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Carter MT, Srour M, Au PYB, Buhas D, Dyack S, Eaton A, Inbar-Feigenberg M, Howley H, Kawamura A, Lewis SME, McCready E, Nelson TN, Vallance H. Genetic and metabolic investigations for neurodevelopmental disorders: position statement of the Canadian College of Medical Geneticists (CCMG). J Med Genet 2023; 60:523-532. [PMID: 36822643 DOI: 10.1136/jmg-2022-108962] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 01/27/2023] [Indexed: 02/25/2023]
Abstract
PURPOSE AND SCOPE The aim of this position statement is to provide recommendations for clinicians regarding the use of genetic and metabolic investigations for patients with neurodevelopmental disorders (NDDs), specifically, patients with global developmental delay (GDD), intellectual disability (ID) and/or autism spectrum disorder (ASD). This document also provides guidance for primary care and non-genetics specialists caring for these patients while awaiting consultation with a clinical geneticist or metabolic specialist. METHODS OF STATEMENT DEVELOPMENT A multidisciplinary group reviewed existing literature and guidelines on the use of genetic and metabolic investigations for the diagnosis of NDDs and synthesised the evidence to make recommendations relevant to the Canadian context. The statement was circulated for comment to the Canadian College of Medical Geneticists (CCMG) membership-at-large and to the Canadian Pediatric Society (Mental Health and Developmental Disabilities Committee); following incorporation of feedback, it was approved by the CCMG Board of Directors on 1 September 2022. RESULTS AND CONCLUSIONS Chromosomal microarray is recommended as a first-tier test for patients with GDD, ID or ASD. Fragile X testing should also be done as a first-tier test when there are suggestive clinical features or family history. Metabolic investigations should be done if there are clinical features suggestive of an inherited metabolic disease, while the patient awaits consultation with a metabolic physician. Exome sequencing or a comprehensive gene panel is recommended as a second-tier test for patients with GDD or ID. Genetic testing is not recommended for patients with NDDs in the absence of GDD, ID or ASD, unless accompanied by clinical features suggestive of a syndromic aetiology or inherited metabolic disease.
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Affiliation(s)
| | - Myriam Srour
- Division of Neurology, McGill University Health Centre, Montreal, Québec, Canada
- Department of Pediatrics, McGill University, Montréal, QC, Canada
| | - Ping-Yee Billie Au
- Department of Medical Genetics, Alberta Children's Hospital, Calgary, Alberta, Canada
| | - Daniela Buhas
- Division of Medical Genetics, Department of Specialized Medicine, McGill University Health Centre, McGill University, Montreal, Québec, Canada
- Department of Human Genetics, McGill University, Montreal, QC, Canada
| | - Sarah Dyack
- Division of Medical Genetics, IWK Health Centre, Halifax, Nova Scotia, Canada
- Department of Pediatrics, Dalhousie University, Halifax, NS, Canada
| | - Alison Eaton
- Department of Medical Genetics, Stollery Children's Hospital, Edmonton, Alberta, Canada
- Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada
| | - Michal Inbar-Feigenberg
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Heather Howley
- Office of Research Services, CHEO Research Institute, Ottawa, Ontario, Canada
| | - Anne Kawamura
- Division of Developmental Pediatrics, Holland Bloorview Kids Rehabilitation Hospital, Toronto, Ontario, Canada
- Department of Paediatrics, University of Toronto, Toronto, ON, Canada
- Mental Health and Developmental Disability Committee, Canadian Pediatric Society, Ottawa, ON, Canada
- Canadian Paediatric Society, Toronto, Ontario, Canada
| | - Suzanne M E Lewis
- Department of Medical Genetics, BC Children's and Women's Hospital, Vancouver, British Columbia, Canada
| | - Elizabeth McCready
- Department of Pathology and Molecular Medicine, McMaster University, McMaster University, Hamilton, ON, Canada, Hamilton, Ontario, Canada
- Hamilton Regional Laboratory Medicine Program, Hamilton Health Sciences Centre, Hamilton, ON, Canada
| | - Tanya N Nelson
- Department of Pathology and Laboratory Medicine, BC Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - Hilary Vallance
- Department of Pathology and Laboratory Medicine, BC Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
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Evaluation of Individuals with Non-Syndromic Global Developmental Delay and Intellectual Disability. CHILDREN 2023; 10:children10030414. [PMID: 36979972 PMCID: PMC10047567 DOI: 10.3390/children10030414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 02/11/2023] [Accepted: 02/16/2023] [Indexed: 02/24/2023]
Abstract
Global Developmental Delay (GDD) and Intellectual Disability (ID) are two of the most common presentations encountered by physicians taking care of children. GDD/ID is classified into non-syndromic GDD/ID, where GDD/ID is the sole evident clinical feature, or syndromic GDD/ID, where there are additional clinical features or co-morbidities present. Careful evaluation of children with GDD and ID, starting with detailed history followed by a thorough examination, remain the cornerstone for etiologic diagnosis. However, when initial history and examination fail to identify a probable underlying etiology, further genetic testing is warranted. In recent years, genetic testing has been shown to be the single most important diagnostic modality for clinicians evaluating children with non-syndromic GDD/ID. In this review, we discuss different genetic testing currently available, review common underlying copy-number variants and molecular pathways, explore the recent evidence and recommendations for genetic evaluation and discuss an approach to the diagnosis and management of children with non-syndromic GDD and ID.
