hôpitaux de Paris, Paris, France; Université de Paris, Paris, France
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Adams D, Midei M, Dastgir J, Flora C, Molinari RJ, Heerinckx F, Endemann S, Atwal P, Milner P, Shchepinov MS. Treatment of infantile neuroaxonal dystrophy with RT001: A di-deuterated ethyl ester of linoleic acid: Report of two cases. JIMD Rep 2020; 54:54-60. [PMID: 32685351 PMCID: PMC7358664 DOI: 10.1002/jmd2.12116] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 03/04/2020] [Accepted: 03/06/2020] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Infantile neuroaxonal dystrophy (INAD) is a rare, autosomal recessive disease due to defects in PLA2G6 and is associated with lipid peroxidation. RT001 is a di-deuterated form of linoleic acid that protects lipids from oxidative damage. METHODS We evaluated the pharmacokinetics (PK), safety, and effectiveness of RT001 in two subjects with INAD (subject 1: 34 months; subject 2: 10 months). After screening and baseline evaluations, subjects received 1.8 g of RT001 BD. PK analysis and clinical evaluations were made periodically. MAIN FINDINGS Plasma levels of deuterated linoleic acid (D2-LA), deuterated arachidonic acid (D2-AA), D2-LA to total LA, and D2-AA to total AA ratios were measured. The targeted plasma D2-LA ratio (>20%) was achieved by month 1 and maintained throughout the study. RBC AA-ratios were 0.11 and 0.18 at 6 months for subjects 1 and 2; respectively. No treatment-related adverse events occurred. Limited slowing of disease progression and some return of lost developmental milestones were seen. CONCLUSIONS Oral RT001 was administered safely in two subjects with INAD. Early findings suggest that the compound was well tolerated, metabolized and incorporated in the RBC membrane. A clinical trial is underway to assess efficacy.
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Affiliation(s)
- Darius Adams
- Atlantic Health SystemGoryeb Children's HospitalMorristownNew JerseyUSA
| | - Mark Midei
- Clinical DivisionRetrotope, Inc.Los AltosCaliforniaUSA
| | - Jahannaz Dastgir
- Atlantic Health SystemGoryeb Children's HospitalMorristownNew JerseyUSA
| | - Christina Flora
- Atlantic Health SystemGoryeb Children's HospitalMorristownNew JerseyUSA
| | | | | | | | - Paldeep Atwal
- Clinical DivisionRetrotope, Inc.Los AltosCaliforniaUSA
| | - Peter Milner
- Clinical DivisionRetrotope, Inc.Los AltosCaliforniaUSA
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10
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Altuame FD, Foskett G, Atwal PS, Endemann S, Midei M, Milner P, Salih MA, Hamad M, Al-Muhaizea M, Hashem M, Alkuraya FS. The natural history of infantile neuroaxonal dystrophy. Orphanet J Rare Dis 2020; 15:109. [PMID: 32357911 PMCID: PMC7193406 DOI: 10.1186/s13023-020-01355-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Accepted: 03/17/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Infantile neuroaxonal dystrophy (INAD) is a rapidly progressive neurodegenerative disorder of early onset causing premature death. It results from biallelic pathogenic variants in PLA2G6, which encodes a calcium-independent phospholipase A2. OBJECTIVE We aim to outline the natural history of INAD and provide a comprehensive description of its clinical, radiological, laboratory, and molecular findings. MATERIALS AND METHODS We comprehensively analyzed the charts of 28 patients: 16 patients from Riyadh, Saudi Arabia, 8 patients from North and South America and 4 patients from Europe with a molecularly confirmed diagnosis of PLA2G6-associated neurodegeneration (PLAN) and a clinical history consistent with INAD. RESULTS In our cohort, speech impairment and loss of gross motor milestones were the earliest signs of the disease. As the disease progressed, loss of fine motor milestones and bulbar dysfunction were observed. Temporo-frontal function was among the last of the milestones to be lost. Appendicular spastic hypertonia, axial hypotonia, and hyperreflexia were common neurological findings. Other common clinical findings include nystagmus (60.7%), seizures (42.9%), gastrointestinal disease (42.9%), skeletal deformities (35.7%), and strabismus (28.6%). Cerebellar atrophy and elevations in serum AST and LDH levels were consistent features of INAD. There was a statistically significant difference when comparing patients with non-sense/truncating variants compared with missense/in-frame deletions in the time of initial concern (p = 0.04), initial loss of language (p = 0.001), initial loss of fine motor skills (p = 0.009), and initial loss of bulbar skills (p = 0.007). CONCLUSION INAD is an ultra-rare neurodegenerative disorder that presents in early childhood, with a relentlessly progressive clinical course. Knowledge of the natural history of INAD may serve as a resource for healthcare providers to develop a targeted care plan and may facilitate the design of clinical trials to treat this disease.
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Affiliation(s)
- Fadie D Altuame
- College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | | | | | | | | | | | - Mustafa A Salih
- Division of Pediatric Neurology, Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Muddathir Hamad
- Division of Pediatric Neurology, Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Mohammad Al-Muhaizea
- Department of Neurosciences, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Mais Hashem
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Fowzan S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.
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11
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Guo YP, Tang BS, Guo JF. PLA2G6-Associated Neurodegeneration (PLAN): Review of Clinical Phenotypes and Genotypes. Front Neurol 2018; 9:1100. [PMID: 30619057 PMCID: PMC6305538 DOI: 10.3389/fneur.2018.01100] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 12/03/2018] [Indexed: 12/18/2022] Open
Abstract
Phospholipase A2 group VI (PLA2G6)-associated neurodegeneration (PLAN) includes a series of neurodegenerative diseases that result from the mutations in PLA2G6. PLAN has genetic and clinical heterogeneity, with different mutation sites, mutation types and ethnicities and its clinical phenotype is different. The clinical phenotypes and genotypes of PLAN are closely intertwined and vary widely. PLA2G6 encodes a group of VIA calcium-independent phospholipase A2 proteins (iPLA2β), an enzyme involved in lipid metabolism. According to the age of onset and progressive clinical features, PLAN can be classified into the following subtypes: infantile neuroaxonal dystrophy (INAD), atypical neuroaxonal dystrophy (ANAD) and parkinsonian syndrome which contains adult onset dystonia parkinsonism (DP) and autosomal recessive early-onset parkinsonism (AREP). In this review, we present an overview of PLA2G6-associated neurodegeneration in the context of current research.
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Affiliation(s)
- Yu-Pei Guo
- Center for Brain Disorders Research, Capital Medical University and Beijing Institute of Brain Disorders, Beijing, China.,Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Bei-Sha Tang
- Center for Brain Disorders Research, Capital Medical University and Beijing Institute of Brain Disorders, Beijing, China.,Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.,Center for Medical Genetics, Central South University, Changsha, China.,Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, China
| | - Ji-Feng Guo
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.,Center for Medical Genetics, Central South University, Changsha, China.,Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, China
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12
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Darling A, Aguilera-Albesa S, Tello CA, Serrano M, Tomás M, Camino-León R, Fernández-Ramos J, Jiménez-Escrig A, Poó P, O'Callaghan M, Ortez C, Nascimento A, Fernández Mesaque RC, Madruga M, Arrabal L, Roldan S, Gómez-Martín H, Garrido C, Temudo T, Jou-Muñoz C, Muchart J, Huisman TAGM, Poretti A, Lupo V, Espinós C, Pérez-Dueñas B. PLA2G6-associated neurodegeneration: New insights into brain abnormalities and disease progression. Parkinsonism Relat Disord 2018; 61:179-186. [PMID: 30340910 DOI: 10.1016/j.parkreldis.2018.10.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 09/19/2018] [Accepted: 10/12/2018] [Indexed: 11/30/2022]
Abstract
INTRODUCTION PLA2G6-associated neurodegeneration (PLAN) comprises a continuum of three phenotypes with overlapping clinical and radiologic features. METHODS Observational clinical study in a cohort of infantile and childhood onset PLAN patients and genetic analysis of the PLA2G6 gene. We analysed chronological evolution in terms of age at onset and disease course through a 66-item questionnaire. We performed qualitative and quantitative assessment of MRI abnormalities and searched for clinical and radiological phenotype and genotype correlations. RESULTS Sixteen PLAN patients (mean age: 10.2 years, range 3-33) were evaluated, with a median onset (years) of signs/symptoms as follows: neurological regression (1.5), oculomotor abnormalities (1.5), hypotonia (1.8), gait loss (2.2), pyramidal signs (3.0), axonal neuropathy (3.0), dysphagia (4.0), optic atrophy (4.0), psychiatric symptoms (4.0), seizures (5.9), joint contractures (6.0), dystonia (8.0), bladder dysfunction (13.0) and parkinsonism (15.0). MRI assessment identified cerebellar atrophy (19/19), brain iron deposition (10/19), clava hypertrophy (8/19) and T2/FLAIR hyperintensity of the cerebellar cortex (6/19). The mid-sagittal vermis relative diameter (MVRD) correlated with age at onset of clinical variants, meaning that the earlier the onset, the more severe the cerebellar atrophy. All patients harboured missense, nonsense and frameshift mutations in PLA2G6, including four novel variants. CONCLUSIONS Cerebellar atrophy was a universal radiological sign in infantile and childhood onset PLAN, and correlated with the severity of the phenotype. Iron accumulation within the globus pallidum and substantia nigra was also a common and strikingly uniform feature regardless of the phenotype.
