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Dreha-Kulaczewski S, Sahoo P, Preusse M, Gkalimani I, Dechent P, Helms G, Hofer S, Steinfeld R, Gärtner J. Folate receptor α deficiency - Myelin-sensitive MRI as a reliable biomarker to monitor the efficacy and long-term outcome of a new therapeutic approach. J Inherit Metab Dis 2024; 47:387-403. [PMID: 38200656 DOI: 10.1002/jimd.12713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 11/23/2023] [Accepted: 12/27/2023] [Indexed: 01/12/2024]
Abstract
Cerebral folate transport deficiency, caused by a genetic defect in folate receptor α, is a devastating neurometabolic disorder that, if untreated, leads to epileptic encephalopathy, psychomotor decline and hypomyelination. Currently, there are limited data on effective dosage and duration of treatment, though early diagnosis and therapy with folinic acid appears critical. The aim of this long-term study was to identify new therapeutic approaches and novel biomarkers for assessing efficacy, focusing on myelin-sensitive MRI. Clinical, biochemical, structural and quantitative MRI parameters of seven patients with genetically confirmed folate receptor α deficiency were acquired over 13 years. Multimodal MRI approaches comprised MR-spectroscopy (MRS), magnetization transfer (MTI) and diffusion tensor imaging (DTI) sequences. Patients started oral treatment immediately following diagnosis or in an interval of up to 2.5 years. Escalation to intravenous and intrathecal administration was performed in the absence of effects. Five patients improved, one with a presymptomatic start of therapy remained symptom-free, and one with inconsistent treatment deteriorated. While CSF 5-methyltetrahydrofolate and MRS parameters normalized immediately after therapy initiation, myelin-sensitive MTI and DTI measures correlated with gradual clinical improvement and ongoing myelination under therapy. Early initiation of treatment at sufficient doses, considering early intrathecal applications, is critical for favorable outcome. The majority of patients showed clinical improvements that correlated best with MTI parameters, allowing individualized monitoring of myelination recovery. Presymptomatic therapy seems to ensure normal development and warrants newborn screening. Furthermore, the quantitative parameters of myelin-sensitive MRI for therapy assessments can now be used for hypomyelination disorders in general.
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Affiliation(s)
- Steffi Dreha-Kulaczewski
- Division of Pediatric Neurology, Department of Pediatrics and Adolescent Medicine, University Medical Center Göttingen, Göttingen, Germany
| | - Prativa Sahoo
- Division of Pediatric Neurology, Department of Pediatrics and Adolescent Medicine, University Medical Center Göttingen, Göttingen, Germany
| | - Matthias Preusse
- Kinderkrankenhaus Amsterdamer Strasse, Klinik für Kinder- und Jugendmedizin, Köln, Germany
| | - Irini Gkalimani
- Division of Pediatric Neurology, Department of Pediatrics and Adolescent Medicine, University Medical Center Göttingen, Göttingen, Germany
| | - Peter Dechent
- MR-Research in Neuroscience, Department of Cognitive Neurology, University Medical Center Göttingen, Göttingen, Germany
| | - Gunther Helms
- Medical Radiation Physics, Lund University, Lund, Sweden
| | - Sabine Hofer
- Department of Neurology, University Medical Center Göttingen, Göttingen, Germany
| | - Robert Steinfeld
- Division of Pediatric Neurology, Department of Pediatrics and Adolescent Medicine, University Medical Center Göttingen, Göttingen, Germany
| | - Jutta Gärtner
- Division of Pediatric Neurology, Department of Pediatrics and Adolescent Medicine, University Medical Center Göttingen, Göttingen, Germany
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Potic A, Perrier S, Radovic T, Gavrilovic S, Ostojic J, Tran LT, Thiffault I, Pastinen T, Schiffmann R, Bernard G. Hypomyelination caused by a novel homozygous pathogenic variant in FOLR1: complete clinical and radiological recovery with oral folinic acid therapy and review of the literature. Orphanet J Rare Dis 2023; 18:187. [PMID: 37443037 DOI: 10.1186/s13023-023-02802-6] [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: 01/19/2023] [Accepted: 07/05/2023] [Indexed: 07/15/2023] Open
Abstract
BACKGROUND Neurodegeneration due to cerebral folate transport deficiency is a rare autosomal recessive disorder caused by biallelic pathogenic variants in FOLR1. Onset typically occurs in late infancy and is characterized by psychomotor regression, epilepsy, and a hypomyelinating leukodystrophy on magnetic resonance imaging. If left untreated, progressive neurodegeneration occurs. However, early treatment with folinic acid has been shown to stabilize or reverse neurological features. Approximately thirty patients have been described worldwide. Here, we report the first two cases with genetically proven cerebral folate transport deficiency from South-Eastern Europe, describe the effect of oral folinic acid therapy on clinical and neuroradiological features and review the literature. RESULTS Two siblings presented in childhood with clinical and radiological findings consistent with a hypomyelinating leukodystrophy. Exome sequencing revealed a novel homozygous pathogenic variant in FOLR1 (c.465_466delinsTG; p.W156G), confirming the diagnosis of neurodegeneration due to cerebral folate transport deficiency. Folinic acid treatment was promptly initiated in both patients. The younger sibling was treated early in disease course at 2 years of age, and demonstrated complete recovery in clinical and MRI features. The older sibling, who was 8 years of age at the time of diagnosis and treatment, demonstrated partial but substantial improvements. CONCLUSION We present the first account in the literature that early treatment initiation with oral folinic acid alone can result in complete neurological recovery of both clinical and radiological abnormalities in neurodegeneration due to cerebral folate deficiency. Moreover, through the report of these patients along with review of the literature, we provide information about the natural history of the disease with comparison of treatment effects at different stages of disease progression. This report also reinforces the importance of universal access to genetic testing to ensure prompt diagnoses for treatable disorders.
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Affiliation(s)
- Ana Potic
- Clinic for Child Neurology and Psychiatry, Department of Neurology, University of Belgrade, 6A Dr. Subotica Street, 11000, Belgrade, Serbia.
| | - Stefanie Perrier
- Departments of Neurology and Neurosurgery, McGill University, Montreal, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montreal, Canada
| | - Tijana Radovic
- University Children's Hospital, Department of Radiology, University of Belgrade, Belgrade, Serbia
| | - Svetlana Gavrilovic
- University Clinical Centre of Serbia, Centre for Radiology and Magnetic Resonance, University of Belgrade, Belgrade, Serbia
| | - Jelena Ostojic
- Faculty of Medicine, Department of Radiology, University of Novi Sad, Novi Sad, Serbia
| | - Luan T Tran
- Departments of Neurology and Neurosurgery, McGill University, Montreal, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montreal, Canada
| | - Isabelle Thiffault
- Genomic Medicine Center, Children's Mercy Hospital, Kansas City, MO, USA
- University of Missouri Kansas City School of Medicine, Kansas City, MO, USA
- Department of Pathology and Laboratory Medicine, Children's Mercy Hospital, Kansas City, MO, USA
| | - Tomi Pastinen
- Genomic Medicine Center, Children's Mercy Hospital, Kansas City, MO, USA
- University of Missouri Kansas City School of Medicine, Kansas City, MO, USA
| | | | - Geneviève Bernard
- Departments of Neurology and Neurosurgery, McGill University, Montreal, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montreal, Canada
- Departments of Pediatrics and Human Genetics, McGill University, Montreal, Canada
- Department Specialized Medicine, Division of Medical Genetics, McGill University Health Centre, Montreal, Canada
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Cerebral folate transporter deficiency: a potentially treatable neurometabolic disorder. Acta Neurol Belg 2023; 123:121-127. [PMID: 34002331 DOI: 10.1007/s13760-021-01700-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 04/30/2021] [Indexed: 10/21/2022]
Abstract
Cerebral folate deficiency (CFD) syndrome is a rare treatable neurometabolic disorder with low levels of the active form of folaten in cerebrospinal fluid (CSF) arising from different causes such as FOLR1 gene mutations or autoantibodies against the folate receptor-alpha (FR) protein that can block folate transport across the choroid plexus. It is characterized by late infantile onset refractory seizures, ataxia, movement disorder, and unexplained global developmental delay. Here, we report a patient diagnosed with autistic spectrum disorder, followed by refractory myoclonic-atonic seizures, ataxia, and loss of motor skills over time. A homozygous missense (c.665A > G) mutation in FOLR1 gene and extremely low CSF 5-methyltetrahydrofolate level led to the diagnosis of CFD. Although she was initiated on combined oral and intravenous high doses of folinic acid treatment at 6 years of age, mild improvement was achieved in terms of epileptic seizures and motor skills. It is important that CFD should be kept in mind in cases with refractory myoclonic-atonic seizure and folinic acid treatment should be started as soon as possible.