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Sachdev R, Field M, Baynam GS, Beilby J, Berarducci M, Berman Y, Boughtwood T, Cusack MB, Fitzgerald V, Fletcher J, Freckmann M, Grainger N, Kirk E, Lundie B, Lunke S, McGregor L, Mowat D, Parasivam G, Tyrell V, Wallis M, White SM, S L Ma A. Paediatric genomic testing: Navigating medicare rebatable genomic testing. J Paediatr Child Health 2021; 57:477-483. [PMID: 33566436 PMCID: PMC8049061 DOI: 10.1111/jpc.15382] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 01/24/2021] [Indexed: 11/30/2022]
Abstract
Genomic testing for a genetic diagnosis is becoming standard of care for many children, especially those with a syndromal intellectual disability. While previously this type of specialised testing was performed mainly by clinical genetics teams, it is increasingly being 'mainstreamed' into standard paediatric care. With the introduction of a new Medicare rebate for genomic testing in May 2020, this type of testing is now available for paediatricians to order, in consultation with clinical genetics. Children must be aged less than 10 years with facial dysmorphism and multiple congenital abnormalities or have global developmental delay or moderate to severe intellectual disability. This rebate should increase the likelihood of a genetic diagnosis, with accompanying benefits for patient management, reproductive planning and diagnostic certainty. Similar to the introduction of chromosomal microarray into mainstream paediatrics, this genomic testing will increase the number of genetic diagnoses, however, will also yield more variants of uncertain significance, incidental findings, and negative results. This paper aims to guide paediatricians through the process of genomic testing, and represents the combined expertise of educators, clinical geneticists, paediatricians and genomic pathologists around Australia. Its purpose is to help paediatricians navigate choosing the right genomic test, consenting patients and understanding the possible outcomes of testing.