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Affiliation(s)
- Alejandra Darling
- Pediatric Neurology Department, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain
| | - Sergio Aguilera-Albesa
- Pediatric Neurology Unit, Department of Pediatrics, Complejo Hospitalario de Navarra, Navarrabiomed, Pamplona, Spain
| | - Cristina Aisha Tello
- Unit of Genetics and Genomics of Neuromuscular and Neurodegenerative Disorders, Centro de Investigación Príncipe Felipe, Valencia, Spain
| | - Mercedes Serrano
- Neurology Department, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, CIBERER, Instituto de Salud Carlos III, Spain
| | - Miguel Tomás
- Pediatric Neurology Department, Hospital Universitario Politécnico La Fe, Valencia, Spain
| | - Rafael Camino-León
- Pediatric Neurology Department, Hospital Universitario Reina Sofía, Córdoba, Spain
| | | | | | - Pilar Poó
- Pediatric Neurology Department, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain
| | - Mar O'Callaghan
- Pediatric Neurology Department, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain
| | - Carlos Ortez
- Pediatric Neurology Department, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain
| | - Andrés Nascimento
- Pediatric Neurology Department, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain
| | | | - Marcos Madruga
- Pediatric Neurology Department, Hospital Universitario Virgen del Rocío, Sevilla, Spain
| | - Luisa Arrabal
- Pediatric Neurology Department, Hospital Virgen de las Nieves, Granada, Spain
| | - Susana Roldan
- Pediatric Neurology Department, Hospital Virgen de las Nieves, Granada, Spain
| | - Hilario Gómez-Martín
- Pediatric Neurology Department, Hospital San Pedro de Alcántara, Complejo Hospitalario Universitario de Cáceres, Spain
| | - Cristina Garrido
- Pediatric Neurology Department, Centro Materno-Infantil, Centro Hospitalario do Porto, Porto, Portugal
| | - Teresa Temudo
- Pediatric Neurology Department, Centro Materno-Infantil, Centro Hospitalario do Porto, Porto, Portugal
| | - Cristina Jou-Muñoz
- Pathology Department, Sant Joan de Déu Hospital, University of Barcelona, Barcelona, CIBERER, Instituto de Salud Carlos III, Spain
| | - Jordi Muchart
- Neuroradiology Department, Sant Joan de Déu Hospital, University of Barcelona, Barcelona, Spain
| | - Thierry A G M Huisman
- Division of Pediatric Radiology and Pediatric Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Andrea Poretti
- Division of Pediatric Radiology and Pediatric Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Vincenzo Lupo
- Unit of Genetics and Genomics of Neuromuscular and Neurodegenerative Disorders, Centro de Investigación Príncipe Felipe, Valencia, Spain
| | - Carmen Espinós
- Unit of Genetics and Genomics of Neuromuscular and Neurodegenerative Disorders, Centro de Investigación Príncipe Felipe, Valencia, Spain
| | - Belén Pérez-Dueñas
- Pediatric Neurology Department, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain; Pediatric Neurology Research Group, Vall d'Hebron Research Institute (VHIR), Universitat Autònoma de Barcelona, Barcelona, Catalonia, Spain.
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13
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Gitiaux C, Kaminska A, Boddaert N, Barcia G, Guéden S, The Tich SN, De Lonlay P, Quijano-Roy S, Hully M, Péréon Y, Desguerre I. PLA2G6-associated neurodegeneration: Lessons from neurophysiological findings. Eur J Paediatr Neurol 2018; 22:854-861. [PMID: 29859652 DOI: 10.1016/j.ejpn.2018.05.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2018] [Revised: 05/11/2018] [Accepted: 05/15/2018] [Indexed: 10/16/2022]
Abstract
BACKGROUND AND AIMS Phospholipase A2 associated neurodegeneration (PLAN) is a heterogeneous autosomal recessive disorder caused by mutations in the ubiquitously expressed PLA2G6 gene. It is responsible for delayed brain iron accumulation and induces progressive psychomotor regression. We report the concomitant clinical, radiological and neurophysiological findings in PLAN patients in an attempt to determine the contribution of each test to guide diagnosis. METHODS Concomitant clinical, radiological, electroencephalographic (EEG) and electrodiagnostic testing (EDX) findings in a series of 8 consecutive genetically confirmed PLAN patients were collected. RESULTS All patients presented marked motor axonal loss, with decreased or absent distal compound muscle action potentials, acute and chronic denervation at needle electromyography, in contrast with preservation of sensory conduction. EEG showed high-amplitude fast activity in all patients aged above 15 months. Two patients showing severe neonatal hypotonia displayed atypical hypsarhythmia and epileptic spasms. Iron deposition in globus pallidus was observed in only two patients aged above 6 years. CONCLUSIONS Peripheral involvement is an early feature in PLAN recognizable by EDX at an earlier stage than typical iron accumulation in the brain. Furthermore, the association of West syndrome and axonal motor neuropathy may represent positive clues in favor of PLAN. This results emphasize the interest of early and repeated EDX.
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Affiliation(s)
- Cyril Gitiaux
- Department of Clinical Pediatric Neurophysiology, AP-HP, Necker-Enfants Malades Hospital, Université Paris Descartes, Paris, France; Reference Center for Neuromuscular Diseases, FILNEMUS, Paris, France.
| | - Anna Kaminska
- Department of Clinical Pediatric Neurophysiology, AP-HP, Necker-Enfants Malades Hospital, Université Paris Descartes, Paris, France
| | - Nathalie Boddaert
- Department of Pediatric Radiology, Necker-Enfants Malades Hospital, AP-HP, Paris, France
| | - Giulia Barcia
- Unité INSERM U781, Université Paris Descartes, Département de génétique, Hôpital Necker Enfants Malades, AP-HP, Paris, France
| | - Sophie Guéden
- Department of Pediatric Neurology, CHU Angers, Angers, France
| | | | - Pascale De Lonlay
- Reference Center of Inherited Metabolic Diseases, Necker Enfants Malades Hospital, AP-HP, Imagine Institute, University Paris Descartes, Paris, France
| | | | - Marie Hully
- Department of Pediatric Neurology, Necker-Enfants Malades Hospital, AP-HP, Paris, France
| | - Yann Péréon
- Reference Centre for Neuromuscular Diseases Atlantique-Occitanie-Caraïbes, FILNEMUS, CHU Nantes, Nantes, France
| | - Isabelle Desguerre
- Reference Center for Neuromuscular Diseases, FILNEMUS, Paris, France; Department of Pediatric Neurology, Necker-Enfants Malades Hospital, AP-HP, Paris, France
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14
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Catania A, Battini R, Pippucci T, Pasquariello R, Chiapparini ML, Seri M, Garavaglia B, Zorzi G, Nardocci N, Ghezzi D, Tiranti V. R106C TFG variant causes infantile neuroaxonal dystrophy "plus" syndrome. Neurogenetics 2018; 19:179-87. [PMID: 29971521 DOI: 10.1007/s10048-018-0552-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 06/15/2018] [Indexed: 12/15/2022]
Abstract
TFG (tropomyosin-receptor kinase fused gene) encodes an essential protein in the regulation of vesicular trafficking between endoplasmic reticulum and Golgi apparatus. The homozygous variant c.316C > T within TFG has been previously associated with a complicated hereditary spastic paraplegia (HSP) phenotype in two unrelated Indian families. Here, we describe the first Italian family with two affected siblings harboring the same variant, who in childhood were classified as infantile neuroaxonal dystrophy (INAD) based on clinical and neuropathological findings. Twenty years after the first diagnosis, exome sequencing was instrumental to identify the genetic cause of this disorder and clinical follow-up of patients allowed us to reconstruct the natural history of this clinical entity. Investigations on patient's fibroblasts demonstrate the presence of altered mitochondrial network and inner membrane potential, associated with metabolic impairment. Our study highlights phenotypic heterogeneity characterizing individuals carrying the same pathogenic variant in TFG and provides an insight on tight connection linking mitochondrial efficiency and neuronal health to vesicular trafficking.
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15
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Iannello G, Graziano C, Cenacchi G, Cordelli DM, Zuntini R, Papa V, Magistà AM, Gagliardi M, Procopio R, Quattrone A, Annesi G. A new PLA2G6 mutation in a family with infantile neuroaxonal dystrophy. J Neurol Sci 2017; 381:209-212. [DOI: 10.1016/j.jns.2017.08.3260] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 07/14/2017] [Accepted: 08/24/2017] [Indexed: 11/17/2022]
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16
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Strokin M, Reiser G. Neurons and astrocytes in an infantile neuroaxonal dystrophy (INAD) mouse model show characteristic alterations in glutamate-induced Ca 2+ signaling. Neurochem Int 2017; 108:121-32. [DOI: 10.1016/j.neuint.2017.03.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2016] [Revised: 03/03/2017] [Accepted: 03/03/2017] [Indexed: 01/01/2023]
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17
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Iodice A, Spagnoli C, Salerno GG, Frattini D, Bertani G, Bergonzini P, Pisani F, Fusco C. Infantile neuroaxonal dystrophy and PLA2G6-associated neurodegeneration: An update for the diagnosis. Brain Dev 2017; 39:93-100. [PMID: 27884548 DOI: 10.1016/j.braindev.2016.08.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 08/29/2016] [Accepted: 08/30/2016] [Indexed: 11/25/2022]
Abstract
Infantile neuroaxonal dystrophy is a rare neurodegenerative disorder characterized by infantile onset of rapid motor and cognitive regression and hypotonia evolving into spasticity. Recessively inherited mutations of the PLA2G6 gene are causative of infantile neuroaxonal dystrophy and other PLA2G6-associated neurodegeneration, which includes conditions known as atypical neuroaxonal dystrophy, Karak syndrome and early-onset dystonia-parkinsonism with cognitive impairment. Phenotypic spectrum continues to evolve and genotype-phenotype correlations are currently limited. Due to the overlapping phenotypes and heterogeneity of clinical findings characterization of the syndrome is not always achievable. We reviewed the most recent clinical and neuroradiological information in the way to make easier differential diagnosis with other degenerative disorders in the paediatric age. Recognizing subtle signs and symptoms is a fascinating challenge to drive towards better diagnostic and genetic investigations.
