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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] [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] [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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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] [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] [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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5
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Vandana VP, Darshini JK, Sankaran BP. Audiological Findings in Children with PLA2G6-Associated Neurodegeneration. J Am Acad Audiol 2022; 33:324-329. [PMID: 35705187 DOI: 10.1055/a-1877-2546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
BACKGROUND Audiological manifestations of patients with PLA2G6-associated neurodegeneration are limited. OBJECTIVE To analyze the audiological findings in a cohort of 13 children with infantile neuroaxonal dystrophy (INAD). METHOD Patients underwent a battery of audiological tests including tympanometry, distortion product otoacoustic emissions, impedance audiometry, and Brainstem Auditory Evoked Potentials (BAEPs). RESULTS Audiological studies of 13 children indicated sensorineural hearing loss in six children and auditory neuropathy spectrum disorder in four children. CONCLUSION This study may extend the auditory findings for INAD. Additional studies on quality of life and cognitive-brain degeneration related to this disease are required before making appropriate recommendations for aural rehabilitation.
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Affiliation(s)
| | - Jeevendra Kumar Darshini
- Department of Speech Pathology and Audiology, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Bindu Parayil Sankaran
- Department of Biochemical Genetics and Genetic Metabolic Disorders Service, The Children's Hospital at Westmead, Westmead, NSW, Australia
- The Children's Hospital at Westmead Clinical School, Faculty of Medicineand Health, University of Sydney, Sydney, NSW, Australia
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Rostampour D, Zolfaghari MR, Gholami M. Novel insertion mutation in the
PLA2G6
gene in an Iranian family with infantile neuroaxonal dystrophy. J Clin Lab Anal 2022; 36:e24253. [PMID: 35092705 PMCID: PMC8906051 DOI: 10.1002/jcla.24253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 01/01/2022] [Accepted: 01/11/2022] [Indexed: 11/12/2022] Open
Abstract
Background Infantile neuroaxonal dystrophy is an autosomal recessive neurological disorder. Individuals with infantile neuroaxonal dystrophy experience progressive loss of vision, mental skills and muscular control, and other variable clinical signs. Pathogenic variants in the PLA2G6 gene, encoding phospholipase A2, are recognized to be the fundamental reason for infantile neuroaxonal dystrophy. This study aimed to detect pathogenic variant in a consanguine Iranian family with infantile neuroaxonal dystrophy. Methods The mutation screening was done by whole exome sequencing followed by direct Sanger sequencing. Results We identified a homozygous insertion mutation, NM_003560: c.1548_1549insCG (p.G517Rfs*29) in exon 10 of PLA2G6 in the patient. The parents were heterozygous for variant. Conclusions Because of the clinical heterogeneity and rarity of infantile neuroaxonal dystrophy, whole exome sequencing is critical to confirm the diagnosis and is an excellent tool for INAD management.
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Affiliation(s)
- Dorsa Rostampour
- Department of Microbiology Qom Branch Islamic Azad University Qom Iran
| | | | - Milad Gholami
- Department of Biochemistry and Genetics School of Medicine Arak University of Medical Sciences Arak Iran
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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] [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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8
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Atwal PS, Midei M, Adams D, Fay A, Heerinckx F, Milner P. The infantile neuroaxonal dystrophy rating scale (INAD-RS). Orphanet J Rare Dis 2020; 15:195. [PMID: 32727524 PMCID: PMC7392694 DOI: 10.1186/s13023-020-01479-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 07/21/2020] [Indexed: 11/10/2022] Open
Abstract
Background INAD is an autosomal recessive neurogenetic disorder caused by biallelic pathogenic variants in PLA2G6. The downstream enzyme, iPLA2, plays a critical role in cell membrane homeostasis by helping to regulate levels of phospholipids. The clinical presentation occurs between 6 months and 3 years with global developmental regression, hypotonia, and progressive spastic tetraparesis. Progression is often rapid, resulting in severe spasticity, visual impairment, and cognitive decline, with many children not surviving past the first decade of life. To date, no accepted tool for assessing the severity of INAD exists; other commonly used scales (e.g. CHOP-INTEND, Modified Ashworth, Hammersmith Functional Motor Scale) do not accurately gauge the current severity of INAD, nor are they sensitive/specific enough to monitor disease progression. Finally, these other scales are not appropriate, because they do not address the combination of CNS, peripheral nerve, and visual pathology that occurs in children with INAD. Methods We have developed and validated a structured neurological examination for INAD (scored out of 80). The examination includes six main categories of pediatric developmental evaluation: 1) gross motor-and-truncal-stability skills, 2) fine motor skills, 3) bulbar function, 4) ocular function, 5) temporo-frontal function, and, 6) Functional evaluation of the autonomic nervous system. A cohort of patients diagnosed with INAD were followed prospectively to validate the score against disease severity and disease progression. Results We show significant correlation between the total neurological assessment score and months since symptom onset with a statistically significant (p = 6.7 × 10− 07) correlation between assessment score and disease onset. As hypothesized, the coefficient of months-since-symptom-onset is strongly negative, indicating a negative correlation between total score and months since symptom onset. Conclusion We have developed and validated a novel neurological assessment score in INAD that demonstrates strong correlation with disease severity and disease progression.