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Affiliation(s)
- Rani Sachdev
- Centre for Clinical Genetics, Sydney Children's Hospital‐RandwickSydney Children's Hospitals NetworkSydneyNew South WalesAustralia,School of Women's and Children's HealthUniversity of New South WalesSydneyNew South WalesAustralia
| | - Mike Field
- Cancer GeneticsRoyal North Shore HospitalSydneyNew South WalesAustralia,GOLD ServiceHunter‐New England Health ServiceNewcastleNew South WalesAustralia
| | - Gareth S Baynam
- Department of HealthGenetic Services of Western AustraliaPerthWestern AustraliaAustralia
| | - John Beilby
- Department of Diagnostic GenomicsPathWest Laboratory MedicinePerthWestern AustraliaAustralia
| | - Maria Berarducci
- Health Education and Training Institute (HETI)NSW Health ServiceSydneyNew South WalesAustralia
| | - Yemima Berman
- Department of Clinical GeneticsRoyal North Shore HospitalSydneyNew South WalesAustralia,Sydney Medical SchoolUniversity of SydneySydneyNew South WalesAustralia
| | - Tiffany Boughtwood
- Australian GenomicsParkvilleVictoriaAustralia,Murdoch Children's Research InstituteParkvilleVictoriaAustralia
| | - Marie B Cusack
- NSW Health Centre for Genetics EducationRoyal North Shore HospitalSydneyNew South WalesAustralia
| | - Vanessa Fitzgerald
- Speciality Services and Technology Evaluation Unit, Strategic Reform and Planning BranchNSW Ministry of HealthSydneyNew South WalesAustralia
| | - Jeffery Fletcher
- Department of PaediatricsThe Tweed HospitalTweed HeadsNew South WalesAustralia
| | - Mary‐Louise Freckmann
- Department of Clinical GeneticsRoyal North Shore HospitalSydneyNew South WalesAustralia
| | - Natalie Grainger
- NSW Health Centre for Genetics EducationRoyal North Shore HospitalSydneyNew South WalesAustralia
| | - Edwin Kirk
- Centre for Clinical Genetics, Sydney Children's Hospital‐RandwickSydney Children's Hospitals NetworkSydneyNew South WalesAustralia,School of Women's and Children's HealthUniversity of New South WalesSydneyNew South WalesAustralia,Randwick Genomics LaboratoryNSW Health PathologySydneyNew South WalesAustralia
| | - Ben Lundie
- Pathology QueenslandRoyal Brisbane and Women's HospitalBrisbaneQueenslandAustralia
| | - Sebastian Lunke
- Victorian Clinical Genetics ServicesMurdoch Children's Research InstituteMelbourneVictoriaAustralia,Department of PathologyUniversity of MelbourneMelbourneVictoriaAustralia
| | - Lesley McGregor
- South Australian Clinical Genetics ServiceWomen's and Children's HospitalAdelaideSouth AustraliaAustralia
| | - David Mowat
- Centre for Clinical Genetics, Sydney Children's Hospital‐RandwickSydney Children's Hospitals NetworkSydneyNew South WalesAustralia,School of Women's and Children's HealthUniversity of New South WalesSydneyNew South WalesAustralia
| | - Gayathri Parasivam
- NSW Health Centre for Genetics EducationRoyal North Shore HospitalSydneyNew South WalesAustralia
| | - Vanessa Tyrell
- Children's Cancer Institute. RandwickSydneyNew South WalesAustralia
| | - Mathew Wallis
- Tasmanian Clinical Genetics Service, Tasmanian Health ServiceRoyal Hobart HospitalHobartTasmaniaAustralia,School of MedicineThe University of TasmaniaHobartTasmaniaAustralia
| | - Susan M White
- Victorian Clinical Genetics ServicesMurdoch Children's Research InstituteMelbourneVictoriaAustralia,Department of PaediatricsUniversity of MelbourneMelbourneVictoriaAustralia
| | - Alan S L Ma
- Specialty of Genomic MedicineUniversity of SydneySydneyNew South WalesAustralia,Department of Clinical Genetics, Children's Hospital WestmeadSydney Children's Hospitals NetworkSydneyNew South WalesAustralia
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The diagnosis of inborn errors of metabolism in previously undiagnosed adults referred for medical genetics evaluation. Mol Genet Metab Rep 2020; 25:100653. [PMID: 33072517 PMCID: PMC7549142 DOI: 10.1016/j.ymgmr.2020.100653] [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: 08/13/2020] [Revised: 09/15/2020] [Accepted: 09/19/2020] [Indexed: 11/21/2022] Open
Abstract
Traditionally thought of as a pediatric diagnostic and therapeutic dilemma, the diagnostic rate and spectrum of inborn errors of metabolism (IEM) in the adult population is largely unknown. A retrospective chart review of patients seen by the Michigan Medicine Adult Medical Genetics Clinic for clinical evaluation from 2014 to 2018 was conducted. Patients referred for a primary indication possibly consistent with an IEM were considered. Variables included age at genetic evaluation, symptom onset age, sex, clinical course, organ systems involved, developmental history, family history and prior genetic testing. Of patients evaluated during the study period, 112 were referred for an indication possibly consistent with an IEM and underwent a complete biochemical workup with an IEM diagnostic rate of 9.8% achieved. An additional 9.8% were diagnosed with a non-IEM genetic diagnosis. Management changes were implemented in all IEM diagnoses. Metabolic disorders in the adult population are under-recognized and under-diagnosed. This report demonstrates the need for clinicians to consider these diagnoses in adults and either refer to a genetics clinic or initiate a biochemical workup. As advances in diagnosis, treatment, and life expectancy of patients with IEMs increases, recognizing and diagnosing these conditions can significantly impact care.