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Folate Receptor Alpha Autoantibodies in Autism Spectrum Disorders: Diagnosis, Treatment and Prevention. J Pers Med 2021; 11:jpm11080710. [PMID: 34442354 PMCID: PMC8398778 DOI: 10.3390/jpm11080710] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Revised: 07/20/2021] [Accepted: 07/21/2021] [Indexed: 11/16/2022] Open
Abstract
Folate deficiency and folate receptor autoimmune disorder are major contributors to infertility, pregnancy related complications and abnormal fetal development including structural and functional abnormalities of the brain. Food fortification and prenatal folic acid supplementation has reduced the incidence of neural tube defect (NTD) pregnancies but is unlikely to prevent pregnancy-related complications in the presence of folate receptor autoantibodies (FRAb). In pregnancy, these autoantibodies can block folate transport to the fetus and in young children, folate transport to the brain. These antibodies are prevalent in neural tube defect pregnancies and in developmental disorders such as cerebral folate deficiency (CFD) syndrome and autism spectrum disorder (ASD). In the latter conditions, folinic acid treatment has shown clinical improvement in some of the core ASD deficits. Early testing for folate receptor autoantibodies and intervention is likely to result in a positive outcome. This review discusses the first identification of FRAb in women with a history of neural tube defect pregnancy and FRAb’s association with sub-fertility and preterm birth. Autoantibodies against folate receptor alpha (FRα) are present in about 70% of the children with a diagnosis of ASD, and a significant number of these children respond to oral folinic acid with overall improvements in speech, language and social interaction. The diagnosis of folate receptor autoimmune disorder by measuring autoantibodies against FRα in the serum provides a marker with the potential for treatment and perhaps preventing the pathologic consequences of folate receptor autoimmune disorder.
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Brunetti S, Malerba L, Giordano L, Parrini E, Guerrini R, Palumbo G, Parazzini C, Bestetti I, Accorsi P. Cerebral folate transporter deficiency syndrome in three siblings: Why genetic testing for developmental and epileptic encephalopathies should be performed early and include the FOLR1 gene. Am J Med Genet A 2021; 185:2526-2531. [PMID: 34008900 DOI: 10.1002/ajmg.a.62345] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 04/05/2021] [Accepted: 04/16/2021] [Indexed: 11/08/2022]
Abstract
Cerebral folate transporter deficiency syndrome, caused by FOLR-1 mutations is characterized by late infantile onset, severe developmental regression, epilepsy, and leukodystrophy. An extremely low concentration of 5-methyltetrahydrofolate in the cerebrospinal fluid provides a crucial clue to its diagnosis and is a treatment target. Oral or intravenous folinic acid (5-formyltetrahydrofolate) administration improves clinical symptoms and brain magnetic resonance imaging (MRI) findings. We describe three siblings carrying a novel homozygous FOLR1 nonsense mutation, that were referred due to intractable epilepsy and progressive neurological decline. Brain MRI showed hypomyelination and cerebellar atrophy. Folinic acid (oral and intravenous) supplementation, initiated after over 15 years illness, has failed to result in any sizeable clinical or neurophysiological improvement. Cerebral folate transport deficiency bears overlapping clinical features with many severe developmental encephalopathies. It is crucial to recognize FOLR1 signs and establish an early clinical and molecular diagnosis in order to provide timely folinic acid treatment and improve outcome.
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Affiliation(s)
- Sara Brunetti
- Child and Adolescent Neurology and Psychiatry Unit, Children Hospital, ASST Spedali Civili of Brescia, Brescia, Italy
| | - Laura Malerba
- Child and Adolescent Neurology and Psychiatry Unit, Children Hospital, ASST Spedali Civili of Brescia, Brescia, Italy
| | - Lucio Giordano
- Child and Adolescent Neurology and Psychiatry Unit, Children Hospital, ASST Spedali Civili of Brescia, Brescia, Italy
| | - Elena Parrini
- Pediatric Neurology, Neurogenetics and Neurobiology Unit and Laboratories, Neuroscience Centre, A. Meyer Children's Hospital, University of Florence, Florence, Italy
| | - Renzo Guerrini
- Pediatric Neurology, Neurogenetics and Neurobiology Unit and Laboratories, Neuroscience Centre, A. Meyer Children's Hospital, University of Florence, Florence, Italy
| | - Giovanni Palumbo
- Neuroradiology Department, University of Brescia, Brescia, Italy
| | - Cecilia Parazzini
- Pediatric radiology and neuroradiology Department, Children's Hospital V. Buzzi, Milan, Italy
| | - Ilaria Bestetti
- Research Laboratory of Medical Cytogenetics and Molecular Genetics, IRCCS Istituto Auxologico Italiano, Milan, Italy.,Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| | - Patrizia Accorsi
- Child and Adolescent Neurology and Psychiatry Unit, Children Hospital, ASST Spedali Civili of Brescia, Brescia, Italy
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Zhang C, Deng X, Wen Y, He F, Yin F, Peng J. First case report of cerebral folate deficiency caused by a novel mutation of FOLR1 gene in a Chinese patient. BMC MEDICAL GENETICS 2020; 21:235. [PMID: 33243190 PMCID: PMC7691102 DOI: 10.1186/s12881-020-01162-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 11/03/2020] [Indexed: 11/25/2022]
Abstract
Background Cerebral folate deficiency (CFD) is a neurological disease, hallmarked by remarkable low concentrations of 5-methyltetrahydrofolic acid (5-MTHF) in cerebrospinal fluid (CSF). The primary causes of CFD include the presence of folate receptor (FR) autoantibodies, defects of FR encoding gene FOLR1, mitochondrial diseases and congenital abnormalities in folate metabolism. Case presentation Here we first present a Chinese male CFD patient whose seizure onset at 2 years old with convulsive status epilepticus. Magnetic Resonance Imaging (MRI) revealed the development of encephalomalacia, laminar necrosis in multiple lobes of the brain and cerebellar atrophy. Whole Exome Sequencing (WES) uncovered a homozygous missense variant of c.524G > T (p.C175F) in FOLR1 gene. Further laboratory tests demonstrated the extremely low level of 5-MTHF in the CSF from this patient, which was attributed to cerebral folate transport deficiency. Following the intravenous and oral treatment of calcium folinate, the concentrations of 5-MTHF in CSF were recovered to the normal range and seizure symptoms were relieved as well. Conclusions One novel variation of FOLR1 was firstly identified from a Chinese male patient with tonic-clonic seizures, developmental delay, and ataxia. The WES and laboratory results elucidated the etiology of the symptoms. Clinical outcomes were improved by early diagnosis and proper treatment.
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Affiliation(s)
- Ciliu Zhang
- Xiangya Hospital Central South University, 87 Xiangya Road, Changsha, Hunan, 410008, P.R. China
| | - Xiaolu Deng
- Xiangya Hospital Central South University, 87 Xiangya Road, Changsha, Hunan, 410008, P.R. China
| | - Yafei Wen
- XiangYa School of Medicine of Central South University, 172 Tongzipo Road, Changsha, Hunan, 410013, P.R. China
| | - Fang He
- Xiangya Hospital Central South University, 87 Xiangya Road, Changsha, Hunan, 410008, P.R. China
| | - Fei Yin
- Xiangya Hospital Central South University, 87 Xiangya Road, Changsha, Hunan, 410008, P.R. China
| | - Jing Peng
- Xiangya Hospital Central South University, 87 Xiangya Road, Changsha, Hunan, 410008, P.R. China.
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Pharmacoresistant Epilepsy in Childhood: Think of the Cerebral Folate Deficiency, a Treatable Disease. Brain Sci 2020; 10:brainsci10110762. [PMID: 33105619 PMCID: PMC7690394 DOI: 10.3390/brainsci10110762] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 10/16/2020] [Accepted: 10/19/2020] [Indexed: 12/11/2022] Open
Abstract
Cerebral folate deficiency (CFD) is a neurological disorder characterized by low levels of 5-methyltetrahydrofolate (5-MTHF) in the cerebrospinal fluid (CSF). The prevalence of this autosomal recessive disorder is estimated to be <1/1,000,000. Fifteen different pathogenic variants in the folate receptor 1 gene (FOLR1) encoding the receptor of folate α (FRα) have already been described. We present a new pathogenic variation in the FOLR1 in a childhood-stage patient. We aim to establish the core structure of the FRα protein mandatory for its activity. A three-year-old child was admitted at hospital for a first febrile convulsions episode. Recurrent seizures without fever also occurred a few months later, associated with motor and cognitive impairment. Various antiepileptic drugs failed to control seizures. Magnetic resonance imaging (MRI) showed central hypomyelination and biological analysis revealed markedly low levels of 5-MTHF in CSF. Next generation sequencing (NGS) confirmed a CFD with a FOLR1 homozygous variation (c.197 G > A, p.Cys66Tyr). This variation induces an altered folate receptor α protein and underlines the role of a disulfide bond: Cys66-Cys109, essential to transport 5-MTHF into the central nervous system. Fortunately, this severe form of CFD had remarkably responded to high doses of oral folinic acid combined with intravenous administrations.