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Affiliation(s)
| | | | - Darius Adams
- Atlantic Medical Group, Morris Township, NJ, USA
| | - Alexander Fay
- University of California San Francisco (UCSF), San Francisco, CA, USA
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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] [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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10
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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] [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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11
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Wang B, Wu D, Tang J. Infantile neuroaxonal dystrophy caused by PLA2G6 gene mutation in a Chinese patient: A case report. Exp Ther Med 2018; 16:1290-1294. [PMID: 30112060 PMCID: PMC6090475 DOI: 10.3892/etm.2018.6347] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 05/02/2018] [Indexed: 12/31/2022] Open
Abstract
Infantile neuroaxonal dystrophy (INAD) is a rare neurodegenerative disorder. Phospholipase A2 group VI (PLA2G6) gene mutations have been identified in the majority of individuals with INAD. The present case report is on a Chinese female pediatric patient (age, 18 months) diagnosed with INAD with deafness. To date, only four cases of INAD with hearing loss have been reported, PLA2G6-association has not been investigated. Next-generation DNA sequencing technology was used to identify disease-associated genes and Sanger sequencing was applied to verify the mutation in the patient's pedigree. Two mutations were identified in the PLA2G6 gene: c.1T>C (E2) and c.497 (E4) to c.496 (E4): Insert C. The distribution frequency of those mutations in the Single Nucleotide Polymorphism, HapMap, 1000 Genomes and Exome Aggregation Consortium databases was 0. However, cases of INAD appear to be underreported, particularly those from China. The identification of two mutations in the present study suggests unique PLA2G6 mutations in Chinese patients, and greatly expands on the spectrum of known mutations in INAD patients.
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Affiliation(s)
- Baotian Wang
- Department of Pediatrics, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui 230022, P.R. China
| | - De Wu
- Department of Pediatrics, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui 230022, P.R. China
| | - Jiulai Tang
- Department of Pediatrics, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui 230022, P.R. China
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12
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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] [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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Abstract
Paediatric motor neuron diseases encompass a group of neurodegenerative diseases characterised by the onset of muscle weakness and atrophy before the age of 18 years, attributable to motor neuron loss across various neuronal networks in the brain and spinal cord. While the genetic underpinnings are diverse, advances in next generation sequencing have transformed diagnostic paradigms. This has reinforced the clinical phenotyping and molecular genetic expertise required to navigate the complexities of such diagnoses. In turn, improved genetic technology and subsequent gene identification have enabled further insights into the mechanisms of motor neuron degeneration and how these diseases form part of a neurodegenerative disorder spectrum. Common pathophysiologies include abnormalities in axonal architecture and function, RNA processing, and protein quality control. This review incorporates an overview of the clinical manifestations, genetics, and pathophysiology of inherited paediatric motor neuron disorders beyond classic SMN1-related spinal muscular atrophy and describes recent advances in next generation sequencing and its clinical application. Specific disease-modifying treatment is becoming a clinical reality in some disorders of the motor neuron highlighting the importance of a timely and specific diagnosis.
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14
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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] [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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15
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A new missense mutation in PLA2G6 gene among a family with infantile neuroaxonal dystrophy INAD. EGYPTIAN PEDIATRIC ASSOCIATION GAZETTE 2016. [DOI: 10.1016/j.epag.2016.11.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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16
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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] [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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17
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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] [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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18
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Kapoor S, Shah MH, Singh N, Rather MI, Bhat V, Gopinath S, Bindu PS, Taly AB, Sinha S, Nagappa M, Bharath RD, Mahadevan A, Narayanappa G, Chickabasaviah YT, Kumar A. Genetic Analysis of PLA2G6 in 22 Indian Families with Infantile Neuroaxonal Dystrophy, Atypical Late-Onset Neuroaxonal Dystrophy and Dystonia Parkinsonism Complex. PLoS One 2016; 11:e0155605. [PMID: 27196560 PMCID: PMC4873246 DOI: 10.1371/journal.pone.0155605] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 05/02/2016] [Indexed: 12/02/2022] Open
Abstract
Mutations in PLA2G6 were identified in patients with a spectrum of neurodegenerative conditions, such as infantile neuroaxonal dystrophy (INAD), atypical late-onset neuroaxonal dystrophy (ANAD) and dystonia parkinsonism complex (DPC). However, there is no report on the genetic analysis of families with members affected with INAD, ANAD and DPC from India. Therefore, the main aim of this study was to perform genetic analysis of 22 Indian families with INAD, ANAD and DPC. DNA sequence analysis of the entire coding region of PLA2G6 identified 13 different mutations, including five novel ones (p.Leu224Pro, p.Asp283Asn, p.Arg329Cys, p.Leu491Phe, and p.Arg649His), in 12/22 (54.55%) families with INAD and ANAD. Interestingly, one patient with INAD was homozygous for two different mutations, p.Leu491Phe and p.Ala516Val, and thus harboured four mutant alleles. With these mutations, the total number of mutations in this gene reaches 129. The absence of mutations in 10/22 (45.45%) families suggests that the mutations could be in deep intronic or promoter regions of this gene or these families could have mutations in a yet to be identified gene. The present study increases the mutation landscape of PLA2G6. The present finding will be useful for genetic diagnosis, carrier detection and genetic counselling to families included in this study and other families with similar disease condition.