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Kubaski F, de Oliveira Poswar F, Michelin-Tirelli K, Burin MG, Rojas-Málaga D, Brusius-Facchin AC, Leistner-Segal S, Giugliani R. Diagnosis of Mucopolysaccharidoses. Diagnostics (Basel) 2020; 10:E172. [PMID: 32235807 PMCID: PMC7151013 DOI: 10.3390/diagnostics10030172] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 03/16/2020] [Accepted: 03/18/2020] [Indexed: 12/13/2022] Open
Abstract
The mucopolysaccharidoses (MPSs) include 11 different conditions caused by specific enzyme deficiencies in the degradation pathway of glycosaminoglycans (GAGs). Although most MPS types present increased levels of GAGs in tissues, including blood and urine, diagnosis is challenging as specific enzyme assays are needed for the correct diagnosis. Enzyme assays are usually performed in blood, with some samples (as leukocytes) providing a final diagnosis, while others (such as dried blood spots) still being considered as screening methods. The identification of variants in the specific genes that encode each MPS-related enzyme is helpful for diagnosis confirmation (when needed), carrier detection, genetic counseling, prenatal diagnosis (preferably in combination with enzyme assays) and phenotype prediction. Although the usual diagnostic flow in high-risk patients starts with the measurement of urinary GAGs, it continues with specific enzyme assays and is completed with mutation identification; there is a growing trend to have genotype-based investigations performed at the beginning of the investigation. In such cases, confirmation of pathogenicity of the variants identified should be confirmed by measurement of enzyme activity and/or identification and/or quantification of GAG species. As there is a growing number of countries performing newborn screening for MPS diseases, the investigation of a low enzyme activity by the measurement of GAG species concentration and identification of gene mutations in the same DBS sample is recommended before the suspicion of MPS is taken to the family. With specific therapies already available for most MPS patients, and with clinical trials in progress for many conditions, the specific diagnosis of MPS as early as possible is becoming increasingly necessary. In this review, we describe traditional and the most up to date diagnostic methods for mucopolysaccharidoses.
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Affiliation(s)
- Francyne Kubaski
- Postgraduate Program in Genetics and Molecular Biology, UFRGS, Porto Alegre 91501-970, Brazil; (F.K.); (F.d.O.P.); (D.R.-M.)
- Medical Genetics Service, HCPA, Porto Alegre 90035-903, Brazil; (K.M.-T.); (M.G.B.); (A.C.B.-F.); (S.L.-S.)
- INAGEMP, Porto Alegre 90035-903, Brazil
- Biodiscovery Research Group, Experimental Research Center, HCPA, Porto Alegre 90035-903, Brazil
| | - Fabiano de Oliveira Poswar
- Postgraduate Program in Genetics and Molecular Biology, UFRGS, Porto Alegre 91501-970, Brazil; (F.K.); (F.d.O.P.); (D.R.-M.)
- Medical Genetics Service, HCPA, Porto Alegre 90035-903, Brazil; (K.M.-T.); (M.G.B.); (A.C.B.-F.); (S.L.-S.)
| | - Kristiane Michelin-Tirelli
- Medical Genetics Service, HCPA, Porto Alegre 90035-903, Brazil; (K.M.-T.); (M.G.B.); (A.C.B.-F.); (S.L.-S.)
- Biodiscovery Research Group, Experimental Research Center, HCPA, Porto Alegre 90035-903, Brazil
| | - Maira Graeff Burin
- Medical Genetics Service, HCPA, Porto Alegre 90035-903, Brazil; (K.M.-T.); (M.G.B.); (A.C.B.-F.); (S.L.-S.)
- Biodiscovery Research Group, Experimental Research Center, HCPA, Porto Alegre 90035-903, Brazil
| | - Diana Rojas-Málaga
- Postgraduate Program in Genetics and Molecular Biology, UFRGS, Porto Alegre 91501-970, Brazil; (F.K.); (F.d.O.P.); (D.R.-M.)