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Papandreou A, Danti FR, Spaull R, Leuzzi V, Mctague A, Kurian MA. The expanding spectrum of movement disorders in genetic epilepsies. Dev Med Child Neurol 2020; 62:178-191. [PMID: 31784983 DOI: 10.1111/dmcn.14407] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/01/2019] [Indexed: 12/27/2022]
Abstract
An ever-increasing number of neurogenetic conditions presenting with both epilepsy and atypical movements are now recognized. These disorders within the 'genetic epilepsy-dyskinesia' spectrum are clinically and genetically heterogeneous. Increased clinical awareness is therefore necessary for a rational diagnostic approach. Furthermore, careful interpretation of genetic results is key to establishing the correct diagnosis and initiating disease-specific management strategies in a timely fashion. In this review we describe the spectrum of movement disorders associated with genetically determined epilepsies. We also propose diagnostic strategies and putative pathogenic mechanisms causing these complex syndromes associated with both seizures and atypical motor control. WHAT THIS PAPER ADDS: Implicated genes encode proteins with very diverse functions. Pathophysiological mechanisms by which epilepsy and movement disorder phenotypes manifest are often not clear. Early diagnosis of treatable disorders is essential and next generation sequencing may be required.
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Affiliation(s)
- Apostolos Papandreou
- Molecular Neurosciences, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, London, UK
- Department of Neurology, Great Ormond Street Hospital, London, UK
| | - Federica Rachele Danti
- Molecular Neurosciences, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, London, UK
- Department of Human Neuroscience, Unit of Child Neurology and Psychiatry, Sapienza University of Rome, Rome, Italy
| | - Robert Spaull
- Department of Paediatric Neurology, Bristol Royal Hospital for Children, Bristol, UK
- Bristol Medical School, University of Bristol, Bristol, UK
| | - Vincenzo Leuzzi
- Department of Human Neuroscience, Unit of Child Neurology and Psychiatry, Sapienza University of Rome, Rome, Italy
| | - Amy Mctague
- Molecular Neurosciences, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, London, UK
- Department of Neurology, Great Ormond Street Hospital, London, UK
| | - Manju A Kurian
- Molecular Neurosciences, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, London, UK
- Department of Neurology, Great Ormond Street Hospital, London, UK
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Pope S, Artuch R, Heales S, Rahman S. Cerebral folate deficiency: Analytical tests and differential diagnosis. J Inherit Metab Dis 2019; 42:655-672. [PMID: 30916789 DOI: 10.1002/jimd.12092] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 03/19/2019] [Accepted: 03/25/2019] [Indexed: 11/07/2022]
Abstract
Cerebral folate deficiency is typically defined as a deficiency of the major folate species 5-methyltetrahydrofolate in the cerebrospinal fluid (CSF) in the presence of normal peripheral total folate levels. However, it should be noted that cerebral folate deficiency is also often used to describe conditions where CSF 5-MTHF is low, in the presence of low or undefined peripheral folate levels. Known defects of folate transport are deficiency of the proton coupled folate transporter, associated with systemic as well as cerebral folate deficiency, and deficiency of the folate receptor alpha, leading to an isolated cerebral folate deficiency associated with intractable seizures, developmental delay and/or regression, progressive ataxia and choreoathetoid movement disorders. Inborn errors of folate metabolism include deficiencies of the enzymes methylenetetrahydrofolate reductase, dihydrofolate reductase and 5,10-methenyltetrahydrofolate synthetase. Cerebral folate deficiency is potentially a treatable condition and so prompt recognition of these inborn errors and initiation of appropriate therapy is of paramount importance. Secondary cerebral folate deficiency may be observed in other inherited metabolic diseases, including disorders of the mitochondrial oxidative phosphorylation system, serine deficiency, and pyridoxine dependent epilepsy. Other secondary causes of cerebral folate deficiency include the effects of drugs, immune response activation, toxic insults and oxidative stress. This review describes the absorption, transport and metabolism of folate within the body; analytical methods to measure folate species in blood, plasma and CSF; inherited and acquired causes of cerebral folate deficiency; and possible treatment options in those patients found to have cerebral folate deficiency.
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Affiliation(s)
- Simon Pope
- Neurometabolic Unit, National Hospital for Neurology, London, UK
| | - Rafael Artuch
- Clinical Biochemistry Department, Institut de Recerca Sant Joan de Déu and CIBERER, ISCIII, Barcelona, Spain
| | - Simon Heales
- Neurometabolic Unit, National Hospital for Neurology, London, UK
- Department of Chemical Pathology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
- Mitochondrial Research Group, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Shamima Rahman
- Mitochondrial Research Group, UCL Great Ormond Street Institute of Child Health, London, UK
- Department of Metabolic Medicine, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
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Masingue M, Benoist JF, Roze E, Moussa F, Sedel F, Lubetzki C, Nadjar Y. Cerebral folate deficiency in adults: A heterogeneous potentially treatable condition. J Neurol Sci 2019; 396:112-118. [DOI: 10.1016/j.jns.2018.11.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 10/19/2018] [Accepted: 11/09/2018] [Indexed: 11/16/2022]
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Ebrahimi‐Fakhari D, Van Karnebeek C, Münchau A. Movement Disorders in Treatable Inborn Errors of Metabolism. Mov Disord 2018; 34:598-613. [DOI: 10.1002/mds.27568] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 09/30/2018] [Accepted: 10/25/2018] [Indexed: 12/20/2022] Open
Affiliation(s)
- Darius Ebrahimi‐Fakhari
- Department of Neurology, Boston Children's HospitalHarvard Medical School Boston Massachusetts USA
| | - Clara Van Karnebeek
- Departments of Pediatrics and Clinical GeneticsAmsterdam University Medical Centres Amsterdam The Netherlands
| | - Alexander Münchau
- Department of Pediatric and Adult Movement Disorders and Neuropsychiatry, Institute of NeurogeneticsUniversity of Lübeck Lübeck Germany
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Tabassum S, AlAsmari A, AlSaman AA. Widening the phenotypic spectrum - Non epileptic presentation of folate transporter deficiency. J Clin Neurosci 2018; 59:341-344. [PMID: 30420205 DOI: 10.1016/j.jocn.2018.10.075] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 10/15/2018] [Indexed: 10/27/2022]
Abstract
INTRODUCTION Folate is essential for production of DNA, neurotransmitters and myelin and regulation of genetic activity. A specific transporter protein is required to transport folate from blood to CSF. Various inherited brain-specific folate transport defects have been recognized due to mutation in Folate Receptor alpha (FOLR1). FOLR1 mutation is one of the vitamin responsive encephalopathies and is inherited as an autosomal recessive condition. It has a wide spectrum of phenotype, commonly presenting as epileptic encephalopathy. Less frequently the condition may manifest with subtle hypotonia, movement disorder as tremors, ataxia or intellectual disability and autistic spectrum disorder. We present a case of folate transporter deficiency with non-epileptic manifestations, presenting with tremors, speech delay and stable white matter changes in MRI brain. OBJECTIVE We present a case of Folate transporter defect with Non-epileptic presentation. CONCLUSION Folate transporter deficiency has a wide range of presenting symptoms. Presentation with slowly progressive atypical symptoms, stable white matter changes in brain MRI that does not fit a specific diagnosis, should raise a high suspicion of FOLR1 mutation, even in absence of seizures. Since folate transporter deficiency is a treatable neurodegenerative disorder, early diagnosis and supplementation with folinic acid is vital.