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Affiliation(s)
- Saketh Kapoor
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, 560012, India
| | - Mohd Hussain Shah
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, 560012, India
| | - Nivedita Singh
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, 560012, India
| | - Mohammad Iqbal Rather
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, 560012, India
| | - Vishwanath Bhat
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, 560012, India
| | - Sindhura Gopinath
- Department of Biotechnology, R.V. College of Engineering, Bangalore, 560059, India
| | - Parayil Sankaran Bindu
- Department of Neurology, National Institute of Mental Health and Neuro Sciences, Bangalore, 560029, India
- * E-mail: (AK); (PSB)
| | - Arun B. Taly
- Department of Neurology, National Institute of Mental Health and Neuro Sciences, Bangalore, 560029, India
| | - Sanjib Sinha
- Department of Neurology, National Institute of Mental Health and Neuro Sciences, Bangalore, 560029, India
| | - Madhu Nagappa
- Department of Neurology, National Institute of Mental Health and Neuro Sciences, Bangalore, 560029, India
| | - Rose Dawn Bharath
- Department of Neuroimaging and Interventional Radiology, National Institute of Mental Health and Neuro Sciences, Bangalore, 560029, India
| | - Anita Mahadevan
- Department of Neuropathology, National Institute of Mental Health and Neuro Sciences, Bangalore, 560029, India
| | - Gayathri Narayanappa
- Department of Neuropathology, National Institute of Mental Health and Neuro Sciences, Bangalore, 560029, India
| | - Yasha T. Chickabasaviah
- Department of Neuropathology, National Institute of Mental Health and Neuro Sciences, Bangalore, 560029, India
| | - Arun Kumar
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, 560012, India
- * E-mail: (AK); (PSB)
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19
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Davids M, Kane MS, He M, Wolfe LA, Li X, Raihan MA, Chao KR, Bone WP, Boerkoel CF, Gahl WA, Toro C. Disruption of Golgi morphology and altered protein glycosylation in PLA2G6-associated neurodegeneration. J Med Genet 2015; 53:180-9. [PMID: 26668131 DOI: 10.1136/jmedgenet-2015-103338] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 11/09/2015] [Indexed: 01/07/2023]
Abstract
BACKGROUND Mutations in PLA2G6, which encodes the calcium-independent phospholipase A2 group VI, cause neurodegeneration and diffuse cortical Lewy body formation by a yet undefined mechanism. We assessed whether altered protein glycosylation due to abnormal Golgi morphology might be a factor in the pathology of this disease. METHODS Three patients presented with PLA2G6-associated neurodegeneration (PLAN); two had infantile neuroaxonal dystrophy (INAD) and one had adult-onset dystonia-parkinsonism. We analysed protein N-linked and O-linked glycosylation in cerebrospinal fluid, plasma, urine, and cultured skin fibroblasts using high performance liquid chromatography (HPLC) and matrix-assisted laser desorption ionization--time of flight/mass spectrometry (MALDI-TOF/MS). We also assessed sialylation and Golgi morphology in cultured fibroblasts by immunofluorescence and performed rescue experiments using a lentiviral vector. RESULTS The patients with INAD had PLA2G6 mutations NM_003560.2: c.[950G>T];[426-1077dup] and c.[1799G>A];[2221C>T] and the patient with dystonia-parkinsonism had PLA2G6 mutations NM_003560.2: c.[609G>A];[2222G>A]. All three patients had altered Golgi morphology and abnormalities of protein O-linked glycosylation and sialylation in cultured fibroblasts that were rescued by lentiviral overexpression of wild type PLA2G6. CONCLUSIONS Our findings add altered Golgi morphology, O-linked glycosylation and sialylation defects to the phenotypical spectrum of PLAN; these pathways are essential for correct processing and distribution of proteins. Lewy body and Tau pathology, two neuropathological features of PLAN, could emerge from these defects. Therefore, Golgi morphology, O-linked glycosylation and sialylation may play a role in the pathogenesis of PLAN and perhaps other neurodegenerative disorders.
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Affiliation(s)
- Mariska Davids
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NIH, Bethesda, Maryland, USA Office of the Clinical Director, NHGRI, National Institutes of Health, Bethesda, Maryland, USA
| | - Megan S Kane
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NIH, Bethesda, Maryland, USA Office of the Clinical Director, NHGRI, National Institutes of Health, Bethesda, Maryland, USA
| | - Miao He
- Department of Pathology and Laboratory of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA The Michael J Palmieri Metabolic Laboratory, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Lynne A Wolfe
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NIH, Bethesda, Maryland, USA Office of the Clinical Director, NHGRI, National Institutes of Health, Bethesda, Maryland, USA
| | - Xueli Li
- Department of Pathology and Laboratory of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA The Michael J Palmieri Metabolic Laboratory, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Mohd A Raihan
- Department of Pathology and Laboratory of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA The Michael J Palmieri Metabolic Laboratory, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Katherine R Chao
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NIH, Bethesda, Maryland, USA Office of the Clinical Director, NHGRI, National Institutes of Health, Bethesda, Maryland, USA
| | - William P Bone
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NIH, Bethesda, Maryland, USA Office of the Clinical Director, NHGRI, National Institutes of Health, Bethesda, Maryland, USA
| | - Cornelius F Boerkoel
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NIH, Bethesda, Maryland, USA Office of the Clinical Director, NHGRI, National Institutes of Health, Bethesda, Maryland, USA
| | - William A Gahl
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NIH, Bethesda, Maryland, USA Office of the Clinical Director, NHGRI, National Institutes of Health, Bethesda, Maryland, USA
| | - Camilo Toro
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NIH, Bethesda, Maryland, USA Office of the Clinical Director, NHGRI, National Institutes of Health, Bethesda, Maryland, USA
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20
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Novel PLA2G6 mutations associated with an exonic deletion due to non-allelic homologous recombination in a patient with infantile neuroaxonal dystrophy. Hum Genome Var 2015; 2:15048. [PMID: 27081553 PMCID: PMC4785535 DOI: 10.1038/hgv.2015.48] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Revised: 10/08/2015] [Accepted: 10/13/2015] [Indexed: 02/08/2023] Open
Abstract
Novel PLA2G6 mutations associated with p.Asp283Asn and a unique intragenic deletion of exons 4 and 5 due to non-allelic homologous recombination were identified in a Japanese female patient with typical infantile neuroaxonal dystrophy. The patient showed progressive tetraplegia beginning at 9 months. An electroencephalogram showed a diffuse increase in fast waves, and brain magnetic resonance imaging showed progressive brain atrophy and T2 hypointensity in the globus pallidus.