- Medical Genetics Service, HCPA, Porto Alegre 90035-903, Brazil; (K.M.-T.); (M.G.B.); (A.C.B.-F.); (S.L.-S.)
| | - Ana Carolina Brusius-Facchin
- Medical Genetics Service, HCPA, Porto Alegre 90035-903, Brazil; (K.M.-T.); (M.G.B.); (A.C.B.-F.); (S.L.-S.)
- INAGEMP, Porto Alegre 90035-903, Brazil
- Biodiscovery Research Group, Experimental Research Center, HCPA, Porto Alegre 90035-903, Brazil
- Postgraduate Program in Medicine, Clinical Sciences, UFRGS, Porto Alegre 90035-003, Brazil
| | - Sandra Leistner-Segal
- Medical Genetics Service, HCPA, Porto Alegre 90035-903, Brazil; (K.M.-T.); (M.G.B.); (A.C.B.-F.); (S.L.-S.)
- INAGEMP, Porto Alegre 90035-903, Brazil
- Biodiscovery Research Group, Experimental Research Center, HCPA, Porto Alegre 90035-903, Brazil
- Postgraduate Program in Medicine, Clinical Sciences, UFRGS, Porto Alegre 90035-003, Brazil
| | - Roberto Giugliani
- Postgraduate Program in Genetics and Molecular Biology, UFRGS, Porto Alegre 91501-970, Brazil; (F.K.); (F.d.O.P.); (D.R.-M.)
- Medical Genetics Service, HCPA, Porto Alegre 90035-903, Brazil; (K.M.-T.); (M.G.B.); (A.C.B.-F.); (S.L.-S.)
- INAGEMP, Porto Alegre 90035-903, Brazil
- Biodiscovery Research Group, Experimental Research Center, HCPA, Porto Alegre 90035-903, Brazil
- Postgraduate Program in Medicine, Clinical Sciences, UFRGS, Porto Alegre 90035-003, Brazil
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Malaguarnera M, Cauli O. Effects of l-Carnitine in Patients with Autism Spectrum Disorders: Review of Clinical Studies. Molecules 2019; 24:molecules24234262. [PMID: 31766743 PMCID: PMC6930613 DOI: 10.3390/molecules24234262] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 11/21/2019] [Accepted: 11/21/2019] [Indexed: 12/27/2022] Open
Abstract
Carnitine is an amino acid derivative, which plays several important roles in human physiology, in the central nervous system, and for mitochondrial metabolism, in particular. Altered carnitine metabolic routes have been associated with a subgroup of patients with autism spectrum disorders (ASD) and could add to the pathophysiology associated with these disorders. We review the current evidence about the clinical effects of carnitine administration in ASD in both non-syndromic forms and ASD associated with genetic disorders. Two randomized clinical trials and one open-label prospective trial suggest that carnitine administration could be useful for treating symptoms in non-syndromic ASD. The effect of carnitine administration in ASD associated with genetic disorders is not conclusive because of a lack of clinical trials and objectives in ASD evaluation, but beneficial effects have also been reported for other comorbid disorders, such as intellectual disability and muscular strength. Side effects observed with a dose of 200 mg/kg/day consisted of gastro-intestinal symptoms and a strong, heavy skin odor. Doses of about 50–100 mg/kg/day are generally well tolerated. Further clinical trials with the identification of the subgroup of ASD patients that would benefit from carnitine administration are warranted.