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Affiliation(s)
- Sadia Tabassum
- National Neurosciences Institute, King Fahad Medical City, Riyadh, Saudi Arabia.
| | - Ali AlAsmari
- Department of Medical Genetics, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Abdul Aziz AlSaman
- National Neurosciences Institute, King Fahad Medical City, Riyadh, Saudi Arabia
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Liu J, Tong L, Song S, Niu Y, Li J, Wu X, Zhang J, Zai CC, Luo F, Wu J, Li H, Wong AHC, Sun R, Liu F, Li B. Novel and de novo mutations in pediatric refractory epilepsy. Mol Brain 2018; 11:48. [PMID: 30185235 PMCID: PMC6125990 DOI: 10.1186/s13041-018-0392-5] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 08/27/2018] [Indexed: 12/19/2022] Open
Abstract
Pediatric refractory epilepsy is a broad phenotypic spectrum with great genetic heterogeneity. Next-generation sequencing (NGS) combined with Sanger sequencing could help to understand the genetic diversity and underlying disease mechanisms in pediatric epilepsy. Here, we report sequencing results from a cohort of 172 refractory epilepsy patients aged 0-14 years. The pathogenicity of identified variants was evaluated in accordance with the American College of Medical Genetics and Genomics (ACMG) criteria. We identified 43 pathogenic or likely pathogenic variants in 40 patients (23.3%). Among these variants, 74.4% mutations (32/43) were de novo and 60.5% mutations (26/43) were novel. Patients with onset age of seizures ≤12 months had higher yields of deleterious variants compared to those with onset age of seizures > 12 months (P = 0.006). Variants in ion channel genes accounted for the greatest functional gene category (55.8%), with SCN1A coming first (16/43). 81.25% (13/16) of SCN1A mutations were de novo and 68.8% (11/16) were novel in Dravet syndrome. Pathogenic or likely pathogenic variants were found in the KCNQ2, STXBP1, SCN2A genes in Ohtahara syndrome. Novel deleterious variants were also found in West syndrome, Doose syndrome and glucose transporter type 1 deficiency syndrome patients. One de novo MECP2 mutation were found in a Rett syndrome patient. TSC1/TSC2 variants were found in 60% patients with tuberous sclerosis complex patients. Other novel mutations detected in unclassified epilepsy patients involve the SCN8A, CACNA1A, GABRB3, GABRA1, IQSEC2, TSC1, VRK2, ATP1A2, PCDH19, SLC9A6 and CHD2 genes. Our study provides novel insights into the genetic origins of pediatric epilepsy and represents a starting-point for further investigations into the molecular pathophysiology of pediatric epilepsy that could eventually lead to better treatments.
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Affiliation(s)
- Jing Liu
- Department of Pediatrics, Qilu Hospital of Shandong University, Jinan, Shandong, People's Republic of China.,Shandong University, Jinan, Shandong, People's Republic of China
| | - Lili Tong
- Department of Pediatrics, Qilu Hospital of Shandong University, Jinan, Shandong, People's Republic of China.,Shandong University, Jinan, Shandong, People's Republic of China
| | - Shuangshuang Song
- Qilu Children's hospital of Shandong University, Jinan, Shandong, People's Republic of China
| | - Yue Niu
- Department of Pediatrics, Qilu Hospital of Shandong University, Jinan, Shandong, People's Republic of China.,Shandong University, Jinan, Shandong, People's Republic of China
| | - Jun Li
- Department of Pediatrics, Qilu Hospital of Shandong University, Jinan, Shandong, People's Republic of China.,Shandong University, Jinan, Shandong, People's Republic of China
| | - Xiu Wu
- Department of Pediatrics, Qilu Hospital of Shandong University, Jinan, Shandong, People's Republic of China.,Shandong University, Jinan, Shandong, People's Republic of China
| | - Jie Zhang
- MyGenostics Inc., Beijing, People's Republic of China
| | - Clement C Zai
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, University of Toronto, Toronto, ON, Canada
| | - Fang Luo
- MyGenostics Inc., Beijing, People's Republic of China
| | - Jian Wu
- MyGenostics Inc., Beijing, People's Republic of China
| | - Haiyin Li
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, University of Toronto, Toronto, ON, Canada
| | - Albert H C Wong
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, University of Toronto, Toronto, ON, Canada
| | - Ruopeng Sun
- Department of Pediatrics, Qilu Hospital of Shandong University, Jinan, Shandong, People's Republic of China.,Shandong University, Jinan, Shandong, People's Republic of China
| | - Fang Liu
- Shandong University, Jinan, Shandong, People's Republic of China.,Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, University of Toronto, Toronto, ON, Canada
| | - Baomin Li
- Department of Pediatrics, Qilu Hospital of Shandong University, Jinan, Shandong, People's Republic of China. .,Shandong University, Jinan, Shandong, People's Republic of China.
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14
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Balashova OA, Visina O, Borodinsky LN. Folate action in nervous system development and disease. Dev Neurobiol 2018; 78:391-402. [PMID: 29380544 DOI: 10.1002/dneu.22579] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 01/24/2018] [Accepted: 01/24/2018] [Indexed: 01/04/2023]
Abstract
The vitamin folic acid has been recognized as a crucial environmental factor for nervous system development. From the early fetal stages of the formation of the presumptive spinal cord and brain to the maturation and maintenance of the nervous system during infancy and childhood, folate levels and its supplementation have been considered influential in the clinical outcome of infants and children affected by neurological diseases. Despite the vast epidemiological information recorded on folate function and neural tube defects, neural development and neurodegenerative diseases, the mechanisms of folate action in the developing neural tissue have remained elusive. Here we compiled studies that argue for a unique role for folate in nervous system development and function and its consequences to neural disease and repair. © 2018 Wiley Periodicals, Inc. Develop Neurobiol 78: 391-402, 2018.
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Affiliation(s)
- Olga A Balashova
- Department of Physiology & Membrane Biology and Institute for Pediatric Regenerative Medicine, Shriners Hospital for Children, University of California Davis School of Medicine, Sacramento, California
| | - Olesya Visina
- Department of Physiology & Membrane Biology and Institute for Pediatric Regenerative Medicine, Shriners Hospital for Children, University of California Davis School of Medicine, Sacramento, California
| | - Laura N Borodinsky
- Department of Physiology & Membrane Biology and Institute for Pediatric Regenerative Medicine, Shriners Hospital for Children, University of California Davis School of Medicine, Sacramento, California
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15
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Desai M, Chauhan J. Analysis of polymorphisms in genes involved in folate metabolism and its impact on Down syndrome and other intellectual disability. Meta Gene 2017. [DOI: 10.1016/j.mgene.2017.07.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
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16
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Fung KYY, Fairn GD, Lee WL. Transcellular vesicular transport in epithelial and endothelial cells: Challenges and opportunities. Traffic 2017; 19:5-18. [PMID: 28985008 DOI: 10.1111/tra.12533] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 09/29/2017] [Accepted: 09/29/2017] [Indexed: 12/31/2022]
Abstract
Vesicle-mediated transcellular transport or simply "transcytosis" is a cellular process used to shuttle macromolecules such as lipoproteins, antibodies, and albumin from one surface of a polarized cell to the other. This mechanism is in contrast to the transit of small molecules such as anions, cations and amino acids that occur via uptake, diffusion through the cytosol and release and is also distinct from paracellular leak between cells. Importantly, transcytosis has evolved as a process to selectively move macromolecules between 2 neighboring yet unique microenvironments within a multicellular organism. Examples include the movement of lipoproteins out of the circulatory system and into tissues and the delivery of immunoglobulins to mucosal surfaces. Regardless of whether the transport is conducted by endothelial or epithelial cells, the process often involves receptor-mediated uptake of a ligand into an endocytic vesicle, regulated transit of the carrier through the cytoplasm and release of the cargo via an exocytic event. While transcytosis has been examined in detail in epithelial cells, for both historical and technical reasons, the process is less understood in endothelial cells. Here, we spotlight aspects of epithelial transcytosis including recent findings and review the comparative dearth of knowledge regarding the process in endothelial cells highlighting the opportunity for further study.