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21
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Ramanadham S, Ali T, Ashley JW, Bone RN, Hancock WD, Lei X. Calcium-independent phospholipases A2 and their roles in biological processes and diseases. J Lipid Res 2015; 56:1643-68. [PMID: 26023050 DOI: 10.1194/jlr.r058701] [Citation(s) in RCA: 135] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Indexed: 12/24/2022] Open
Abstract
Among the family of phospholipases A2 (PLA2s) are the Ca(2+)-independent PLA2s (iPLA2s) and they are designated group VI iPLA2s. In relation to secretory and cytosolic PLA2s, the iPLA2s are more recently described and details of their expression and roles in biological functions are rapidly emerging. The iPLA2s or patatin-like phospholipases (PNPLAs) are intracellular enzymes that do not require Ca(2+) for activity, and contain lipase (GXSXG) and nucleotide-binding (GXGXXG) consensus sequences. Though nine PNPLAs have been recognized, PNPLA8 (membrane-associated iPLA2γ) and PNPLA9 (cytosol-associated iPLA2β) are the most widely studied and understood. The iPLA2s manifest a variety of activities in addition to phospholipase, are ubiquitously expressed, and participate in a multitude of biological processes, including fat catabolism, cell differentiation, maintenance of mitochondrial integrity, phospholipid remodeling, cell proliferation, signal transduction, and cell death. As might be expected, increased or decreased expression of iPLA2s can have profound effects on the metabolic state, CNS function, cardiovascular performance, and cell survival; therefore, dysregulation of iPLA2s can be a critical factor in the development of many diseases. This review is aimed at providing a general framework of the current understanding of the iPLA2s and discussion of the potential mechanisms of action of the iPLA2s and related involved lipid mediators.
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Affiliation(s)
- Sasanka Ramanadham
- Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294 Comprehensive Diabetes Center, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Tomader Ali
- Undergraduate Research Office, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Jason W Ashley
- Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA 19104
| | - Robert N Bone
- Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294 Comprehensive Diabetes Center, University of Alabama at Birmingham, Birmingham, AL 35294
| | - William D Hancock
- Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294 Comprehensive Diabetes Center, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Xiaoyong Lei
- Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294 Comprehensive Diabetes Center, University of Alabama at Birmingham, Birmingham, AL 35294
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Fusco C, Frattini D, Panteghini C, Pascarella R, Garavaglia B. A case of infantile neuroaxonal dystrophy of neonatal onset. J Child Neurol 2015; 30:368-70. [PMID: 24870368 DOI: 10.1177/0883073814535493] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Infantile neuroaxonal dystrophy is a rare neurodegenerative disorder, with onset in the first or second year of life. Mutations in the PLA2G6 gene encoding iPLA2-VI, a calcium-independent phospholipase, have been identified in these children. In classic infantile neuroaxonal dystrophy-affected children, psychomotor regression is the most frequent presentation, usually with ataxia and optic atrophy, followed by the development of tetraparesis. We report a child carrying a homozygous mutation in the PLA2G6 gene with neonatal onset of disease and somewhat different clinical phenotype such as severe congenital hypotonia, marked weakness, and bulbar signs suggesting that infantile neuroaxonal dystrophy can start at birth with atypical phenotype.