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Affiliation(s)
- Michele Malaguarnera
- Research Center “The Great Senescence”, University of Catania, 95100 Catania, Italy;
- Department of Nursing, University of Valencia, 46010 Valencia, Spain
| | - Omar Cauli
- Department of Nursing, University of Valencia, 46010 Valencia, Spain
- Frailty and Cognitive Impairment Group (FROG), University of Valencia, 46010 Valencia, Spain
- Correspondence:
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Inducible Slc7a7 Knockout Mouse Model Recapitulates Lysinuric Protein Intolerance Disease. Int J Mol Sci 2019; 20:ijms20215294. [PMID: 31653080 PMCID: PMC6862226 DOI: 10.3390/ijms20215294] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 10/21/2019] [Accepted: 10/22/2019] [Indexed: 12/30/2022] Open
Abstract
Lysinuric protein intolerance (LPI) is a rare autosomal disease caused by defective cationic amino acid (CAA) transport due to mutations in SLC7A7, which encodes for the y+LAT1 transporter. LPI patients suffer from a wide variety of symptoms, which range from failure to thrive, hyperammonemia, and nephropathy to pulmonar alveolar proteinosis (PAP), a potentially life-threatening complication. Hyperammonemia is currently prevented by citrulline supplementation. However, the full impact of this treatment is not completely understood. In contrast, there is no defined therapy for the multiple reported complications of LPI, including PAP, for which bronchoalveolar lavages do not prevent progression of the disease. The lack of a viable LPI model prompted us to generate a tamoxifen-inducible Slc7a7 knockout mouse (Slc7a7-/-). The Slc7a7-/- model resembles the human LPI phenotype, including malabsorption and impaired reabsorption of CAA, hypoargininemia and hyperammonemia. Interestingly, the Slc7a7-/- mice also develops PAP and neurological impairment. We observed that citrulline treatment improves the metabolic derangement and survival. On the basis of our findings, the Slc7a7-/- model emerges as a promising tool to further study the complexity of LPI, including its immune-like complications, and to design evidence-based therapies to halt its progression.
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Campistol J, Díez-Juan M, Callejón L, Fernandez-De Miguel A, Casado M, Garcia Cazorla A, Lozano R, Artuch R. Inborn error metabolic screening in individuals with nonsyndromic autism spectrum disorders. Dev Med Child Neurol 2016; 58:842-7. [PMID: 27038397 DOI: 10.1111/dmcn.13114] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/05/2016] [Indexed: 12/14/2022]
Abstract
AIM To perform metabolic testing on 406 patients (age range 3-22y [mean 6.71, SD 4.15], 343 males and 63 females) with nonsyndromic autism spectrum disorders (ASD) to assess the diagnostic yield. In addition, we reviewed our hospital's clinical database of 8500 patients who had undergone metabolic testing to be identified for inborn errors of metabolism (IEM), and described the characteristics of those with IEM and nonsyndromic ASD. METHOD Neuropsychological evaluation included the Social Communication Questionnaire and Child Behavior Checklist. For metabolic testing/screening, urine samples were analyzed for the diagnosis of cerebral creatine deficiency syndromes, purine and pyrimidine disorders, amino acid metabolism defects, mucopolysaccharidoses, and organic acidurias. RESULTS The 406 recruited participants fulfilled the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) criteria of ASD. No biochemical evidence of a metabolic disorder was detected in any of the 406 patients studied. Concerning the retrospective evaluation from the 8500 who had metabolic testing, 464 individuals had a diagnosis of an IEM (394 without the diagnosis of ASD and 70 with ASD diagnosis). Only one individual with IEM had a diagnosis of nonsyndromic ASD at the time of the metabolic study; the metabolic testing had revealed diagnosis of urea-cycle disorder. INTERPRETATION Metabolic testing should be considered in the work-up of individuals with syndromic ASD, but metabolic testing is not cost-effective for individuals with nonsyndromic ASD.