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Affiliation(s)
- Alessandro Iodice
- Child Neurology Unit, Arcispedale Santa Maria Nuova Hospital - IRCCS, Reggio Emilia, Italy.
| | - Carlotta Spagnoli
- Child Neurology Unit, Arcispedale Santa Maria Nuova Hospital - IRCCS, Reggio Emilia, Italy
| | | | - Daniele Frattini
- Child Neurology Unit, Arcispedale Santa Maria Nuova Hospital - IRCCS, Reggio Emilia, Italy
| | - Gianna Bertani
- Child Neurology Unit, Arcispedale Santa Maria Nuova Hospital - IRCCS, Reggio Emilia, Italy
| | - Patrizia Bergonzini
- Pediatric Neurology Unit, Department of Mother & Child, University Hospital of Modena, Italy
| | - Francesco Pisani
- Child Neuropsychiatry Unit, Neuroscience Department, University of Parma, Italy
| | - Carlo Fusco
- Child Neurology Unit, Arcispedale Santa Maria Nuova Hospital - IRCCS, Reggio Emilia, Italy
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Abstract
Neurodegeneration with brain iron accumulation (NBIA) describes a heterogeneous group of inherited rare clinical and genetic entities. Clinical core symptoms comprise a combination of early-onset dystonia, pyramidal and extrapyramidal signs with ataxia, cognitive decline, behavioral abnormalities, and retinal and axonal neuropathy variably accompanying these core features. Increased nonphysiologic, nonaging-associated brain iron, most pronounced in the basal ganglia, is often termed the unifying characteristic of these clinically variable disorders, though occurrence and extent can be fluctuating or even absent. Neuropathologically, NBIA disorders usually are associated with widespread axonal spheroids and local iron accumulation in the basal ganglia. Postmortem, Lewy body, TDP-43, or tau pathology has been observed. Genetics have fostered ongoing progress in elucidating underlying pathophysiologic mechanisms of NBIA disorders. Ten associated genes have been established, with many more being suggested as new technologies and data emerge. Clinically, certain symptom combinations can suggest a specific genetic defect. Genetic tests, combined with postmortem neuropathology, usually make for the final disease confirmation. Despite these advances, treatment to date remains mainly symptomatic. This chapter reviews the established genetic defects leading to different NBIA subtypes, highlights phenotypic presentations to direct genetic testing, and briefly discusses the scarce available treatment options and upcoming challenges and future hopes of the field.
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Affiliation(s)
- Sarah Wiethoff
- UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, London, United Kingdom; Center for Neurology and Hertie Institute for Clinical Brain Research, Eberhard-Karls-University, Tübingen, Germany.
| | - Henry Houlden
- UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, London, United Kingdom.
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19
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Strokin M, Reiser G. Mitochondria from a mouse model of the human infantile neuroaxonal dystrophy (INAD) with genetic defects in VIA iPLA 2 have disturbed Ca 2+ regulation with reduction in Ca 2+ capacity. Neurochem Int 2016; 99:187-93. [DOI: 10.1016/j.neuint.2016.07.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 06/30/2016] [Accepted: 07/05/2016] [Indexed: 11/21/2022]
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Li H, Zou Y, Bao X, Wang H, Wang J, Jin H, Che Y, Tang X. Monozygotic twins with infantile neuroaxonal dystrophy: A case report and literature review. Exp Ther Med 2016; 12:3387-3389. [PMID: 27882168 DOI: 10.3892/etm.2016.3761] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 08/11/2016] [Indexed: 01/03/2023] Open
Abstract
Infantile neuroaxonal dystrophy (INAD) is a rare neurodegenerative disease with early onset. PLA2G6 gene mutations have been identified in the majority individuals with INAD. In future, molecular diagnosis of INAD will replace the invasive biopsies used previously. In the present report, monozygotic male twins with INAD were referred The Children's Hospital (Zhejiang University School of Medicine, Zhejiang, China) at fifteen months old for delayed development. The older brother was found to have developmental stagnation when he was 6 months old. The patient could not stand securely without support, and had poor eye tracking and listening ability. Magnetic resonance imaging (MRI) of the patient's brain revealed cerebellar atrophy and electromyography identified signs of peripheral neuropathy. The younger brother displayed similar clinical features and findings. Two different phospholipase A2 group VI (PLA2G6; 22q13.1) gene mutations were detected in the twins by DNA sequencing. The results of the present study indicate that neurogenetic disease should be considered when child patients present with idiopathic developmental stagnation, particularly when similar cases have appeared in the same family. In addition, INAD should be considered as a possible diagnosis when the patient has developmental delay of the central and peripheral nerves. In the future, molecular genetic testing will be the primary method of INAD diagnosis, enabling better prevention of this genetic disease.
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Affiliation(s)
- Haifeng Li
- Rehabilitation Department, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310051, P.R. China
| | - Yan Zou
- Nutrition and Food Safety Department, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, Zhejiang 310051, P.R. China
| | - Xinhua Bao
- Pediatric Department, Peking University First Hospital, Beijing 100034, P.R. China
| | - Hui Wang
- Rehabilitation Department, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310051, P.R. China
| | - Jiangping Wang
- Rehabilitation Department, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310051, P.R. China
| | - Huiying Jin
- Rehabilitation Department, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310051, P.R. China
| | - Yuping Che
- Rehabilitation Department, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310051, P.R. China
| | - Xiaoyan Tang
- Clinical Laboratory of Zhongke, Beijing 100034, P.R. China
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Al-Maawali A, Yoon G, Feigenbaum AS, Halliday WC, Clarke JTR, Branson HM, Banwell BL, Chitayat D, Blaser SI. Validation of the finding of hypertrophy of the clava in infantile neuroaxonal dystrophy/PLA2G6 by biometric analysis. Neuroradiology 2016; 58:1035-1042. [PMID: 27516098 DOI: 10.1007/s00234-016-1726-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 07/07/2016] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Infantile neuroaxonal dystrophy (INAD), an autosomal recessive neurodegenerative disorder due to PLA2G6 mutation, is classified both as a PLA2G6-associated neurodegeneration (PLAN) disorder and as one of the neurodegeneration with brain iron accumulation (NBIA) disorders. Age of onset and clinical presentation in INAD is variable. Typically described imaging features of cerebellar atrophy, cerebellar cortex bright FLAIR signal, and globus pallidus iron deposition are variable or late findings. We characterize clinical and neuroimaging phenotypes in nine children with confirmed PLA2G6 mutations and show a useful imaging feature, clava hypertrophy, which may aid in earlier identification of patients. Measurements of the clava confirm actual enlargement, rather than apparent enlargement due to volume loss of the other brain stem structures. METHODS A retrospective clinical and MRI review was performed. Brain stem measurements were performed and compared with age-matched controls. RESULTS We identified nine patients, all with novel PLA2G6 gene mutations. MRI, available in eight, showed clava hypertrophy, regardless of age or the absence of other more typically described neuroimaging findings. Brain autopsy in our cohort confirmed prominent spheroid bodies in the clava nuclei. CONCLUSION Clava hypertrophy is an important early imaging feature which may aid in indentification of children who would benefit from specific testing for PLA2G6 mutations.
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Affiliation(s)
- A Al-Maawali
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.,Department of Genetics, Sultan Qaboos University Hospital, Sultan Qaboos University, Muscat, Oman
| | - G Yoon
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.,Division of Neurology, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - A S Feigenbaum
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.,Division of Genetics, Department of Pediatrics, University of California, San Diego, La Jolla, CA, USA
| | - W C Halliday
- Division of Pathology, DPLM, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - J T R Clarke
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - H M Branson
- Division of Paediatric Neuroradiology, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, M5G 1X8, Ontario, Canada
| | - B L Banwell
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - D Chitayat
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.,The Prenatal Diagnosis and Medical Genetics Program, Department of Obstetrics and Gynecology, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Susan I Blaser
- Division of Paediatric Neuroradiology, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, M5G 1X8, Ontario, Canada.
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Kinghorn KJ, Castillo-Quan JI, Li L, Bhatia KP, Abramov AY, Hardy J, Partridge L. Reply: Glial mitochondropathy in infantile neuroaxonal dystrophy: pathophysiological and therapeutic implications. Brain 2016; 139:e68. [PMID: 27497489 DOI: 10.1093/brain/aww185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Kerri J Kinghorn
- 1 Institute of Healthy Ageing and Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK .,2 Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - Jorge Iván Castillo-Quan
- 1 Institute of Healthy Ageing and Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK.,2 Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - Li Li
- 1 Institute of Healthy Ageing and Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK
| | - Kailash P Bhatia
- 2 Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - Andrey Y Abramov
- 2 Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - John Hardy
- 2 Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - Linda Partridge
- 1 Institute of Healthy Ageing and Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK
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23
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Kinghorn KJ, Castillo-Quan JI. Mitochondrial dysfunction and defects in lipid homeostasis as therapeutic targets in neurodegeneration with brain iron accumulation. Rare Dis 2016; 4:e1128616. [PMID: 27141409 PMCID: PMC4838319 DOI: 10.1080/21675511.2015.1128616] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 11/11/2015] [Accepted: 12/01/2015] [Indexed: 10/26/2022] Open
Abstract
The PLA2G6 gene encodes a group VIA calcium independent phospholipase A2 (iPLA2β), which hydrolyses glycerophospholipids to release fatty acids and lysophospholipids. Mutations in PLA2G6 are associated with a number of neurodegenerative disorders including neurodegeneration with brain iron accumulation (NBIA), infantile neuroaxonal dystrophy (INAD), and dystonia parkinsonism, collectively known as PLA2G6-associated neurodegeneration (PLAN). Recently Kinghorn et al. demonstrated in Drosophila and PLA2G6 mutant fibroblasts that loss of normal PLA2G6 activity is associated with mitochondrial dysfunction and mitochondrial lipid peroxidation. Furthermore, they were able to show the beneficial effects of deuterated polyunsaturated fatty acids (D-PUFAs), which reduce lipid peroxidation. D-PUFAs were able to rescue the locomotor deficits of flies lacking the fly ortholog of PLA2G6 (iPLA2-VIA), as well as the mitochondrial abnormalities in PLA2G6 mutant fibroblasts. This work demonstrated that the iPLA2-VIA knockout fly is a useful organism to dissect the mechanisms of pathogenesis of PLAN, and that further investigation is required to determine the therapeutic potential of D-PUFAs in patients with PLA2G6 mutations. The fruit fly has also been used to study some of the other genetic causes of NBIA, and here we also describe what is known about the mechanisms of pathogenesis of these NBIA variants. Mitochondrial dysfunction, defects in lipid metabolism, as well as defective Coenzyme A (CoA) biosynthesis, have all been implicated in some genetic forms of NBIA, including PANK2, CoASY, C12orf19 and FA2H.