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Affiliation(s)
- Carlo Fusco
- Pediatric Neurology Unit, Istituto di Ricovero e Cura a Carattere Scientifico, Arcispedale Santa Maria Nuova, Reggio Emilia, Italy
| | - Daniele Frattini
- Pediatric Neurology Unit, Istituto di Ricovero e Cura a Carattere Scientifico, Arcispedale Santa Maria Nuova, Reggio Emilia, Italy
| | - Celeste Panteghini
- Molecular Neurogenetics Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Rosario Pascarella
- Neurodiology Unit, Istituto di Ricovero e Cura a Carattere Scientifico, Arcispedale Santa Maria Nuova, Reggio Emilia, Italy
| | - Barbara Garavaglia
- Molecular Neurogenetics Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
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23
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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] [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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24
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Romani M, Kraoua I, Micalizzi A, Klaa H, Benrhouma H, Drissi C, Turki I, Castellana S, Mazza T, Valente EM, Gouider-Khouja N. Infantile and childhood onsetPLA2G6-associated neurodegeneration in a large North African cohort. Eur J Neurol 2014; 22:178-86. [DOI: 10.1111/ene.12552] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 07/11/2014] [Indexed: 11/30/2022]
Affiliation(s)
- M. Romani
- IRCCS Casa Sollievo della Sofferenza; Mendel Laboratory; San Giovanni Rotondo Italy
| | - I. Kraoua
- Research Unit 06/11 and Department of Child and Adolescent Neurology; National Institute Mongi Ben Hmida of Neurology; Tunis Tunisia
| | - A. Micalizzi
- IRCCS Casa Sollievo della Sofferenza; Mendel Laboratory; San Giovanni Rotondo Italy
- Department of Medical and Surgical Pediatric Sciences; University of Messina; Messina Italy
| | - H. Klaa
- Research Unit 06/11 and Department of Child and Adolescent Neurology; National Institute Mongi Ben Hmida of Neurology; Tunis Tunisia
| | - H. Benrhouma
- Research Unit 06/11 and Department of Child and Adolescent Neurology; National Institute Mongi Ben Hmida of Neurology; Tunis Tunisia
| | - C. Drissi
- Department of Neuroradiology; National Institute Mongi Ben Hmida of Neurology; Tunis Tunisia
| | - I. Turki
- Research Unit 06/11 and Department of Child and Adolescent Neurology; National Institute Mongi Ben Hmida of Neurology; Tunis Tunisia
| | - S. Castellana
- IRCCS Casa Sollievo della Sofferenza; Mendel Laboratory; San Giovanni Rotondo Italy
| | - T. Mazza
- IRCCS Casa Sollievo della Sofferenza; Mendel Laboratory; San Giovanni Rotondo Italy
| | - E. M. Valente
- IRCCS Casa Sollievo della Sofferenza; Mendel Laboratory; San Giovanni Rotondo Italy
- Section of Neurosciences; Department of Medicine and Surgery; University of Salerno; Salerno Italy
| | - N. Gouider-Khouja
- Research Unit 06/11 and Department of Child and Adolescent Neurology; National Institute Mongi Ben Hmida of Neurology; Tunis Tunisia
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25
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Cif L, Kurian MA, Gonzalez V, Garcia‐Ptacek S, Roujeau T, Gelisse P, Moura de Ribeiro AM, Crespel A, MacPherson L, Coubes P. Atypical PLA2G6-Associated Neurodegeneration: Social Communication Impairment, Dystonia and Response to Deep Brain Stimulation. Mov Disord Clin Pract 2014; 1:128-131. [PMID: 30363890 PMCID: PMC6183017 DOI: 10.1002/mdc3.12030] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Revised: 03/21/2014] [Accepted: 03/28/2014] [Indexed: 11/10/2022] Open
Affiliation(s)
- Laura Cif
- Département de NeurochirurgieCHRU MontpellierHôpital Gui de ChauliacMontpellierFrance
- INSERM, U661MontpellierFrance
- Université de Montpellier 1MontpellierFrance
- CNRS UMR5203Institut de Génomique FonctionnelleMontpellierFrance
- Département des Neurosciences CliniquesLaboratoire de Recherche en NeuroimagerieCentre Hospitalier Universitaire VaudoisUniversité de LausanneLausanneSwitzerland
| | - Manju A. Kurian
- Neurosciences UnitInstitute of Child Health, LondonUnited Kingdom
- Department of NeurologyGreat Ormond Street HospitalLondonUnited Kingdom
| | - Victoria Gonzalez
- Département de NeurochirurgieCHRU MontpellierHôpital Gui de ChauliacMontpellierFrance
- INSERM, U661MontpellierFrance
- Université de Montpellier 1MontpellierFrance
- CNRS UMR5203Institut de Génomique FonctionnelleMontpellierFrance
| | - Sara Garcia‐Ptacek
- Department of NeurobiologyCare Sciences and SocietyKarolinska InstitutetStockholmSweden
| | - Thomas Roujeau
- Département de NeurochirurgieCHRU MontpellierHôpital Gui de ChauliacMontpellierFrance
| | - Philippe Gelisse
- Epilepsy UnitUniversity Hospital of MontpellierMontpellierFrance
| | | | - Arielle Crespel
- Epilepsy UnitUniversity Hospital of MontpellierMontpellierFrance
| | - Lesley MacPherson
- Department of RadiologyBirmingham Children's HospitalBirminghamUnited Kingdom
| | - Philippe Coubes
- Département de NeurochirurgieCHRU MontpellierHôpital Gui de ChauliacMontpellierFrance
- INSERM, U661MontpellierFrance
- Université de Montpellier 1MontpellierFrance
- CNRS UMR5203Institut de Génomique FonctionnelleMontpellierFrance
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26
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Kohlschütter A, Eichler F. Childhood leukodystrophies: a clinical perspective. Expert Rev Neurother 2014; 11:1485-96. [DOI: 10.1586/ern.11.135] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Rupps R, Hukin J, Balicki M, Mercimek-Mahmutoglu S, Rolfs A, Dias C. Novel Mutations in FA2H-Associated Neurodegeneration: An Underrecognized Condition? J Child Neurol 2013; 28:1500-1504. [PMID: 22965561 DOI: 10.1177/0883073812458538] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Hereditary spastic paraplegias and related genetically heterogeneous disorders may be difficult to distinguish clinically. The FA2H gene has been associated with autosomal recessive neurodegenerative phenotypes encompassing spastic paraplegia with or without dystonia, and demyelinating leukodystrophy. To date, few individuals with mutations in the FA2H gene have been described. We report a 5-year-old girl of mixed Filipino and Vietnamese origin who presented with progressive lower limb spasticity and periventricular leukomalacia. The clinical diagnosis of FA2H-associated neurodegeneration was confirmed on the basis of 2 novel mutations in compound heterozygosity in the FA2H gene (p.S70L/p.P323L). This family highlights that FA2H-associated disorders may be underrecognized in children with neurodegeneration of many different ethnicities. Magnetic resonance imaging features play an important role as diagnostic clues in this and other hereditary spastic paraplegias. The consideration of this diagnosis is essential in providing families with important information on prognosis, as well as accurate genetic counseling.