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Affiliation(s)
- Jaume Campistol
- Pediatric Neurology and Clinical Biochemistry Departments, Institut de Recerca Pediátrica, Hospital Sant Joan de Déu and CIBERER-ISCIII, Barcelona, Spain
| | - María Díez-Juan
- Unidad Especializada en Trastornos del Desarrollo, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Laura Callejón
- Unidad Especializada en Trastornos del Desarrollo, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Aroa Fernandez-De Miguel
- Pediatric Neurology and Clinical Biochemistry Departments, Institut de Recerca Pediátrica, Hospital Sant Joan de Déu and CIBERER-ISCIII, Barcelona, Spain
| | - Mercedes Casado
- Pediatric Neurology and Clinical Biochemistry Departments, Institut de Recerca Pediátrica, Hospital Sant Joan de Déu and CIBERER-ISCIII, Barcelona, Spain
| | - Angels Garcia Cazorla
- Pediatric Neurology and Clinical Biochemistry Departments, Institut de Recerca Pediátrica, Hospital Sant Joan de Déu and CIBERER-ISCIII, Barcelona, Spain
| | - Reymundo Lozano
- Seaver Autism Center for Research and Treatment, Departments of Genetics and Genomic Sciences, Psychiatry, and Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Rafael Artuch
- Pediatric Neurology and Clinical Biochemistry Departments, Institut de Recerca Pediátrica, Hospital Sant Joan de Déu and CIBERER-ISCIII, Barcelona, Spain
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Hope S, Johannessen CH, Aanonsen NO, Strømme P. The investigation of inborn errors of metabolism as an underlying cause of idiopathic intellectual disability in adults in Norway. Eur J Neurol 2015; 23 Suppl 1:36-44. [DOI: 10.1111/ene.12884] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/25/2015] [Indexed: 12/17/2022]
Affiliation(s)
- S. Hope
- Department of Neuro Habilitation; Oslo University Hospital, Ullevål; Oslo Norway
- NORMENT; KG Jebsen Centre for Psychosis Research; Institute of Clinical Medicine; University of Oslo; Oslo Norway
| | - C. H. Johannessen
- Department of Neuro Habilitation; Oslo University Hospital, Ullevål; Oslo Norway
| | - N. O. Aanonsen
- Department of Neuro Habilitation; Oslo University Hospital, Ullevål; Oslo Norway
| | - P. Strømme
- Department of Clinical Neurosciences for Children; Women and Children′s Division; Oslo University Hospital, Ullevål; Oslo Norway
- University of Oslo; Oslo Norway
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Eun SH, Hahn SH. Metabolic evaluation of children with global developmental delay. KOREAN JOURNAL OF PEDIATRICS 2015; 58:117-22. [PMID: 25932032 PMCID: PMC4414625 DOI: 10.3345/kjp.2015.58.4.117] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 03/04/2015] [Indexed: 12/05/2022]
Abstract
Global developmental delay (GDD) is a relatively common early-onset chronic neurological condition, which may have prenatal, perinatal, postnatal, or undetermined causes. Family history, physical and neurological examinations, and detailed history of environmental risk factors might suggest a specific disease. However, diagnostic laboratory tests, brain imaging, and other evidence-based evaluations are necessary in most cases to elucidate the causes. Diagnosis of GDD has recently improved because of remarkable advances in genetic technology, but this is an exhaustive and expensive evaluation that may not lead to therapeutic benefits in the majority of GDD patients. Inborn metabolic errors are one of the main targets for the treatment of GDD, although only a small proportion of GDD patients have this type of error. Nevertheless, diagnosis is often challenging because the phenotypes of many genetic or metabolic diseases often overlap, and their clinical spectra are much broader than currently known. Appropriate and cost-effective strategies including up-to-date information for the early identification of the "treatable" causes of GDD are needed for the development of well-timed therapeutic applications with the potential to improve neurodevelopmental outcomes.
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Affiliation(s)
- So-Hee Eun
- Department of Pediatrics, Korea University College of Medicine, Seoul, Korea
| | - Si Houn Hahn
- Division of Genetic Medicine, Department of Pediatrics, University of Washington School of Medicine, Seattle, WA, USA
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van Karnebeek CDM, Shevell M, Zschocke J, Moeschler JB, Stockler S. The metabolic evaluation of the child with an intellectual developmental disorder: diagnostic algorithm for identification of treatable causes and new digital resource. Mol Genet Metab 2014; 111:428-38. [PMID: 24518794 DOI: 10.1016/j.ymgme.2014.01.011] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 01/19/2014] [Accepted: 01/19/2014] [Indexed: 11/23/2022]
Abstract
Intellectual developmental disorders (IDD), characterized by significant impairment of cognitive functions, with limitations of learning, adaptive behavior and skills, are frequent (2.5% of the population affected) and present with significant co-morbidity. The burden of IDD, in terms of emotional suffering and associated health care costs, is significant; prevention and treatment therefore are important. A systematic literature review, updated in 2013, identified 89 inborn errors of metabolism (IEMs), which present with IDD as prominent feature and are amenable to causal therapy. Therapeutic effects include improvement and/or stabilization of psychomotor/cognitive development, behavior/psychiatric disturbances, seizures, neurologic and systemic manifestations. The levels of available evidence for the various treatments range from Level 1b, c (n=5); Level 2a, b, c (n=14); Level 4 (n=53), and Levels 4-5 (n=27). For a target audience comprising clinical and biochemical geneticists, child neurologists and developmental pediatricians, five experts translated....this data into a 2-tiered diagnostic algorithm: The first tier comprises metabolic "screening" tests in urine and blood, which are relatively accessible, affordable, less invasive, and have the potential to identify 60% of all treatable IEMs. The second tier investigations for the remaining disorders are ordered based on individual clinical signs and symptoms. This algorithm is supported by an App www.treatable-id.org, which comprises up-to-date information on all 89 IEMs, relevant diagnostic tests, therapies and a search function based on signs and symptoms. These recommendations support the clinician in early identification of treatable IEMs in the child with IDD, allowing for timely initiation of therapy with the potential to improve neurodevelopmental outcomes. The need for future studies to determine yield and usefulness of these recommendations, with subsequent updates and improvements to developments in the field, is outlined.