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Affiliation(s)
- Kerri J Kinghorn
- Institute of Healthy Ageing and Department of Genetics, Environment and Evolution, University College London, London, UK; Institute of Neurology, University College London, Queen Square, London, UK
| | - Jorge Iván Castillo-Quan
- Institute of Healthy Ageing and Department of Genetics, Environment and Evolution, University College London, London, UK; Institute of Neurology, University College London, Queen Square, London, UK
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Karkheiran S, Shahidi GA, Walker RH, Paisán-Ruiz C. PLA2G6-associated Dystonia-Parkinsonism: Case Report and Literature Review. Tremor Other Hyperkinet Mov (N Y) 2015. [PMID: 26196026 PMCID: PMC4503963 DOI: 10.7916/d84q7t4w] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Background Phospholipase-associated neurodegeneration (PLAN) caused by PLA2G6 mutations is a recessively inherited disorder with three known phenotypes: the typical infantile onset neuroaxonal dystrophy (INAD); an atypical later onset form (atypical NAD); and the more recently recognized young-onset dystonia–parkinsonism (PLAN-DP). Case Report We report the clinical, radiological, and genetic findings of a young Pakistani male with PLAN-DP. We review 11 previously published case reports cited in PubMed, and summarize the demographic, clinical, genetic, and radiological data of the 23 patients described in those articles. Discussion PLAN-DP presents with diverse motor, autonomic, and neuropsychiatric features and should be considered in the differential diagnosis of patients with young-onset neurodegenerative disorders.
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Affiliation(s)
- Siamak Karkheiran
- Movement Disorders Clinic, Hazrat Rasool Hospital, Iran University of Medical Sciences, Tehran, Iran
| | - Gholam Ali Shahidi
- Movement Disorders Clinic, Hazrat Rasool Hospital, Iran University of Medical Sciences, Tehran, Iran
| | - Ruth H Walker
- Department of Neurology, James J. Peters Veterans Affairs Medical Center, Bronx, NY, USA ; Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Coro Paisán-Ruiz
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, USA ; Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA ; Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA ; The Friedman Brain and The Mindich Child Health and Development Institutes, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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25
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Abstract
BACKGROUND Parkinson's disease (PD) was previously described as the prototypical sporadic disease; however, rapid advances in population and molecular genetics have revealed the existence of a significant number genetic risk factors, prompting its redefinition as a primarily genetic disorder. SOURCES OF DATA Data for this review have been gathered from the published literature. AREAS OF AGREEMENT Multiple haplotypes conveying variable but quantifiable genetic risk, acting concurrently and possibly interacting with one another, provide the basis for a new model of PD. The beginning of this revolution in our understanding came from the clinical observation of parkinsonism with a Mendelian pattern of inheritance in a number of families. The functional work that followed elucidated multiple disease pathways leading to the degeneration of the substantia nigra that characterizes PD. It is however only in recent years, with the emergence of large cohort genome-wide association studies (GWAS), that the relevance of these pathways to so-called sporadic PD has become apparent. AREAS OF CONTROVERSY A substantial portion of the presumed genetic inheritance of PD remains at present undefined. Although it is likely that so-called intermediate risk genetic risk factors are the principal component of this 'missing heritability', this is yet to be proved. GROWING POINTS Although the picture is by now means complete, the beginnings of rational basis for genetic screening of PD risk have begun to emerge. Equally, this enhanced understanding of the various genetic and in turn biochemical pathways shows promising signs of producing fruitful therapeutic strategies. Technological advances promise to reduce the costs associated with and further increase our capability to understand the complex influence of genetics on the pathogenesis of PD. AREAS TIMELY FOR DEVELOPING RESEARCH The coming years will require the enhancement of current techniques and the development of new ones to define PD's missing heritability. It will also require functional work to define better and in turn potentially reverse the mechanisms that contribute with large effect sizes to the risk of sporadic PD.
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Affiliation(s)
- Stephen Mullin
- Leonard Wolfson Clinical Research Fellow, UCL, Institute of Neurology, Rowland Hill Street, Hampstead, London NW3 2PF, UK
| | - Anthony Schapira
- Department of Clinical Neurosciences, UCL, Institute of Neurology, Hampstead, London, UK
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Frattini D, Nardocci N, Pascarella R, Panteghini C, Garavaglia B, Fusco C. Downbeat nystagmus as the presenting symptom of infantile neuroaxonal dystrophy: a case report. Brain Dev 2015; 37:270-2. [PMID: 24800972 DOI: 10.1016/j.braindev.2014.04.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Revised: 03/18/2014] [Accepted: 04/17/2014] [Indexed: 10/25/2022]
Abstract
Infantile neuroaxonal dystrophy is a rare neurodegenerative disorder characterized by infantile onset and rapid progression of psychomotor regression and hypotonia evolving into spasticity and dementia. Although nystagmus is a well-established neurological sign in infantile neuroaxonal dystrophy, it is mainly described as pendular and noticed in later stages of the disease. We report a 13-month-old girl with infantile neuroaxonal dystrophy harboring a compound heterozygous mutation in the PLA2G6 gene with downbeat nystagmus as the only presenting symptom. Our case indicates that downbeat nystagmus can be a rare but very early onset sign of cerebellar involvement in infantile neuroaxonal dystrophy and can anticipate the appearance of psychomotor regression and neuroradiological abnormalities.
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Affiliation(s)
- Daniele Frattini
- Pediatric Neurology Unit, Azienda Ospedaliera ASMN, Istituto e Cura a Carattere Scientifico, 42123 Reggio Emilia, Italy.
| | - Nardo Nardocci
- Child Neuropsychiatry Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy.
| | - Rosario Pascarella
- Neuroradiology Unit, Azienda Ospedaliera ASMN, Istituto e Cura a Carattere Scientifico, 42123 Reggio Emilia, Italy.
| | - Celeste Panteghini
- Molecular Neurogenetics Unit, Fondazione IRRCS Istituto Neurologico Carlo Besta, Milano, Italy.
| | - Barbara Garavaglia
- Molecular Neurogenetics Unit, Fondazione IRRCS Istituto Neurologico Carlo Besta, Milano, Italy.
| | - Carlo Fusco
- Pediatric Neurology Unit, Azienda Ospedaliera ASMN, Istituto e Cura a Carattere Scientifico, 42123 Reggio Emilia, Italy.
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27
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Abstract
Neurodegeneration with brain iron accumulation (NBIA) encompasses a group of inherited disorders that share the clinical features of an extrapyramidal movement disorder accompanied by varying degrees of intellectual disability and abnormal iron deposition in the basal ganglia. The genetic basis of ten forms of NBIA is now known. The clinical features of NBIA range from rapid global neurodevelopmental regression in infancy to mild parkinsonism with minimal cognitive impairment in adulthood, with wide variation seen between and within the specific NBIA sub-type. This review describes the clinical presentations, imaging findings, pathologic features, and treatment considerations for this heterogeneous group of disorders.
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Affiliation(s)
- Penelope Hogarth
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, OR, USA
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28
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Blanchard H, Taha AY, Cheon Y, Kim HW, Turk J, Rapoport SI. iPLA2β knockout mouse, a genetic model for progressive human motor disorders, develops age-related neuropathology. Neurochem Res 2014; 39:1522-32. [PMID: 24919816 DOI: 10.1007/s11064-014-1342-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Revised: 04/23/2014] [Accepted: 05/22/2014] [Indexed: 12/21/2022]
Abstract
Calcium-independent phospholipase A2 group VIa (iPLA2β) preferentially releases docosahexaenoic acid (DHA) from the sn-2 position of phospholipids. Mutations of its gene, PLA2G6, are found in patients with several progressive motor disorders, including Parkinson disease. At 4 months, PLA2G6 knockout mice (iPLA2β(-/-)) show minimal neuropathology but altered brain DHA metabolism. By 1 year, they develop motor disturbances, cerebellar neuronal loss, and striatal α-synuclein accumulation. We hypothesized that older iPLA2β(-/-) mice also would exhibit inflammatory and other neuropathological changes. Real-time polymerase chain reaction and Western blotting were performed on whole brain homogenate from 15 to 20-month old male iPLA2β(-/-) or wild-type (WT) mice. These older iPLA2β(-/-) mice compared with WT showed molecular evidence of microglial (CD-11b, iNOS) and astrocytic (glial fibrillary acidic protein) activation, disturbed expression of enzymes involved in arachidonic acid metabolism, loss of neuroprotective brain derived neurotrophic factor, and accumulation of cytokine TNF-α messenger ribonucleic acid, consistent with neuroinflammatory pathology. There was no evidence of synaptic loss, of reduced expression of dopamine active reuptake transporter, or of accumulation of the Parkinson disease markers Parkin or Pink1. iPLA2γ expression was unchanged. iPLA2β deficient mice show evidence of neuroinflammation and associated neuropathology with motor dysfunction in later life. These pathological biomarkers could be used to assess efficacy of dietary intervention, antioxidants or other therapies on disease progression in this mouse model of progressive human motor diseases associated with a PLA2G6 mutation.