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Affiliation(s)
- Karen Y Y Fung
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario, Canada.,Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Gregory D Fairn
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario, Canada.,Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada.,Department of Surgery & Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada.,Institute for Biomedical Engineering and Science Technology (iBEST), Ryerson University and St Michael's Hospital, Toronto, Ontario, Canada
| | - Warren L Lee
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario, Canada.,Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada.,Institute for Biomedical Engineering and Science Technology (iBEST), Ryerson University and St Michael's Hospital, Toronto, Ontario, Canada.,Departments of Medicine, Laboratory Medicine and Pathobiology,& Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
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17
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Weng Q, Wang J, Wang J, Tan B, Wang J, Wang H, Zheng T, Lu QR, Yang B, He Q. Folate Metabolism Regulates Oligodendrocyte Survival and Differentiation by Modulating AMPKα Activity. Sci Rep 2017; 7:1705. [PMID: 28496133 PMCID: PMC5431811 DOI: 10.1038/s41598-017-01732-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 04/03/2017] [Indexed: 01/13/2023] Open
Abstract
Folate, an essential micronutrient, is a critical cofactor in one-carbon metabolism for many cellular pathways including DNA synthesis, metabolism and maintenance. Folate deficiency has been associated with an increased risk of neurological disease, cancer and cognitive dysfunction. Dihydrofolate reductase (DHFR) is a key enzyme to regulate folate metabolism, however folate/DHFR activity in oligodendrocyte development has not been fully understood. Here we show that folate enhances oligodendrocyte maturation both in vitro and in vivo, which is accompanied with upregulation of oligodendrocyte-specific DHFR expression. On the other hand, pharmacological inhibition of DHFR by methotrexate (MTX) causes severe defects in oligodendrocyte survival and differentiation, which could be reversed by folate intake. We further demonstrate that folate activates a metabolic regulator AMPKα to promote oligodendrocyte survival and differentiation. Moreover, activation of AMPKα partially rescues oligodendrocyte defects caused by DHFR-inhibition both in vitro and in vivo. Taken together, these findings identify a previously uncharacterized role of folate/DHFR/AMPKα axis in regulating oligodendrocyte survival and myelination during CNS development.
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Affiliation(s)
- Qinjie Weng
- Institute of Pharmacology & Toxicology, Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China.,Center for drug safety Evaluation and Research, Zhejiang University, Hangzhou, China
| | - Jiajia Wang
- Institute of Pharmacology & Toxicology, Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Jiaying Wang
- Institute of Pharmacology & Toxicology, Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Biqin Tan
- Institute of Pharmacology & Toxicology, Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Jing Wang
- Institute of Pharmacology & Toxicology, Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Haibo Wang
- Department of Pediatrics, Brain Tumor Center, Cancer and Blood Disease Institute, Cincinnati Children's Hospital Medical Center, OH, USA
| | - Tao Zheng
- School of Preclinical and Forensic Medicine, West China Second Hospital, Sichuan University, Chengdu, China
| | - Q Richard Lu
- Department of Pediatrics, Brain Tumor Center, Cancer and Blood Disease Institute, Cincinnati Children's Hospital Medical Center, OH, USA
| | - Bo Yang
- Institute of Pharmacology & Toxicology, Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China.
| | - Qiaojun He
- Institute of Pharmacology & Toxicology, Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China. .,Center for drug safety Evaluation and Research, Zhejiang University, Hangzhou, China.
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18
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Krsička D, Geryk J, Vlčková M, Havlovicová M, Macek M, Pourová R. Identification of likely associations between cerebral folate deficiency and complex genetic- and metabolic pathogenesis of autism spectrum disorders by utilization of a pilot interaction modeling approach. Autism Res 2017; 10:1424-1435. [DOI: 10.1002/aur.1780] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 02/01/2017] [Accepted: 02/23/2017] [Indexed: 12/12/2022]
Affiliation(s)
- Daniel Krsička
- Department of Biology and Medical Genetics, 2nd Faculty of Medicine; Charles University and University Hospital Motol; V Úvalu 84, 150 06 Prague Czech Republic
| | - Jan Geryk
- Department of Biology and Medical Genetics, 2nd Faculty of Medicine; Charles University and University Hospital Motol; V Úvalu 84, 150 06 Prague Czech Republic
| | - Markéta Vlčková
- Department of Biology and Medical Genetics, 2nd Faculty of Medicine; Charles University and University Hospital Motol; V Úvalu 84, 150 06 Prague Czech Republic
| | - Markéta Havlovicová
- Department of Biology and Medical Genetics, 2nd Faculty of Medicine; Charles University and University Hospital Motol; V Úvalu 84, 150 06 Prague Czech Republic
| | - Milan Macek
- Department of Biology and Medical Genetics, 2nd Faculty of Medicine; Charles University and University Hospital Motol; V Úvalu 84, 150 06 Prague Czech Republic
| | - Radka Pourová
- Department of Biology and Medical Genetics, 2nd Faculty of Medicine; Charles University and University Hospital Motol; V Úvalu 84, 150 06 Prague Czech Republic
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19
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Kobayashi Y, Tohyama J, Akiyama T, Magara S, Kawashima H, Akasaka N, Nakashima M, Saitsu H, Matsumoto N. Severe leukoencephalopathy with cortical involvement and peripheral neuropathy due to FOLR1 deficiency. Brain Dev 2017; 39:266-270. [PMID: 27743887 DOI: 10.1016/j.braindev.2016.09.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2016] [Revised: 09/22/2016] [Accepted: 09/25/2016] [Indexed: 11/24/2022]
Abstract
Cerebral folate deficiency due to folate receptor 1 gene (FOLR1) mutations is an autosomal recessive disorder resulting from a brain-specific folate transport defect. It is characterized by late infantile onset, severe psychomotor regression, epilepsy, and leukodystrophy. We describe a consanguineous girl exhibiting severe developmental regression, intractable epilepsy, polyneuropathy, and profound hypomyelination with cortical involvement. Magnetic resonance imaging showed cortical disturbances in addition to profound hypomyelination and cerebellar atrophy. Nerve conduction studies revealed both axonal degeneration and demyelinating features. A diagnosis of cerebral folate deficiency was confirmed by a homozygous c.466T>G (p.W156G) mutation in FOLR1, coupled with extremely low cerebrospinal fluid levels of 5-methyltetrahydrofolate. Her symptoms, neuroradiological findings, and polyneuropathy were alleviated by oral folinic acid treatment in conjunction with intravenous and intramuscular administration therapy. Our patient shows that folinic acid therapy can ameliorate the clinical symptoms, white matter disturbances, cortical insults, and peripheral neuropathy of cerebral folate deficiency caused by FOLR1 mutation. It is important to recognize these clinical symptoms and make a precise diagnosis early on, because cerebral folate deficiency is treatable.
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Affiliation(s)
- Yu Kobayashi
- Department of Child Neurology, Nishi-Niigata Chuo National Hospital, Japan.
| | - Jun Tohyama
- Department of Child Neurology, Nishi-Niigata Chuo National Hospital, Japan; Niigata University Medical and Dental Hospital, Japan
| | - Tomoyuki Akiyama
- Department of Child Neurology, Okayama University Hospital, Japan
| | - Shinichi Magara
- Department of Child Neurology, Nishi-Niigata Chuo National Hospital, Japan
| | - Hideshi Kawashima
- Department of Child Neurology, Nishi-Niigata Chuo National Hospital, Japan
| | - Noriyuki Akasaka
- Department of Child Neurology, Nishi-Niigata Chuo National Hospital, Japan
| | - Mitsuko Nakashima
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Japan
| | - Hirotomo Saitsu
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Japan
| | - Naomichi Matsumoto
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Japan
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20
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Folate nutrition and blood-brain barrier dysfunction. Curr Opin Biotechnol 2017; 44:146-152. [PMID: 28189938 DOI: 10.1016/j.copbio.2017.01.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 01/09/2017] [Accepted: 01/12/2017] [Indexed: 01/30/2023]
Abstract
Mammals require essential nutrients from dietary sources to support normal metabolic, physiological and neuronal functions, to prevent diseases of nutritional deficiency as well as to prevent chronic disease. Disease and/or its treatment can modify fundamental biological processes including cellular nutrient accretion, stability and function in cells. These effects can be isolated to a specific diseased organ in the absence of whole-body alterations in nutrient status or biochemistry. Loss of blood-brain barrier function, which occurs in in-born errors of metabolism and in chronic disease, can cause brain-specific folate deficiency and contribute to disease co-morbidity. The role of brain folate deficiency in neuropsychiatric disorders is reviewed, as well as emerging diagnostic and nutritional strategies to identify and address brain folate deficiency in blood-brain barrier dysfunction.