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Affiliation(s)
- Rosemarie Rupps
- 1Department of Medical Genetics, University of British Columbia, Canada
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28
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Salih MA, Mundwiller E, Khan AO, AlDrees A, Elmalik SA, Hassan HH, Al-Owain M, Alkhalidi HMS, Katona I, Kabiraj MM, Chrast R, Kentab AY, Alzaidan H, Rodenburg RJ, Bosley TM, Weis J, Koenig M, Stevanin G, Azzedine H. New findings in a global approach to dissect the whole phenotype of PLA2G6 gene mutations. PLoS One 2013; 8:e76831. [PMID: 24130795 PMCID: PMC3792983 DOI: 10.1371/journal.pone.0076831] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2013] [Accepted: 08/29/2013] [Indexed: 01/12/2023] Open
Abstract
Mutations in PLA2G6 gene have variable phenotypic outcome including infantile neuroaxonal dystrophy, atypical neuroaxonal dystrophy, idiopathic neurodegeneration with brain iron accumulation and Karak syndrome. The cause of this phenotypic variation is so far unknown which impairs both genetic diagnosis and appropriate family counseling. We report detailed clinical, electrophysiological, neuroimaging, histologic, biochemical and genetic characterization of 11 patients, from 6 consanguineous families, who were followed for a period of up to 17 years. Cerebellar atrophy was constant and the earliest feature of the disease preceding brain iron accumulation, leading to the provisional diagnosis of a recessive progressive ataxia in these patients. Ultrastructural characterization of patients’ muscle biopsies revealed focal accumulation of granular and membranous material possibly resulting from defective membrane homeostasis caused by disrupted PLA2G6 function. Enzyme studies in one of these muscle biopsies provided evidence for a relatively low mitochondrial content, which is compatible with the structural mitochondrial alterations seen by electron microscopy. Genetic characterization of 11 patients led to the identification of six underlying PLA2G6 gene mutations, five of which are novel. Importantly, by combining clinical and genetic data we have observed that while the phenotype of neurodegeneration associated with PLA2G6 mutations is variable in this cohort of patients belonging to the same ethnic background, it is partially influenced by the genotype, considering the age at onset and the functional disability criteria. Molecular testing for PLA2G6 mutations is, therefore, indicated in childhood-onset ataxia syndromes, if neuroimaging shows cerebellar atrophy with or without evidence of iron accumulation.
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Affiliation(s)
- Mustafa A. Salih
- Division of Pediatric Neurology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Emeline Mundwiller
- Institut du Cerveau et de la Moelle épinière (ICM), Genotyping and Sequencing Facility, Groupe Hospitalier Pitié-Salpêtrière (GHPS), Paris, France
| | - Arif O. Khan
- Division of Paediatrics Ophthalmology, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia
| | - Abdulmajeed AlDrees
- Department of Physiology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Salah A. Elmalik
- Department of Physiology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Hamdy H. Hassan
- Department of Radiology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Mohammed Al-Owain
- Department of Medical Genetics, King Faisal specialist Hospital & Research Centre, Riyadh, Saudi Arabia
| | - Hisham M. S. Alkhalidi
- Department of Pathology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Istvan Katona
- Institut für Neuropathologie, Universitätsklinikum der RWTH, Aachen, Germany
| | | | - Roman Chrast
- Department of Medical Genetics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Amal Y. Kentab
- Division of Pediatric Neurology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Hamad Alzaidan
- Department of Medical Genetics, King Faisal specialist Hospital & Research Centre, Riyadh, Saudi Arabia
| | - Richard J. Rodenburg
- Radboud University Medical Center, Nijmegen Center for Mitochondrial Disorders, Department of Pediatrics, Department of Laboratory Medicine, 774 Laboratory for Genetic, Endocrine and Metabolic disorders (LGEM), Nijmegen, The Netherlands
| | - Thomas M. Bosley
- Department of Ophthalmology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
- Neurology Division, Cooper University Hospital, Camden, New Jersey, USA
| | - Joachim Weis
- Institut für Neuropathologie, Universitätsklinikum der RWTH, Aachen, Germany
| | - Michel Koenig
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Centre National de la Recherche Scientifique (CNRS)/Institut National de la Santé et de la Recherche Médicale (INSERM)/Université de Strasbourg, et Collège de France, Illkirch, France
| | - Giovanni Stevanin
- Institut du Cerveau et de la Moelle épinière (ICM), Genotyping and Sequencing Facility, Groupe Hospitalier Pitié-Salpêtrière (GHPS), Paris, France
- École Pratique des Hautes Etudes (EPHE), Paris, France
- INSERM-U975, Paris, France
- CNRS-UMR (Unité mixte de Recherche) 7225, Paris, France
- Université Pierre et Marie Curie – Paris 6, (UMR-S)_975, Centre de Recherche de l’Institut du Cerveau et de la Moelle épinière (cricm), Groupe Hospitalier Pitié-Salpêtrière (GHPS), Paris, France