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Bosch DGM, Boonstra FN, Willemsen MAAP, Cremers FPM, de Vries BBA. Low vision due to cerebral visual impairment: differentiating between acquired and genetic causes. BMC Ophthalmol 2014; 14:59. [PMID: 24886270 PMCID: PMC4021540 DOI: 10.1186/1471-2415-14-59] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Accepted: 04/28/2014] [Indexed: 11/21/2022] Open
Abstract
Background To gain more insight into genetic causes of cerebral visual impairment (CVI) in children and to compare ophthalmological findings between genetic and acquired forms of CVI. Methods The clinical data of 309 individuals (mainly children) with CVI, and a visual acuity ≤0.3 were analyzed for etiology and ocular variables. A differentiation was made between acquired and genetic causes. However, in persons with West syndrome or hydrocephalus, it might be impossible to unravel whether CVI is caused by the seizure disorder or increased intracranial pressure or by the underlying disorder (that in itself can be acquired or genetic). In two subgroups, individuals with ‘purely’ acquired CVI and with ‘purely’ genetic CVI, the ocular variables (such as strabismus, pale optic disc and visual field defects) were compared. Results It was possible to identify a putative cause for CVI in 60% (184/309) of the cohort. In the remaining 40% the etiology could not be determined. A ‘purely’ acquired cause was identified in 80 of the patients (26%). West syndrome and/or hydrocephalus was identified in 21 patients (7%), and in 17 patients (6%) both an acquired cause and West and/or hydrocephalus was present. In 66 patients (21%) a genetic diagnosis was obtained, of which 38 (12%) had other possible risk factor (acquired, preterm birth, West syndrome or hydrocephalus), making differentiation between acquired and genetic not possible. In the remaining 28 patients (9%) a ‘purely’ genetic cause was identified. CVI was identified for the first time in several genetic syndromes, such as ATR-X, Mowat-Wilson, and Pitt Hopkins syndrome. In the subgroup with ‘purely’ acquired causes (N = 80) strabismus (88% versus 64%), pale optic discs (65% versus 27%) and visual field defects (72% versus 30%) could be observed more frequent than in the subgroup with ‘purely’ genetic disorders (N = 28). Conclusions We conclude that CVI can be part of a genetic syndrome and that abnormal ocular findings are present more frequently in acquired forms of CVI.
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Affiliation(s)
| | | | | | | | - Bert B A de Vries
- Department of Human Genetics, Radboud University Medical Center, P,O, Box 9101, Nijmegen, HB 6500, The Netherlands.
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Solomons J, Ridgway O, Hardy C, Kurian MA, Jayawant S, Hughes S, Pretorius P, Németh AH, Németh AH. Infantile neuroaxonal dystrophy caused by uniparental disomy. Dev Med Child Neurol 2014; 56:386-9. [PMID: 24628589 DOI: 10.1111/dmcn.12327] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/14/2013] [Indexed: 11/29/2022]
Abstract
Infantile neuroaxonal dystrophy (INAD) is a rare autosomal recessive neurodegenerative disorder caused by mutations in the phospholipase A2 group 6 (Pla2G6) gene. Affected individuals usually present between the ages of 6 months and 2 years with rapid cognitive and motor regression and axial hypotonia. Gait disturbance, limb spasticity, cerebellar signs, and optic atrophy are other common features associated with INAD. Although magnetic resonance imaging (MRI) can sometimes contribute towards the diagnosis, the confirmation of INAD is by Pla2G6 gene analysis. In this case report, we describe the first individual (female) with INAD due to a combination of uniparental heterodisomy and isodisomy; we discuss the possible underlying mechanism and highlight the importance of parental carrier testing in accurately predicting the recurrence risk in these families. We also confirm the recent report of hypertrophy of the clava (also known as the 'gracile tubercle') as a useful MRI sign in INAD.
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Affiliation(s)
- Joyce Solomons
- Department of Clinical Genetics, Leicester Royal Infirmary, University Hospitals Leicester, UK; Department of Cancer Studies & Molecular Medicine, University of Leicester, Leicester, UK; Department of Clinical Genetics, Oxford University Hospitals NHS Trust, Oxford, UK
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Riku Y, Ikeuchi T, Yoshino H, Mimuro M, Mano K, Goto Y, Hattori N, Sobue G, Yoshida M. Extensive aggregation of α-synuclein and tau in juvenile-onset neuroaxonal dystrophy: an autopsied individual with a novel mutation in the PLA2G6 gene-splicing site. Acta Neuropathol Commun 2013; 1:12. [PMID: 24252552 PMCID: PMC3893443 DOI: 10.1186/2051-5960-1-12] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2013] [Accepted: 04/05/2013] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Infantile neuroaxonal dystrophy (INAD) is a rare autosomal-recessive neurodegenerative disorder. Patients with INAD usually show neurological symptoms with infant onset and die in childhood. Recently, it was reported that mutations in the PLA2G6 gene cause INAD, but neuropathological analysis of genetically confirmed individuals with neuroaxonal dystrophy has been limited. RESULTS Here, we report a Japanese individual with neuroaxonal dystrophy associated with compound heterozygous mutations in the PLA2G6 gene. A novel splice-site mutation resulting in skipping and missense mutations (p.R538C) in exon 9 was identified in the patient. This patient initially presented with cerebellar ataxia at the age of 3 years, which was followed by symptoms of mental retardation, extrapyramidal signs, and epileptic seizure. The patient survived until 20 years of age. Neuropathological findings were characterized by numerous axonal spheroids, brain iron deposition, cerebellar neuronal loss, phosphorylated alpha-synuclein-positive Lewy bodies (LBs), and phosphorylated-tau-positive neurofibrillary tangles. In particular, LB pathology exhibited a unique distribution with extremely severe cortical involvement. CONCLUSIONS Our results support a genetic clinical view that compound heterozygous mutations with potential residual protein function are associated with a relatively mild phenotype. Moreover, the severe LB pathology suggests that dysfunction of the PLA2G6 gene primarily contributes to LB formation.
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32
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Lamari F, Mochel F, Sedel F, Saudubray JM. Disorders of phospholipids, sphingolipids and fatty acids biosynthesis: toward a new category of inherited metabolic diseases. J Inherit Metab Dis 2013; 36:411-25. [PMID: 22814679 DOI: 10.1007/s10545-012-9509-7] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2012] [Revised: 05/29/2012] [Accepted: 06/12/2012] [Indexed: 12/29/2022]
Abstract
We wish to delineate a novel, and rapidly expanding, group of inborn errors of metabolism with neurological/muscular presentations: the defects in phospholipids, sphingolipids and long chain fatty acids biosynthesis. At least 14 disorders have been described so far. Clinical presentations are diverse but can be divided into (1) diseases of the central nervous system; (2) peripheral neuropathies; and (3) muscular/cardiac presentations. (1) Leukodystrophy and/or iron deposits in basal ganglia is a common feature of phospholipase A2 deficiency, fatty acid hydroxylase deficiency, and pantothenate kinase-associated neurodegeneration. Infantile epilepsy has been reported in GM3 synthetase deficiency. Spastic quadriplegia with ichthyosis and intellectual disability are the presenting signs of the elongase 4 deficiency and the Sjogren-Larsson syndrome caused by fatty aldehyde dehydrogenase deficiency. Spastic paraplegia and muscle wasting are also seen in patients with mutations in the neuropathy target esterase gene. (2) Peripheral neuropathy is a prominent feature in PHARC syndrome due to α/β-hydrolase 12 deficiency, and in hereditary sensory autonomic neuropathy type I due to serine palmitoyl-CoA transferase deficiency. (3) Muscular/cardiac presentations include recurrent myoglobinuria in phosphatidate phosphatase 1 (Lipin1) deficiency; cardiomyopathy and multivisceral involvement in Barth syndrome secondary to tafazzin mutations; congenital muscular dystrophy due to choline kinase deficiency, Sengers syndrome due to acylglycerol kinase deficiency and Chanarin Dorfman syndrome due to α/β- hydrolase 5 deficiency. These synthesis defects of complex lipid molecules stand at the frontier between classical inborn errors of metabolism and other genetic diseases involving the metabolism of structural proteins.
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Affiliation(s)
- F Lamari
- Neurometabolic Unit, Pitié-Salpêtrière Hospital, AP-HP & University Pierre and Marie Curie, Paris, France
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33
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Abstract
The Neuroaxonal Dystrophies (NADs) are a group of clinically and genetically heterogeneous neurodegenerative conditions. These disorders show the unique pathological feature of neuroaxonal dystrophy (NAD): axonal swelling (spheroids) localized throughout the central nervous and peripheral nervous systems. NADs are also morphologically characterized by iron accumulation in the basal ganglia; and are now included in the group of diseases called neurodegeneration with brain iron accumulation (NBIA). NADs comprise two main diseases: pantothenate-kinase associated neurodegeneration (PKAN) and infantile neuroaxonal dystrophy (INAD). PKAN in caused by mutation in the PANK-2 gene. In classic PKAN onset of disease is in the first decade and patients show dystonia, rigidity and dysarthria; course is progressive leading to loss of autonomous gait within 15 years. In atypical PKAN age at onset is later and progression slower. Psychiatric symptoms, obsessive-compulsive disorder, and tourettism may be prominent. In classic INAD patients present with psychomotor regression between 6 months-3 years, followed by neurological deterioration leading to tetraparesis, optic atrophy, and dementia. Atypical NAD refers to all patients who differ from the classical phenotype in term of age at onset and disease progression. Mutations in PLA2G6 gene are found both in classic and atypical INAD patients.