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21
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Karin I, Borggraefe I, Catarino CB, Kuhm C, Hoertnagel K, Biskup S, Opladen T, Blau N, Heinen F, Klopstock T. Folinic acid therapy in cerebral folate deficiency: marked improvement in an adult patient. J Neurol 2017; 264:578-582. [PMID: 28054128 DOI: 10.1007/s00415-016-8387-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 12/24/2016] [Accepted: 12/26/2016] [Indexed: 11/25/2022]
Affiliation(s)
- Ivan Karin
- Department of Neurology, Friedrich-Baur-Institute, University of Munich, Ziemssenstr. 1, 80336, Munich, Germany. .,German Network for Mitochondrial Disorders (mitoNET), Munich, Germany.
| | - Ingo Borggraefe
- Department of Pediatric Neurology, Developmental Medicine and Social Pediatrics, University of Munich, Munich, Germany
| | - Claudia B Catarino
- Department of Neurology, Friedrich-Baur-Institute, University of Munich, Ziemssenstr. 1, 80336, Munich, Germany.,German Network for Mitochondrial Disorders (mitoNET), Munich, Germany
| | - Christoph Kuhm
- Department of Neurology, Friedrich-Baur-Institute, University of Munich, Ziemssenstr. 1, 80336, Munich, Germany.,German Network for Mitochondrial Disorders (mitoNET), Munich, Germany
| | | | - Saskia Biskup
- CeGaT GmbH, Center for Genomics and Transcriptomics, Tübingen, Germany
| | - Thomas Opladen
- Division of Inborn Metabolic Diseases, University Children's Hospital, Heidelberg, Germany
| | - Nenad Blau
- Division of Inborn Metabolic Diseases, University Children's Hospital, Heidelberg, Germany
| | - Florian Heinen
- Department of Pediatric Neurology, Developmental Medicine and Social Pediatrics, University of Munich, Munich, Germany
| | - Thomas Klopstock
- Department of Neurology, Friedrich-Baur-Institute, University of Munich, Ziemssenstr. 1, 80336, Munich, Germany.,German Network for Mitochondrial Disorders (mitoNET), Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.,DZNE-German Center for Neurodegenerative Diseases, Munich, Germany
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22
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Batllori M, Molero-Luis M, Casado M, Sierra C, Artuch R, Ormazabal A. Biochemical Analyses of Cerebrospinal Fluid for the Diagnosis of Neurometabolic Conditions. What Can We Expect? Semin Pediatr Neurol 2016; 23:273-284. [PMID: 28284389 DOI: 10.1016/j.spen.2016.11.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
In this article, we review the state-of-the-art analysis of different biomarkers in the cerebrospinal fluid for the diagnosis of genetically conditioned, rare, neurometabolic diseases, including glucose transport defects, neurotransmitter (dopamine, serotonin, and gamma-aminobutyric acid) and pterin deficiencies, and vitamin defects (folate, vitamin B6, and thiamine) that affect the brain. The analysis of several key metabolites are detailed, which thus highlights the preanalytical and analytical factors that should be cautiously controlled to avoid misdiagnosis; moreover, these factors may facilitate an adequate interpretation of the biochemical profiles in the context of severe neuropediatric disorders. Secondary disturbances in these biomarkers, which are associated with other genetic or environmental conditions, are also detailed. Importantly, the early biochemical identification of biochemical disturbances in the cerebrospinal fluid may improve the clinical outcomes of a remarkable number of patients, who may exhibit good neurologic outcomes using the available therapies for these disorders.
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Affiliation(s)
- Marta Batllori
- Clinical Biochemistry Department, Centre for Biomedical Research on Rare Disease (CIBERER-ISCIII), Pediatric Research Institute, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Marta Molero-Luis
- Clinical Biochemistry Department, Centre for Biomedical Research on Rare Disease (CIBERER-ISCIII), Pediatric Research Institute, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Mercedes Casado
- Clinical Biochemistry Department, Centre for Biomedical Research on Rare Disease (CIBERER-ISCIII), Pediatric Research Institute, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Cristina Sierra
- Clinical Biochemistry Department, Centre for Biomedical Research on Rare Disease (CIBERER-ISCIII), Pediatric Research Institute, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Rafael Artuch
- Clinical Biochemistry Department, Centre for Biomedical Research on Rare Disease (CIBERER-ISCIII), Pediatric Research Institute, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Aida Ormazabal
- Clinical Biochemistry Department, Centre for Biomedical Research on Rare Disease (CIBERER-ISCIII), Pediatric Research Institute, Hospital Sant Joan de Déu, Barcelona, Spain.
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23
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Ortigoza Escobar JD, Pérez Dueñas B. Treatable Inborn Errors of Metabolism Due to Membrane Vitamin Transporters Deficiency. Semin Pediatr Neurol 2016; 23:341-350. [PMID: 28284395 DOI: 10.1016/j.spen.2016.11.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
B vitamins act as cofactors for strategic metabolic processes. The SLC19 gene family of solute carriers has a significant structural similarity, transporting substrates with different structure and ionic charge. Three proteins of this family are expressed ubiquitously and mediate the transport of 2 important water-soluble vitamins, folate, and thiamine. SLC19A1 transports folate and SLC19A2 and SLC19A3 transport thiamine. PCFT and FOLR1 ensure intestinal absorption and transport of folate through the blood-brain barrier and SLC19A25 transports thiamine into the mitochondria. Several damaging genetic defects in vitamin B transport and metabolism have been reported. The most relevant feature of thiamine and folate transport defects is that both of them are treatable disorders. In this article, we discuss the biology and transport of thiamine and folate, as well as the clinical phenotype of the genetic defects.
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Affiliation(s)
- Juan Darío Ortigoza Escobar
- Department of Child Neurology, Pediatric Research Institute, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain; Centre for Biomedical Research on Rare Diseases (CIBERER), Institute of Health Carlos III, Madrid, Spain
| | - Belén Pérez Dueñas
- Department of Child Neurology, Pediatric Research Institute, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain; Centre for Biomedical Research on Rare Diseases (CIBERER), Institute of Health Carlos III, Madrid, Spain.
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24
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Zhao R, Aluri S, Goldman ID. The proton-coupled folate transporter (PCFT-SLC46A1) and the syndrome of systemic and cerebral folate deficiency of infancy: Hereditary folate malabsorption. Mol Aspects Med 2016; 53:57-72. [PMID: 27664775 DOI: 10.1016/j.mam.2016.09.002] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 09/18/2016] [Indexed: 02/07/2023]
Abstract
The proton-coupled folate transporter (PCFT-SLC46A1) is the mechanism by which folates are absorbed across the brush-border membrane of the small intestine. The transporter is also expressed in the choroid plexus and is required for transport of folates into the cerebrospinal fluid. Loss of PCFT function, as occurs in the autosomal recessive disorder "hereditary folate malabsorption" (HFM), results in a syndrome characterized by severe systemic and cerebral folate deficiency. Folate-receptor alpha (FRα) is expressed in the choroid plexus, and loss of function of this protein, as also occurs in an autosomal recessive disorder, results solely in "cerebral folate deficiency" (CFD), the designation for this disorder. This paper reviews the current understanding of the functional and structural properties and regulation of PCFT, an electrogenic proton symporter, and contrasts PCFT properties with those of the reduced folate carrier (RFC), an organic anion antiporter, that is the major route of folate transport to systemic tissues. The clinical characteristics of HFM and its treatment, based upon the thirty-seven known cases with the clinical syndrome, of which thirty have been verified by genotype, are presented. The ways in which PCFT and FRα might interact at the level of the choroid plexus such that each is required for folate transport from blood to cerebrospinal fluid are considered along with the different clinical presentations of HFM and CFD.
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Affiliation(s)
- Rongbao Zhao
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York, USA; Department of Medicine, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Srinivas Aluri
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York, USA; Department of Medicine, Albert Einstein College of Medicine, Bronx, New York, USA
| | - I David Goldman
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York, USA; Department of Medicine, Albert Einstein College of Medicine, Bronx, New York, USA.
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25
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Delmelle F, Thöny B, Clapuyt P, Blau N, Nassogne MC. Neurological improvement following intravenous high-dose folinic acid for cerebral folate transporter deficiency caused by FOLR-1 mutation. Eur J Paediatr Neurol 2016; 20:709-13. [PMID: 27328863 DOI: 10.1016/j.ejpn.2016.05.021] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Revised: 03/25/2016] [Accepted: 05/31/2016] [Indexed: 02/09/2023]
Abstract
BACKGROUND Cerebral folate transporter deficiency caused by FOLR-1 mutations has been described in 2009. This condition is characterized by a 5MTHF level <5 nmol/l in the CSF, along with regression of acquisition in the second year of life, ataxia, and refractory myoclonic epilepsy. Oral or intravenous folinic acid (5-formyltetrahydrofolate) treatment has been shown to improve clinical status. CASE PRESENTATION We present the cases of two sisters with cerebral folate transport deficiency caused by mutation in the folate receptor 1 (FOLR1) gene (MIM *136430). Following recommendations, we administered oral folinic acid at 5 mg/kg/day, resulting in some initial clinical improvement, yet severe epilepsy persisted. During treatment, cerebrospinal fluid (CSF) analysis revealed normal 5-methyltetrahydrofolate (5MTHF) levels (60.1 nmol/l; normal range: 53-182 nmol/l). Epilepsy proved difficult to control and the younger patient exhibited neurological regression. We then administered high-dose folinic acid intravenously over 3 days (6 mg/kg/day for 24 h, then 12 mg/kg/day for 48 h), which significantly improved clinical status and epilepsy. CSF analysis revealed high 5MTHF levels following intravenous infusion (180 nmol/l). Treatment continued with monthly intravenous administrations of 20-25 mg/kg folinic acid. At 2 years post-treatment, clinical improvement was confirmed. CONCLUSIONS This report illustrates that cerebral folate transporter deficiency caused by FOLR-1 mutations is a treatable condition and can potentially be cured by folinic acid treatment. As already reported, early effective treatment is known to improve outcomes in affected children. In our study, intravenous high-dose folinic acid infusions appeared to optimize clinical response.