- Assistance Publique des Hôpitaux de Paris (APHP), département de Génétique et Cytogénétique, GHPS, Paris, France
| | - Hamid Azzedine
- Department of Medical Genetics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
- * E-mail:
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29
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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. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2013; 110:49-71. [PMID: 24209433 PMCID: PMC6059649 DOI: 10.1016/b978-0-12-410502-7.00003-x] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [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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30
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Morrison K, Witte K, Mayers JR, Schuh AL, Audhya A. Roles of acidic phospholipids and nucleotides in regulating membrane binding and activity of a calcium-independent phospholipase A2 isoform. J Biol Chem 2012; 287:38824-34. [PMID: 23007400 DOI: 10.1074/jbc.m112.391508] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Phospholipase A(2) activity plays key roles in generating lipid second messengers and regulates membrane topology through the generation of asymmetric lysophospholipids. In particular, the Group VIA phospholipase A(2) (GVIA-iPLA(2)) subfamily of enzymes functions independently of calcium within the cytoplasm of cells and has been implicated in numerous cellular processes, including proliferation, apoptosis, and membrane transport steps. However, mechanisms underlying the spatial and temporal regulation of these enzymes have remained mostly unexplored. Here, we examine the subset of Caenorhabditis elegans lipases that harbor a consensus motif common to members of the GVIA-iPLA(2) subfamily. Based on sequence homology, we identify IPLA-1 as the closest C. elegans homolog of human GVIA-iPLA(2) enzymes and use a combination of liposome interaction studies to demonstrate a role for acidic phospholipids in regulating GVIA-iPLA(2) function. Our studies indicate that IPLA-1 binds directly to multiple acidic phospholipids, including phosphatidylserine, phosphatidylglycerol, cardiolipin, phosphatidic acid, and phosphorylated derivatives of phosphatidylinositol. Moreover, the presence of these acidic lipids dramatically elevates the specific activity of IPLA-1 in vitro. We also found that the addition of ATP and ADP promote oligomerization of IPLA-1, which probably underlies the stimulatory effect of nucleotides on its activity. We propose that membrane composition and the presence of nucleotides play key roles in recruiting and modulating GVIA-iPLA(2) activity in cells.
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Affiliation(s)
- Kylee Morrison
- Department of Biomolecular Chemistry, University of Wisconsin-Madison Medical School, Madison, Wisconsin 53706, USA
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31
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Carpenter S, Soares H, Brandão O, Souto Moura C, Castro L, Rodrigues E, Cunha AL, Bartosch C. A novel type of familial proximal axonal dystrophy: three cases and a review of the axonal dystrophies. Eur J Paediatr Neurol 2012; 16:292-300. [PMID: 21925911 DOI: 10.1016/j.ejpn.2011.08.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Revised: 08/24/2011] [Accepted: 08/28/2011] [Indexed: 01/09/2023]
Abstract
Three related infants of Roma ancestry, two of them siblings, showed hypotonia, predominantly axial, from birth, difficulty swallowing, myoclonic seizures, and respiratory difficulty. Dysmorphic features, principally micrognathia were present. EEGs showed focal epileptiform abnormalities. All three died in their 5th month from respiratory insufficiency complicated by pneumonia. Autopsy showed small brains without malformation. Microscopy revealed numerous axonal spheroids involving particularly the brain stem and spinal cord, with especial prominence in the middle cerebellar peduncle, the anterior part of the thalamic reticular nuclei, and the anterior horns and columns of the spinal cord. Spheroids that appeared to be on axons of lower motor neurons were especially large. No spheroids were seen in peripheral nerves; electron microscopy did not show spheroids in skin. By electron microscopy spheroids contained neurofilaments, sparse mitochondria, and electron dense granules. The material did not allow identification of microtubules. Closely packed vesicles excluded neurofilamanets from the center of many spheroids, especially in the middle cerebellar peduncle. Sprouting of axons from the surface of many spheroids was seen. This disease is distinct from the well described type of infantile neuroaxonal dystrophy (Seitelberger's disease) in view of the distribution of spheroids, presence of spheroids on proximal rather than distal parts of axons, sparing of the peripheral nerves, lack of staining for synuclein, presence of sprouting, and lack of membranous profiles in the spheroids. A review of reported types of axonal dystrophy has not shown identical cases.
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Affiliation(s)
- Stirling Carpenter
- Department of Anatomic Pathology, Hospital São Joâo, Alameda Professor Hernani Monteiro, Porto 4200, Portugal.