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Kurian MA, Hayflick SJ. Pantothenate kinase-associated neurodegeneration (PKAN) and PLA2G6-associated neurodegeneration (PLAN): review of two major neurodegeneration with brain iron accumulation (NBIA) phenotypes. Int Rev Neurobiol 2013; 110:49-71. [PMID: 24209433 PMCID: PMC6059649 DOI: 10.1016/b978-0-12-410502-7.00003-x] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Neurodegeneration with brain iron accumulation (NBIA) comprises a heterogeneous group of disorders characterized by the presence of radiologically discernible high brain iron, particularly within the basal ganglia. A number of childhood NBIA syndromes are described, of which two of the major subtypes are pantothenate kinase-associated neurodegeneration (PKAN) and PLA2G6-associated neurodegeneration (PLAN). PKAN and PLAN are autosomal recessive NBIA disorders due to mutations in PANK2 and PLA2G6, respectively. Presentation is usually in childhood, with features of neurological regression and motor dysfunction. In both PKAN and PLAN, a number of classical and atypical phenotypes are reported. In this chapter, we describe the clinical, radiological, and genetic features of these two disorders and also discuss the pathophysiological mechanisms postulated to play a role in disease pathogenesis.
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Affiliation(s)
- Manju A Kurian
- Neurosciences Unit, UCL-Institute of Child Health, London, United Kingdom; Department of Neurology, Great Ormond Street Hospital, London, United Kingdom.
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Zhang P, Gao Z, Jiang Y, Wang J, Zhang F, Wang S, Yang Y, Xiong H, Zhang Y, Bao X, Xiao J, Wu X, Wu Y. Follow-up study of 25 Chinese children with PLA2G6-associated neurodegeneration. Eur J Neurol 2012; 20:322-30. [PMID: 22934738 DOI: 10.1111/j.1468-1331.2012.03856.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Accepted: 07/12/2012] [Indexed: 12/27/2022]
Abstract
BACKGROUND To perform a follow-up of 25 Chinese children with gene-confirmed PLA2G6-associated neurodegeneration (PLAN). METHODS We recruited patients with infantile neuroaxonal dystrophy (INAD) according to the criteria proposed by Nardocci et al. Follow-up was conducted from 7 months to 8 years after the first visit. The PLA2G6 gene was sequenced, and copy number variation (CNV) was detected in patients with only one mutant allele and in mutation-negative patients. Patients with late-onset PLAN until 2012 were reviewed. RESULTS All patients with INAD exhibited rapid decline in motor and mental function, consistent with previous reports from other populations. Epileptic seizures occurred in 16.7%. One teenager with late-onset PLAN was diagnosed and followed up. The age of disease onset in published late-onset PLAN ranged between 18 months and 37 years. Initial presentations included gait instability (79.0%), mood/behavior changes (10.5%), dysarthria (5.26%) and cognitive deterioration (5.3%). Compared with INAD, cerebellar atrophy (42.1%) was less frequent in the late-onset cases, with cerebral atrophy more common (71.4%). Brain iron accumulation was seen in 52.6%. PLA2G6 mutations were identified by DNA sequencing in 92.3% of clinically diagnosed INAD cases and in the late-onset case. Twenty-seven different mutations were found, of which 13 were novel. No CNVs were detected. Maternal uniparental disomy was confirmed in one INAD case. CONCLUSIONS This is the largest report on PLAN in the Chinese population. We suggest that PLA2G6 should be screened in any patient exhibiting progressive gait disturbance, bradykinesia, dysarthria, tremors, mood/behavior changes or cognitive decline, especially when associated with cerebellar atrophy and/or iron accumulation and/or cerebral atrophy.
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Affiliation(s)
- P Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing
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Glynn P. Neuronal phospholipid deacylation is essential for axonal and synaptic integrity. Biochim Biophys Acta Mol Cell Biol Lipids 2012; 1831:633-41. [PMID: 22903185 DOI: 10.1016/j.bbalip.2012.07.023] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Revised: 07/20/2012] [Accepted: 07/31/2012] [Indexed: 12/24/2022]
Abstract
Recessively-inherited deficiency in the catalytic activity of calcium-independent phospholipase A2-beta (iPLA2β) and neuropathy target esterase (NTE) causes infantile neuroaxonal dystrophy and hereditary spastic paraplegia, respectively. Thus, these two related phospholipases have non-redundant functions that are essential for structural integrity of synapses and axons. Both enzymes are expressed in essentially all neurons and also have independent roles in glia. iPLA2β liberates sn-2 fatty acid and lysophospholipids from diacyl-phospholipids. Ca(2+)-calmodulin tonically-inhibits iPLA2β, but this can be alleviated by oleoyl-CoA. Together with fatty acyl-CoA-mediated conversion of lysophospholipid to diacyl-phospholipid this may regulate sn-2 fatty acyl composition of phospholipids. In the nervous system, iPLA2β is especially important for the turnover of polyunsaturated fatty acid-associated phospholipid at synapses. More information is required on the interplay between iPLA2β and iPLA2-gamma in deacylation of neuronal mitochondrial phospholipids. NTE reduces levels of phosphatidylcholine (PtdCho) by degrading it to glycerophosphocholine and two free fatty acids. The substrate for NTE may be nascent PtdCho complexed with a phospholipid-binding protein. Protein kinase A-mediated phosphorylation enhances PtdCho synthesis and may allow PtdCho accumulation by coordinate inhibition of NTE activity. NTE operates primarily at the endoplasmic reticulum in neuronal soma but is also present in axons. NTE-mediated PtdCho homeostasis facilitates membrane trafficking and this appears most critical for the integrity of axon terminals in the spinal cord and hippocampus. For maintenance of peripheral nerve axons, iPLA2β activity may be able to compensate for NTE-deficiency but not vice-versa. Whether agonists acting at neuronal receptors modulate the activity of either enzyme remains to be determined. This article is part of a Special Issue entitled Phospholipids and Phospholipid Metabolism.
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Affiliation(s)
- Paul Glynn
- Department of Cell Physiology & Pharmacology, Henry Wellcome Building, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK.
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Panteghini C, Zorzi G, Venco P, Dusi S, Reale C, Brunetti D, Chiapparini L, Zibordi F, Siegel B, Garavaglia B, Simonati A, Bertini E, Nardocci N, Tiranti V. C19orf12 and FA2H mutations are rare in Italian patients with neurodegeneration with brain iron accumulation. Semin Pediatr Neurol 2012; 19:75-81. [PMID: 22704260 DOI: 10.1016/j.spen.2012.03.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Neurodegeneration with brain iron accumulation (NBIA) defines a wide spectrum of clinical entities characterized by iron accumulation in specific regions of the brain, predominantly in the basal ganglia. We evaluated the presence of FA2H and C19orf12 mutations in a cohort of 46 Italian patients with early onset NBIA, which were negative for mutations in the PANK2 and PLA2G6 genes. Follow-up molecular genetic and in vitro analyses were then performed. We did not find any mutations in the FA2H gene, although we identified 3 patients carrying novel mutations in the C19orf12 gene. The recent discovery of new genes responsible for NBIA extends the spectrum of the genetic investigation now available for these disorders and makes it possible to delineate a clearer clinical-genetic classification of different forms of this syndrome. A large fraction of patients still remain without a molecular genetics diagnosis, suggesting that additional NBIA genes are still to be discovered.
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Affiliation(s)
- Celeste Panteghini
- Unit of Molecular Neurogenetics, Pierfranco and Luisa Mariani Center for the study of Mitochondrial Disorders in Children, IRCCS, Foundation Neurological Institute C. Besta, Milan, Italy
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Abstract
Neurodegeneration with brain iron accumulation (NBIA) includes a heterogeneous group of genetically defined disorders characterized by progressive extrapyramidal deterioration and iron accumulation in the basal ganglia. Current medical options for these disorders remain largely unsatisfactory and do not prevent the disease from progressing to a severe and disabling state. In select cases, surgical techniques, such as deep brain stimulation, may be effective in ameliorating some of the symptoms of the disease. The availability of chelating agents with specific properties that have been demonstrated to be effective in other disorders with regional iron accumulation as well as magnetic resonance imaging techniques that allow for quantitative assessment of iron have stimulated interest in the use of chelating agents in NBIA. This review aims to describe the role of surgical therapies in NBIA, discuss the use of chelating agents in NBIA, and presents new therapeutic approaches under consideration.
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Strokin M, Seburn KL, Cox GA, Martens KA, Reiser G. Severe disturbance in the Ca2+ signaling in astrocytes from mouse models of human infantile neuroaxonal dystrophy with mutated Pla2g6. Hum Mol Genet 2012; 21:2807-14. [PMID: 22442204 DOI: 10.1093/hmg/dds108] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Infantile neuroaxonal dystrophy (INAD; OMIM #no. 256600) is an inherited degenerative nervous system disorder characterized by nerve abnormalities in brain, spinal cord and peripheral nerves. About 85% of INAD patients carry mutations in the PLA2G6 gene that encodes for a Ca(2+)-independent phospholipase A(2) (VIA iPLA(2)), but how these mutations lead to disease is unknown. Besides regulating phospholipid homeostasis, VIA iPLA(2) is emerging with additional non-canonical functions, such as modulating store-regulated Ca(2+) entry into cells, and mitochondrial functions. In turn, defective Ca(2+) regulation could contribute to the development of INAD. Here, we studied possible changes in ATP-induced Ca(2+) signaling in astrocytes derived from two mutant strains of mice. The first strain carries a hypomorphic allele of the Pla2g6 that reduces transcript levels to 5-10% of that observed in wild-type mice. The second strain carries a point mutation in Pla2g6 that results in inactive VIA iPLA(2) protein with postulated gain in toxicity. Homozygous mice from both strains develop pathology analogous to that observed in INAD patients. The nucleotide ATP is the most important transmitter inducing Ca(2+) signals in astroglial networks. We demonstrate here a severe disturbance in Ca(2+) responses to ATP in astrocytes derived from both mutant mouse strains. The duration of the Ca(2+) responses in mutant astrocytes was significantly reduced when compared with values observed in control cells. We also show that the reduced Ca(2+) responses are probably due to a reduction in capacitative Ca(2+) entry (2.3-fold). Results suggest that altered Ca(2+) signaling could be a central mechanism in the development of INAD pathology.