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Affiliation(s)
- Françoise Delmelle
- Université Catholique de Louvain, Cliniques Universitaires Saint-Luc, Brussels, Belgium
| | - Beat Thöny
- Division of Metabolism, University Children's Hospital, Zürich, Switzerland
| | - Philippe Clapuyt
- Université Catholique de Louvain, Cliniques Universitaires Saint-Luc, Brussels, Belgium
| | - Nenad Blau
- University Children's Hospital, Division of Inborn Metabolic Diseases, Department of General Pediatrics, Heidelberg, Germany
| | - Marie-Cécile Nassogne
- Université Catholique de Louvain, Cliniques Universitaires Saint-Luc, Brussels, Belgium.
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26
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Marcián V, Filip P, Bareš M, Brázdil M. Cerebellar Dysfunction and Ataxia in Patients with Epilepsy: Coincidence, Consequence, or Cause? TREMOR AND OTHER HYPERKINETIC MOVEMENTS (NEW YORK, N.Y.) 2016; 6:376. [PMID: 27375960 PMCID: PMC4925921 DOI: 10.7916/d8kh0nbt] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Accepted: 05/05/2016] [Indexed: 12/15/2022]
Abstract
Basic epilepsy teachings assert that seizures arise from the cerebral cortex, glossing over infratentorial structures such as the cerebellum that are believed to modulate rather than generate seizures. Nonetheless, ataxia and other clinical findings in epileptic patients are slowly but inevitably drawing attention to this neural node. Tracing the evolution of this line of inquiry from the observed coincidence of cerebellar atrophy and cerebellar dysfunction (most apparently manifested as ataxia) in epilepsy to their close association, this review considers converging clinical, physiological, histological, and neuroimaging evidence that support incorporating the cerebellum into epilepsy pathology. We examine reports of still controversial cerebellar epilepsy, studies of cerebellar stimulation alleviating paroxysmal epileptic activity, studies and case reports of cerebellar lesions directly associated with seizures, and conditions in which ataxia is accompanied by epileptic seizures. Finally, the review substantiates the role of this complex brain structure in epilepsy whether by coincidence, as a consequence of deleterious cortical epileptic activity or antiepileptic drugs, or the very cause of the disease.
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Affiliation(s)
- Václav Marcián
- First Department of Neurology, St. Anne's University Hospital, Brno, Czech Republic; Medical Faculty of Masaryk University, Brno, Czech Republic.,First Department of Neurology, St. Anne's University Hospital, Brno, Czech Republic; Medical Faculty of Masaryk University, Brno, Czech Republic; Behavioral and Social Neuroscience Research Group, CEITEC (Central European Institute of Technology), Masaryk University, Brno, Czech Republic; Department of Neurology, School of Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Pavel Filip
- First Department of Neurology, St. Anne's University Hospital, Brno, Czech Republic; Medical Faculty of Masaryk University, Brno, Czech Republic
| | - Martin Bareš
- First Department of Neurology, St. Anne's University Hospital, Brno, Czech Republic; Medical Faculty of Masaryk University, Brno, Czech Republic; Behavioral and Social Neuroscience Research Group, CEITEC (Central European Institute of Technology), Masaryk University, Brno, Czech Republic; Department of Neurology, School of Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Milan Brázdil
- First Department of Neurology, St. Anne's University Hospital, Brno, Czech Republic; Medical Faculty of Masaryk University, Brno, Czech Republic; Behavioral and Social Neuroscience Research Group, CEITEC (Central European Institute of Technology), Masaryk University, Brno, Czech Republic
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27
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Molero-Luis M, Serrano M, O’Callaghan MM, Sierra C, Pérez-Dueñas B, García-Cazorla A, Artuch R. Clinical, etiological and therapeutic aspects of cerebral folate deficiency. Expert Rev Neurother 2015; 15:793-802. [DOI: 10.1586/14737175.2015.1055322] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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28
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Choroid plexus transcytosis and exosome shuttling deliver folate into brain parenchyma. Nat Commun 2013; 4:2123. [PMID: 23828504 DOI: 10.1038/ncomms3123] [Citation(s) in RCA: 221] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 06/07/2013] [Indexed: 12/19/2022] Open
Abstract
Loss of folate receptor-α function is associated with cerebral folate transport deficiency and childhood-onset neurodegeneration. To clarify the mechanism of cerebral folate transport at the blood-cerebrospinal fluid barrier, we investigate the transport of 5-methyltetrahydrofolate in polarized cells. Here we identify folate receptor-α-positive intralumenal vesicles within multivesicular bodies and demonstrate the directional cotransport of human folate receptor-α, and labelled folate from the basolateral to the apical membrane in rat choroid plexus cells. Both the apical medium of folate receptor-α-transfected rat choroid plexus cells and human cerebrospinal fluid contain folate receptor-α-positive exosomes. Loss of folate receptor-α-expressing cerebrospinal fluid exosomes correlates with severely reduced 5-methyltetrahydrofolate concentration, corroborating the importance of the folate receptor-α-mediated folate transport in the cerebrospinal fluid. Intraventricular injections of folate receptor-α-positive and -negative exosomes into mouse brains demonstrate folate receptor-α-dependent delivery of exosomes into the brain parenchyma. Our results unravel a new pathway of folate receptor-α-dependent exosome-mediated folate delivery into the brain parenchyma and opens new avenues for cerebral drug targeting.
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29
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Abstract
Seizures may be the first and the major presenting feature of an inborn error of metabolism (IEM), for example in a neonate with pyridoxine-dependent epilepsy. In other IEMs, seizures may be preceded by other major symptoms: by a reduced level of consciousness in a child with an organic acidaemia or urea cycle defect; or by loss of skills, progressive weakness, ataxia, and upper motor signs in a child with a lysosomal storage disorder or peroxisomal leukodystrophy. This review concentrates on those IEMs for which specific treatment is available. The common metabolic causes of seizures vary according to the age at presentation. Features from the history, examination, imaging, and first line biochemical investigations can all provide clues to an inborn error. This review attempts to delineate these and to provide a guide to the specific tests that can be used to make the diagnosis of disorders with specific treatment.
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Affiliation(s)
- Shamima Rahman
- Clinical and Molecular Genetics and Neurosciences Units, University College London Institute of Child Health, London and Metabolic and Neurosciences Units, Great Ormond Street Hospital for Children NHS Trust, London, UK.
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30
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Wang X, Cabrera RM, Li Y, Miller DS, Finnell RH. Functional regulation of P-glycoprotein at the blood-brain barrier in proton-coupled folate transporter (PCFT) mutant mice. FASEB J 2012; 27:1167-75. [PMID: 23212123 DOI: 10.1096/fj.12-218495] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Folate deficiency has been associated with many adverse clinical manifestations. The blood-brain barrier (BBB), formed by brain capillary endothelial cells, protects the brain from exposure to neurotoxicants. The function of BBB is modulated by multiple ABC transporters, particularly P-glycoprotein. A proton-coupled folate transporter (PCFT)-deficient mouse has been previously described as a model for systemic folate deficiency. Herein, we demonstrate that exposing mouse brain capillaries to the antiepileptic drug, valproic acid (VPA; 5 μM), significantly increased P-glycoprotein transport function in the wild-type animals. A ligand to the aryl hydrocarbon receptor, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), produced a similar induction of P-glycoprotein, which tightened the BBB, thereby increasing the neuroprotection. However, VPA- or TCDD-induced P-glycoprotein transport was blocked in the PCFT-nullizygous mice, indicating that multiple neuroprotective mechanisms are compromised under folate-deficient conditions. Brain capillaries from S-folinic acid (SFA; 40 mg/kg)-treated PCFT-nullizygous mice exhibited increased P-glycoprotein transport following VPA exposure. This suggests that SFA supplementation restored the normal BBB function. In addition, we show that tight-junction proteins are disintegrated in the PCFT mutant mice. Taken together, these findings strongly suggest that folate deficiency disrupts the BBB function by targeting the transporter and tight junctions, which may contribute to the development of neurological disorders.