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32
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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] [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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33
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Aleman M, Finno CJ, Higgins RJ, Puschner B, Gericota B, Gohil K, LeCouteur RA, Madigan JE. Evaluation of epidemiological, clinical, and pathological features of neuroaxonal dystrophy in Quarter Horses. J Am Vet Med Assoc 2011; 239:823-33. [DOI: 10.2460/javma.239.6.823] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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34
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Kurian MA, McNeill A, Lin JP, Maher ER. Childhood disorders of neurodegeneration with brain iron accumulation (NBIA). Dev Med Child Neurol 2011; 53:394-404. [PMID: 21480873 DOI: 10.1111/j.1469-8749.2011.03955.x] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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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35
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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] [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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Fyfe JC, Al-Tamimi RA, Castellani RJ, Rosenstein D, Goldowitz D, Henthorn PS. Inherited neuroaxonal dystrophy in dogs causing lethal, fetal-onset motor system dysfunction and cerebellar hypoplasia. J Comp Neurol 2010; 518:3771-84. [PMID: 20653033 DOI: 10.1002/cne.22423] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Neuroaxonal dystrophy in brainstem, spinal cord tracts, and spinal nerves accompanied by cerebellar hypoplasia was observed in a colony of laboratory dogs. Fetal akinesia was documented by ultrasonographic examination. At birth, affected puppies exhibited stereotypical positioning of limbs, scoliosis, arthrogryposis, pulmonary hypoplasia, and respiratory failure. Regional hypoplasia in the central nervous system was apparent grossly, most strikingly as underdeveloped cerebellum and spinal cord. Histopathologic abnormalities included swollen axons and spheroids in brainstem and spinal cord tracts; reduced cerebellar foliation, patchy loss of Purkinje cells, multifocal thinning of the external granular cell layer, and loss of neurons in the deep cerebellar nuclei; spheroids and loss of myelinated axons in spinal roots and peripheral nerves; increased myocyte apoptosis in skeletal muscle; and fibrofatty connective tissue proliferation around joints. Breeding studies demonstrated that the canine disorder is a fully penetrant, simple autosomal recessive trait. The disorder demonstrated a type and distribution of lesions homologous to that of human infantile neuroaxonal dystrophy (INAD), most commonly caused by mutations of phospholipase A2 group VI gene (PLA2G6), but alleles of informative markers flanking the canine PLA2G6 locus did not associate with the canine disorder. Thus, fetal-onset neuroaxonal dystrophy in dogs, a species with well-developed genome mapping resources, provides a unique opportunity for additional disease gene discovery and understanding of this pathology.
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Affiliation(s)
- John C Fyfe
- Laboratory of Comparative Medical Genetics, Department of Microbiology & Molecular Genetics, Michigan State University, East Lansing, Michigan 48824, USA.
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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] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Kohlschütter A, Bley A, Brockmann K, Gärtner J, Krägeloh-Mann I, Rolfs A, Schöls L. Leukodystrophies and other genetic metabolic leukoencephalopathies in children and adults. Brain Dev 2010; 32:82-9. [PMID: 19427149 DOI: 10.1016/j.braindev.2009.03.014] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2008] [Revised: 03/21/2009] [Accepted: 03/22/2009] [Indexed: 11/17/2022]
Abstract
Abnormalities of CNS white matter are frequently detected in patients with neurological disorders when MRI studies are performed. Among the many causes of such abnormalities, a large group of rare genetic diseases poses considerable diagnostic problems. Here we present a compilation of genetic leukoencephalopathies to consider when one is confronted with white matter disease of possibly genetic origin. The table contains essentials such as age at onset of symptoms, clinical and MRI characteristics, basic defect, and useful diagnostic studies. The table serves as a diagnostic check list.
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Brosnahan M, Holbrook T, Ritchey J. Neuroaxonal Dystrophy Associated with Cerebellar Dysfunction in a 5-Month-Old Pony of the Americas Colt. J Vet Intern Med 2009; 23:1303-6. [DOI: 10.1111/j.1939-1676.2009.0379.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Wu Y, Jiang Y, Gao Z, Wang J, Yuan Y, Xiong H, Chang X, Bao X, Zhang Y, Xiao J, Wu X. Clinical study and PLA2G6 mutation screening analysis in Chinese patients with infantile neuroaxonal dystrophy. Eur J Neurol 2008; 16:240-5. [PMID: 19138334 DOI: 10.1111/j.1468-1331.2008.02397.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND AND PURPOSE Infantile neuroaxonal dystrophy (INAD) is a rare autosomal recessive neurodegenerative disorder. The most typical neuropathological finding of this disease is axonal swelling. Before the identification of associated mutations in PLA2G6-encoding iPLA(2)-VIA (cytosolic Ca(2+)-independent phospholipids A(2), group VIA) in 2006, neuropathological evidence was critical for definitive diagnosis. Only five genetic studies in INAD patients have been published worldwide, wherein 44 mutations were reported. To define the clinical and genetic characteristics of Chinese patients with INAD, 10 cases were analyzed. METHODS For 10 cases of INAD, extensive clinical investigations, neuropathological examination, and mutation screening in PLA2G6 were performed. RESULTS All cases displayed typical clinical features. Axonal swelling was found in skin or sural nerve biopsy specimens in three cases. Twelve PLA2G6 mutations were identified, nine of which were novel. These novel mutations include six missense, one abolishing the normal start codon, one nonsense, and one splice-site mutation. CONCLUSIONS The nine novel mutations identified in this study suggest the uniqueness of the PLA2G6 mutation spectrum in Chinese patients, and greatly extends the spectrum of known mutations in INAD patients. In addition to pathological evidence, genetic analysis can inform definitive diagnosis of INAD.
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Affiliation(s)
- Y Wu
- Department of Pediatrics, Peking University, First Hospital, Beijing, China
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