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Affiliation(s)
- Mikhail Strokin
- Institut für Neurobiochemie, Medizinische Fakultät, Otto-von-Guericke-Universität Magdeburg, Magdeburg, Germany
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Zhao Z, Wang J, Zhao C, Bi W, Yue Z, Ma ZA. Genetic ablation of PLA2G6 in mice leads to cerebellar atrophy characterized by Purkinje cell loss and glial cell activation. PLoS One 2011; 6:e26991. [PMID: 22046428 PMCID: PMC3203935 DOI: 10.1371/journal.pone.0026991] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Accepted: 10/07/2011] [Indexed: 12/15/2022] Open
Abstract
Infantile neuroaxonal dystrophy (INAD) is a progressive, autosomal recessive neurodegenerative disease characterized by axonal dystrophy, abnormal iron deposition and cerebellar atrophy. This disease was recently mapped to PLA2G6, which encodes group VI Ca(2+)-independent phospholipase A(2) (iPLA(2) or iPLA(2)β). Here we show that genetic ablation of PLA2G6 in mice (iPLA(2)β(-/-)) leads to the development of cerebellar atrophy by the age of 13 months. Atrophied cerebella exhibited significant loss of Purkinje cells, as well as reactive astrogliosis, the activation of microglial cells, and the pronounced up-regulation of the pro-inflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β). Moreover, glial cell activation and the elevation in TNF-α and IL-1β expression occurred before apparent cerebellar atrophy. Our findings indicate that the absence of PLA2G6 causes neuroinflammation and Purkinje cell loss and ultimately leads to cerebellar atrophy. Our study suggests that iPLA(2)β(-/-) mice are a valuable model for cerebellar atrophy in INAD and that early anti-inflammatory therapy may help slow the progression of cerebellar atrophy in this deadly neurodegenerative disease.
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Affiliation(s)
- Zhengshan Zhao
- Division of Experimental Diabetes and Aging, Department of Geriatrics and Palliative Medicine, Mount Sinai School of Medicine, New York, New York, United States of America
| | - Jing Wang
- Department of Neurology, Mount Sinai School of Medicine, New York, New York, United States of America
| | - Chunying Zhao
- Division of Experimental Diabetes and Aging, Department of Geriatrics and Palliative Medicine, Mount Sinai School of Medicine, New York, New York, United States of America
| | - Weina Bi
- Division of Experimental Diabetes and Aging, Department of Geriatrics and Palliative Medicine, Mount Sinai School of Medicine, New York, New York, United States of America
| | - Zhenyu Yue
- Department of Neurology, Mount Sinai School of Medicine, New York, New York, United States of America
| | - Zhongmin Alex Ma
- Division of Experimental Diabetes and Aging, Department of Geriatrics and Palliative Medicine, Mount Sinai School of Medicine, New York, New York, United States of America
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Beck G, Sugiura Y, Shinzawa K, Kato S, Setou M, Tsujimoto Y, Sakoda S, Sumi-Akamaru H. Neuroaxonal dystrophy in calcium-independent phospholipase A2β deficiency results from insufficient remodeling and degeneration of mitochondrial and presynaptic membranes. J Neurosci 2011; 31:11411-20. [PMID: 21813701 DOI: 10.1523/JNEUROSCI.0345-11.2011] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Infantile neuroaxonal dystrophy (INAD) is a fatal neurodegenerative disease characterized by the widespread presence of axonal swellings (spheroids) in the CNS and PNS and is caused by gene abnormality in PLA2G6 [calcium-independent phospholipase A(2)β (iPLA(2)β)], which is essential for remodeling of membrane phospholipids. To clarify the pathomechanism of INAD, we pathologically analyzed the spinal cords and sciatic nerves of iPLA(2)β knock-out (KO) mice, a model of INAD. At 15 weeks (preclinical stage), periodic acid-Schiff (PAS)-positive granules were frequently observed in proximal axons and the perinuclear space of large neurons, and these were strongly positive for a marker of the mitochondrial outer membrane and negative for a marker of the inner membrane. By 100 weeks (late clinical stage), PAS-positive granules and spheroids had increased significantly in the distal parts of axons, and ultrastructural examination revealed that these granules were, in fact, mitochondria with degenerative inner membranes. Collapse of mitochondria in axons was accompanied by focal disappearance of the cytoskeleton. Partial membrane loss at axon terminals was also evident, accompanied by degenerative membranes in the same areas. Imaging mass spectrometry showed a prominent increase of docosahexaenoic acid-containing phosphatidylcholine in the gray matter, suggesting insufficient membrane remodeling in the presence of iPLA(2)β deficiency. Prominent axonal degeneration in neuroaxonal dystrophy might be explained by the collapse of abnormal mitochondria after axonal transportation. Insufficient remodeling and degeneration of mitochondrial inner membranes and presynaptic membranes appear to be the cause of the neuroaxonal dystrophy in iPLA(2)β-KO mice.
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García-Cazorla A, Ortez C, Pérez-Dueñas B, Serrano M, Pineda M, Campistol J, Fernández-Álvarez E. Hypokinetic-rigid syndrome in children and inborn errors of metabolism. Eur J Paediatr Neurol 2011; 15:295-302. [PMID: 21612960 DOI: 10.1016/j.ejpn.2011.04.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Accepted: 04/22/2011] [Indexed: 11/24/2022]
Abstract
Hypokinetic-rigid syndrome (HRS) or "parkinsonism" is rare in children. From a clinical point of view it is characterised by a group of signs in which hypokinesia (decreased number of movements), bradykinesia (slowness of movements), rigidity and rest tremor are the fundamental traits. Nervous system infections, immunomediated encephalitis, hypoxia and some drugs have been described as acquired or secondary causes of HRS in the paediatric age. Inborn errors of metabolism (IEM) comprise and important group regarding genetic causes. Main diseases causing HRS in children are neurotransmitter (biogenic amines) defects, metal storage diseases, energy metabolism disorders and lysosomal diseases. In general, in IEM, the HRS is associated to other neurological signs such as dykinesias, pyramidal signs, and psychomotor delay, is very rare in the neonatal period, tends to be more frequent in advanced stages of progressive diseases, and may respond to specific therapies. In particular, l-dopa + carbidopa can be a very effective treatment in neurotransmitter defects, whereas other disorders such as Wilson disease and some particular lysosomal disorders have different therapeutic possibilities. Furthermore, other genetic conditions in dopa-responsive and non-responsive HRS should be also considered, especially in juvenile parkinsonism. Through this review, a practical orientation for paediatric neurologists concerning clinical clues, diagnostic procedure and treatment of metabolic HRS will be provided.
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Affiliation(s)
- A García-Cazorla
- Department of Neurology, Hospital Sant Joan de Déu, Passeig Sant Joan de Deu 2, 08950 Esplugues, Barcelona, Spain
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Abstract
Neurodegeneration with brain iron accumulation (NBIA) comprises a heterogeneous group of progressive complex motor disorders characterized by the presence of high brain iron, particularly within the basal ganglia. A number of autosomal recessive NBIA syndromes can present in childhood, most commonly pantothenate kinase-associated neurodegeneration (PKAN; due to mutations in the PANK2 gene) and phospholipase A2 group 6-associated neurodegeneration (PLAN; associated with genetic defects in PLA2G6). Mutations in the genes that cause these two neuroaxonal dystrophies are thought to disrupt the normal cellular functions of phospholipid remodelling and fatty acid metabolism. A significant proportion of children with an NBIA phenotype have no genetic diagnosis and there are, no doubt, additional as yet undiscovered genes that account for a number of these cases. NBIA disorders can be diagnostically challenging as there is often phenotypic overlap between the different disease entities. This review aims to define the clinical, radiological, and genetic features of such disorders, providing the clinician with a stepwise approach to appropriate neurological and genetic investigation, as well as a clinical management strategy for these neurodegenerative syndromes.
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Affiliation(s)
- Manju A Kurian
- Neurosciences Unit, Institute of Child Health (University College London) and Great Ormond Street Hospital, London, UK.
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Bernardi B, Pini A, Santucci M, Cenacchi C, Garavaglia B, Ucchino V, Garrone C, Guerra A, Faggioli R, Barzaghi C, Preda P, Franzoni E, Gobbi G, Parmeggiani A. MRI Findings in Patients with Clinical Onset Consistent with Infantile Neuroaxonal Dystrophy (INAD), Literature Review, Clinical and MRI Follow-up. Neuroradiol J 2011; 24:202-14. [DOI: 10.1177/197140091102400207] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Accepted: 01/03/2011] [Indexed: 11/17/2022] Open
Abstract
Infantile neuroaxonal dystrophy (INAD) is a rare autosomal recessive neurodegenerative disorder characterized by infantile onset and rapid progression of psychomotor regression and hypotonia evolving into spasticity. The neuroradiologic hallmark of the disease is represented by progressive cerebellar atrophy. Prior to the discovery of mutations in the PLA2G6 gene in family with INAD, the clinical diagnosis of the disease had been confirmed by the presence of spheroid bodies (SB) in a peripheral nerve biopsy. Various studies have found that some patients with mutations lacked SB and some without mutations had SB, indicating incomplete detection using either pathologic or molecular methods 7. This, together with the observation that the spectrum of clinical features associated with mutations in PLA2G6 is broader than previously described, has increased the usefulness of Magnetic Resonance (MR) in INAD diagnosis, particularly in the frequent occurrence of atypical cases, especially in the early stages of the disease. We retrospectively reviewed the MR studies of eight patients in whom clinical and imaging onset met the typical criteria for INAD. Their clinical and MR imaging (MRI) onset and follow-up were evaluated together with the neuroradiological findings reported in the literature in order to identify MRI features useful in differentiating INAD from other diseases with similar clinical onset and to discuss which of them are the most important, thus suggesting INAD diagnosis. Our contribution included the use of Proton Spectroscopy (1H-MR), diffusion weighted MR imaging (DWI) and diffusion tensor imaging (DTI) in the follow-up of seven of the eight patients. The literature reviewed included attempts to correlate clinical and MR data with the genotype in the group of patients carrying PLA2G6 mutations. From the limited and inhomogeneous cohort of patients included in our study, a correlation between the MR features, phenotype and genotype was not exhaustive.