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Affiliation(s)
- Xueqian Wang
- Department of Nutritional Sciences, Dell Pediatric Research Institute, The University of Texas at Austin, Austin, TX 78723, USA
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31
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Serrano M, Pérez-Dueñas B, Montoya J, Ormazabal A, Artuch R. Genetic causes of cerebral folate deficiency: clinical, biochemical and therapeutic aspects. Drug Discov Today 2012; 17:1299-306. [DOI: 10.1016/j.drudis.2012.07.008] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Revised: 05/18/2012] [Accepted: 07/17/2012] [Indexed: 11/26/2022]
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32
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Steele SU, Cheah SM, Veerapandiyan A, Gallentine W, Smith EC, Mikati MA. Electroencephalographic and seizure manifestations in two patients with folate receptor autoimmune antibody-mediated primary cerebral folate deficiency. Epilepsy Behav 2012; 24:507-12. [PMID: 22749608 DOI: 10.1016/j.yebeh.2012.05.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Revised: 05/26/2012] [Accepted: 05/29/2012] [Indexed: 11/17/2022]
Abstract
Seizure semiology and electroencephalographic (EEG) manifestations of autoimmune-mediated cerebral folate deficiency (CFD) before and after therapy have yet to be fully characterized. Here, we report these findings in two such patients. Our first patient presented with the novel manifestation of infantile spasms at the age of 3months, while the second developed the previously reported initial onset of tonic seizures with static developmental delay, but subsequently manifested the novel finding of electrical status epilepticus in sleep at the age of 15years. Awareness of these new manifestations, together with the previously reported manifestations of developmental delay, seizure onset during the first 2years of life, occurrence of tonic, myoclonic-astatic, absence, and generalized tonic-clonic seizures, with an EEG of generalized spike-slow waves and multifocal spikes, is important to increase the index of suspicion of this treatable disorder.
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Affiliation(s)
- Sonya U Steele
- Division of Pediatric Neurology, Duke University Medical Center, Children's Health Center, 2301 Erwin Road, Durham, NC 27710, USA
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33
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Watkins D, Rosenblatt DS. Update and new concepts in vitamin responsive disorders of folate transport and metabolism. J Inherit Metab Dis 2012; 35:665-70. [PMID: 22108709 DOI: 10.1007/s10545-011-9418-1] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Revised: 10/26/2011] [Accepted: 10/28/2011] [Indexed: 10/15/2022]
Abstract
Derivatives of folic acid are involved in transfer of one-carbon units in cellular metabolism, playing a role in synthesis of purines and thymidylate and in the remethylation of homocysteine to form methionine. Five inborn errors affecting folate transport and metabolism have been well studied: hereditary folate malabsorption, caused by mutations in the gene encoding the proton-coupled folate transporter (SLC46A1); glutamate formiminotransferase deficiency, caused by mutations in the FTCD gene; methylenetetrahydrofolate reductase deficiency, caused by mutations in the MTHFR gene; and functional methionine synthase deficiency, either as the result of mutations affecting methionine synthase itself (cblG, caused by mutations in the MTR gene) or affecting the accessory protein methionine synthase reductase (cblE, caused by mutations in the MTRR gene). Recently additional inborn errors have been identified. Cerebral folate deficiency is a clinically heterogeneous disorder, which in a few families is caused by mutations in the FOLR1 gene. Dihydrofolate reductase deficiency is characterized by megaloblastic anemia and cerebral folate deficiency, with variable neurological findings. It is caused by mutations in the DHFR gene. Deficiency in the trifunctional enzyme containing methylenetetrahydrofolate dehydrogenase, methenyltetrahydrofolate cyclohydrolase and formyltetrahydrofolate synthetase activities, has been identified in a single patient with megaloblastic anemia, atypical hemolytic uremic syndrome and severe combined immune deficiency. It is caused by mutations in the MTHFD1 gene.
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Affiliation(s)
- David Watkins
- The Hess B and Diane Finestone Laboratory in Memory of Jacob and Jenny Finestone, and Department of Human Genetics, McGill University Health Centre, 1650 Cedar Avenue, Room L3-319, Montreal, QC, Canada.
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34
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A compound heterozygous missense mutation and a large deletion in the KCTD7 gene presenting as an opsoclonus-myoclonus ataxia-like syndrome. J Neurol 2012; 259:2590-8. [DOI: 10.1007/s00415-012-6545-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Revised: 05/01/2012] [Accepted: 05/03/2012] [Indexed: 12/14/2022]
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35
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Grapp M, Just IA, Linnankivi T, Wolf P, Lücke T, Häusler M, Gärtner J, Steinfeld R. Molecular characterization of folate receptor 1 mutations delineates cerebral folate transport deficiency. ACTA ACUST UNITED AC 2012; 135:2022-31. [PMID: 22586289 DOI: 10.1093/brain/aws122] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Cerebral folate transport deficiency is an inherited brain-specific folate transport defect that is caused by mutations in the folate receptor 1 gene coding for folate receptor alpha (FRα). This genetic defect gives rise to a progressive neurological disorder with late infantile onset. We screened 72 children with low 5-methyltetrahydrofolate concentrations in the cerebrospinal fluid and neurological symptoms that developed after infancy. We identified nucleotide alterations in the folate receptor 1 gene in 10 individuals who shared developmental regression, ataxia, profound cerebral hypomyelination and cerebellar atrophy. We found four novel pathogenic alleles, one splice mutation and three missense mutations. Heterologous expression of the missense mutations, including previously described mutants, revealed minor decrease in protein expression but loss of cell surface localization, mistargeting to intracellular compartments and thus absence of cellular binding of folic acid. These results explain the functional loss of folate receptor alpha for all detected folate receptor 1 mutations. Three individuals presenting a milder clinical phenotype revealed very similar biochemical and brain imaging data but partially shared pathogenic alleles with more severely affected patients. Thus, our studies suggest that different clinical severities do not necessarily correlate with residual function of folate receptor alpha mutants and indicate that additional factors contribute to the clinical phenotype in cerebral folate transport deficiency.
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Affiliation(s)
- M Grapp
- Department of Paediatrics and Paediatric Neurology, University Medical Centre Göttingen, Germany
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36
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Dill P, Schneider J, Weber P, Trachsel D, Tekin M, Jakobs C, Thöny B, Blau N. Pyridoxal phosphate-responsive seizures in a patient with cerebral folate deficiency (CFD) and congenital deafness with labyrinthine aplasia, microtia and microdontia (LAMM). Mol Genet Metab 2011; 104:362-8. [PMID: 21752681 DOI: 10.1016/j.ymgme.2011.05.019] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2011] [Accepted: 05/30/2011] [Indexed: 12/21/2022]
Abstract
We present an 8-year-old boy with folate receptor alpha (FRα) defect and congenital deafness with labyrinthine aplasia, microtia and microdontia (LAMM syndrome). Both conditions are exceptionally rare autosomal recessive inherited diseases mapped to 11q13. Our patient was found to have novel homozygous nonsense mutations in the FOLR1 gene (p.R204X), and FGF3 gene (p.C50X). While the FRα defect is a disorder of brain-specific folate transport accompanied with cerebral folate deficiency (CFD) causing progressive neurological symptoms, LAMM syndrome is a solely malformative condition, with normal physical growth and cognitive development. Our patient presented with congenital deafness, hypotonia, dysphygia and ataxia in early childhood. At the age of 6 years he developed intractable epilepsy, and deteriorated clinically with respiratory arrest and severe hypercapnea at the age of 8 years. In contrast to the previously published patients with a FOLR1 gene defect, our patient presented with an abnormal l-dopa metabolism in CSF and high 3-O-methyl-dopa. Upon oral treatment with folinic acid the boy regained consciousness while the epilepsy could be successfully managed only with additional pyridoxal 5'-phosphate (PLP). This report pinpoints the importance of CSF folate investigations in children with unexplained progressive neurological presentations, even if a malformative syndrome is obviously present, and suggests a trial with PLP in folinic acid-unresponsive seizures.
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Affiliation(s)
- Patricia Dill
- Division of Pediatric Neurology and Developmental Medicine, University Children's Hospital, Basel, Switzerland.
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