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Affiliation(s)
- B. Bernardi
- Paediatric Neuroradiology Unit, Department of Neurosciences; Bologna, Italy
| | - A. Pini
- Child Neurology and Psychiatry Unit, Maggiore Hospital; Bologna, Italy
| | - M. Santucci
- Child Neurology and Psychiatry Unit, Department of Neurological Sciences, University of Bologna; Bologna, Italy
| | - C. Cenacchi
- Clinical Department of Radiological and Histopathological Sciences, University of Bologna; Bologna, Italy
| | - B. Garavaglia
- Movement Disorders and Energetic Metabolism Diseases, IRCCS Foundation Neurological Institute C. Besta; Milano, Italy
| | - V. Ucchino
- Paediatric Neuroradiology Unit, Department of Neurosciences; Bologna, Italy
| | - C. Garrone
- Child Neurology and Psychiatry Unit, S. Orsola Hospital; Bologna, Italy
| | - A. Guerra
- Paediatric Neurology, Policlinico Hospital; Modena, Italy
| | - R. Faggioli
- Paediatric Neurology, S. Anna Hospital; Ferrara, Italy
| | - C. Barzaghi
- Movement Disorders and Energetic Metabolism Diseases, IRCCS Foundation Neurological Institute C. Besta; Milano, Italy
| | - P. Preda
- Clinical Department of Radiological and Histopathological Sciences, University of Bologna; Bologna, Italy
| | - E. Franzoni
- Child Neurology and Psychiatry Unit, S. Orsola Hospital; Bologna, Italy
| | - G. Gobbi
- Child Neurology and Psychiatry Unit, Maggiore Hospital; Bologna, Italy
| | - A. Parmeggiani
- Child Neurology and Psychiatry Unit, Department of Neurological Sciences, University of Bologna; Bologna, Italy
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Polster B, Crosier M, Lindsay S, Hayflick S. Expression of PLA2G6 in human fetal development: Implications for infantile neuroaxonal dystrophy. Brain Res Bull 2010; 83:374-9. [PMID: 20813170 DOI: 10.1016/j.brainresbull.2010.08.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2010] [Revised: 08/17/2010] [Accepted: 08/24/2010] [Indexed: 12/22/2022]
Abstract
Mutations in PLA2G6, which encodes calcium-independent phospholipase A(2) group VIA (iPLA2-VIA), underlie the autosomal recessive disorder infantile neuroaxonal dystrophy (INAD). INAD typically presents in the first year of life, and leads to optic atrophy and psychomotor regression. We have examined PLA2G6 expression in early human embryonic development by in situ hybridization. At Carnegie Stage (CS) 19 (approximately 7 post-conception weeks [PCW]), strong expression is evident in the ventricular zone (VZ) of midbrain and forebrain suggestive of expression in neural stem and progenitor cells. At CS23 (8PCW) expression is also detectable in the VZ of the hindbrain and the subventricular zone (SVZ) of the developing neocortex, ganglionic eminences and diencephalon. By 9PCW strong expression in the post-mitotic cells of the cortical plate can be seen in the developing neocortex. In the eye, expression is seen in the lens and retina at all stages examined. PLA2G6 expression is also evident in the alar plate of the spinal cord, dorsal root ganglia, the retina and lens in the eye and several non-neuronal tissues, including developing bones, lung, kidney and gut. These findings suggest a role for PLA2G6 in neuronal proliferation throughout the developing brain and in maturing neurons in the cortical plate and hindbrain. Although widespread PLA2G6 expression is detected in neuronal tissues, the pattern shows dynamic changes with time and indicates that INAD pathogenesis may begin prior to birth.
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Affiliation(s)
- Brenda Polster
- Molecular and Medical Genetics, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd., Portland, OR 97239, United States.
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Crompton D, Rehal PK, MacPherson L, Foster K, Lunt P, Hughes I, Brady AF, Pike MG, De Gressi S, Morgan NV, Hardy C, Smith M, MacDonald F, Maher ER, Kurian MA. Multiplex ligation-dependent probe amplification (MLPA) analysis is an effective tool for the detection of novel intragenic PLA2G6 mutations: implications for molecular diagnosis. Mol Genet Metab 2010; 100:207-12. [PMID: 20226704 DOI: 10.1016/j.ymgme.2010.02.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2009] [Revised: 02/10/2010] [Accepted: 02/10/2010] [Indexed: 11/20/2022]
Abstract
Phospholipase associated neurodegeneration (PLAN) comprises a heterogeneous group of autosomal recessive neurological disorders caused by mutations in the PLA2G6 gene. Direct gene sequencing detects approximately 85% mutations in infantile neuroaxonal dystrophy. We report the novel use of multiplex ligation-dependent probe amplification (MLPA) analysis to detect novel PLA2G6 duplications and deletions. The identification of such copy number variants (CNVs) expands the PLAN mutation spectrum and may account for up to 12.5% of PLA2G6 mutations. MLPA should thus be employed to detect CNVs of PLA2G6 in patients who show clinical features of PLAN but in whom both disease-causing mutations cannot be identified on routine sequencing.
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Affiliation(s)
- Danielle Crompton
- West Midlands Regional Genetic Service, Birmingham Women's Hospital, Metchley Park Lane, Birmingham, UK
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Tonelli A, Romaniello R, Grasso R, Cavallini A, Righini A, Bresolin N, Borgatti R, Bassi MT. Novel splice-site mutations and a large intragenic deletion inPLA2G6associated with a severe and rapidly progressive form of infantile neuroaxonal dystrophy. Clin Genet 2010; 78:432-40. [DOI: 10.1111/j.1399-0004.2010.01417.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Wada H, Yasuda T, Miura I, Watabe K, Sawa C, Kamijuku H, Kojo S, Taniguchi M, Nishino I, Wakana S, Yoshida H, Seino KI. Establishment of an improved mouse model for infantile neuroaxonal dystrophy that shows early disease onset and bears a point mutation in Pla2g6. Am J Pathol 2009; 175:2257-63. [PMID: 19893029 DOI: 10.2353/ajpath.2009.090343] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Calcium-independent group VIA phospholipase A(2) (iPLA(2)beta), encoded by PLA2G6, has been shown to be involved in various physiological and pathological processes, including immunity, cell death, and cell membrane homeostasis. Mutations in the PLA2G6 gene have been recently identified in patients with infantile neuroaxonal dystrophy (INAD). Subsequently, it was reported that similar neurological impairment occurs in gene-targeted mice with a null mutation of iPLA(2)beta, whose disease onset became apparent approximately 1 to 2 years after birth. Here, we report the establishment of an improved mouse model for INAD that bears a point mutation in the ankyrin repeat domain of Pla2g6 generated by N-ethyl-N-nitrosourea mutagenesis. These mutant mice developed severe motor dysfunction, including abnormal gait and poor performance in the hanging grip test, as early as 7 to 8 weeks of age, in a manner following Mendelian law. Neuropathological examination revealed widespread formation of spheroids containing tubulovesicular membranes similar to human INAD. Molecular and biochemical analysis revealed that the mutant mice expressed Pla2g6 mRNA and protein, but the mutated Pla2g6 protein had no glycerophospholipid-catalyzing enzyme activity. Because of the significantly early onset of the disease, this mouse mutant (Pla2g6-inad) could be highly useful for further studies of pathogenesis and experimental interventions in INAD and neurodegeneration.
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Affiliation(s)
- Haruka Wada
- Division of Bioregulation Research, Institute of Medical Science, St. Marianna University School of Medicine, Kawasaki-City, Kanagawa, Japan
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Abstract
The enzyme neuropathy target esterase (NTE) is present in neurons and deacylates the major membrane phospholipid, phosphatidylcholine (PtdCho). Mutation of the NTE gene or poisoning by neuropathic organophosphates--chemical inhibitors of NTE--causes distal degeneration of long spinal axons in humans. However, analogous neuropathological changes have not been reported in nestin-cre:NTEfl/fl mice with NTE-deficient neural tissue. Furthermore, altered PtdCho homeostasis has not been detected in NTE-deficient vertebrates. Here, we describe distal degeneration of the longest spinal axons in approximately 3-week-old nestin-cre:NTEfl/fl mice and in adult C57BL/6J mice after acute dosing with a neuropathic organophosphate: in both groups early degenerative lesions were followed by swellings comprising accumulated axoplasmic material. In mice dosed acutely with organophosphate, maximal numbers of lesions, in the longest spinal sensory axon tract, were attained within days and were preceded by a transient rise in neural PtdCho. In nestin-cre:NTEfl/fl mice, sustained elevation of PtdCho over many months was accompanied by progressive degeneration and massive swelling of axons in sensory and motor spinal tracts and by increasing hindlimb dysfunction. Axonal lesion distribution closely resembled that in hereditary spastic paraplegia (HSP). The importance of defective membrane trafficking in HSP and the association of NTE with the endoplasmic reticulum--the starting point for the constitutive secretory pathway and transport of neuronal materials into axons--prompted investigation for a role of NTE in secretion. Cultured NTE-deficient neurons displayed modestly impaired secretion, consistent with neuronal viability and damage in vivo initially restricted to distal parts of the longest axons.
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