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Affiliation(s)
- Clara D M van Karnebeek
- Division of Biochemical Diseases, Department of Pediatrics, BC Children's Hospital, Child & Family Research Institute, University of British Columbia, Vancouver, Canada; Treatable Intellectual Disability Endeavor in British Columbia (TIDE-BC (TIDE-BC, www.tidebc.org)), Canada.
| | - Michael Shevell
- Department of Pediatrics, Montreal Children's Hospital, McGill University, Montreal, Canada; Department of Neurology/Neurosurgery, Montreal Children's Hospital, McGill University, Montreal, Canada
| | - Johannes Zschocke
- Division of Human Genetics, Medical University of Innsbruck, Innsbruck, Austria
| | - John B Moeschler
- Geisel School of Medicine at Dartmouth College, Lebanon, NH, USA
| | - Sylvia Stockler
- Division of Biochemical Diseases, Department of Pediatrics, BC Children's Hospital, Child & Family Research Institute, University of British Columbia, Vancouver, Canada; Treatable Intellectual Disability Endeavor in British Columbia (TIDE-BC (TIDE-BC, www.tidebc.org)), Canada
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12
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Spilioti M, Evangeliou AE, Tramma D, Theodoridou Z, Metaxas S, Michailidi E, Bonti E, Frysira H, Haidopoulou A, Asprangathou D, Tsalkidis AJ, Kardaras P, Wevers RA, Jakobs C, Gibson KM. Evidence for treatable inborn errors of metabolism in a cohort of 187 Greek patients with autism spectrum disorder (ASD). Front Hum Neurosci 2013; 7:858. [PMID: 24399946 PMCID: PMC3871708 DOI: 10.3389/fnhum.2013.00858] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Accepted: 11/25/2013] [Indexed: 12/27/2022] Open
Abstract
We screened for the presence of inborn errors of metabolism (IEM) in 187 children (105 males; 82 females, ages 4–14 years old) who presented with confirmed features of autism spectrum disorder (ASD). Twelve patients (7%) manifested increased 3-hydroxyisovaleric acid (3-OH-IVA) excretion in urine, and minor to significant improvement in autistic features was observed in seven patients following supplementation with biotin. Five diagnoses included: Lesch Nyhan syndrome (2), succinic semialdehyde dehydrogenase (SSADH) deficiency (2), and phenylketonuria (1) (2.7%). Additional metabolic disturbances suggestive of IEMs included two patients whose increased urine 3-OH-IVA was accompanied by elevated methylcitrate and lactate in sera, and 30 patients that showed abnormal glucose-loading tests. In the latter group, 16/30 patients manifested increased sera beta hydroxybutyrate (b-OH-b) production and 18/30 had a paradoxical increase of sera lactate. Six patients with elevated b-OH-b in sera showed improved autistic features following implementation of a ketogenic diet (KD). Five patients showed decreased serum ketone body production with glucose loading. Twelve of 187 patients demonstrated non-specific MRI pathology, while 25/187 had abnormal electroencephalogram (EEG) findings. Finally, family history was positive for 22/187 patients (1st or 2nd degree relative with comparable symptomatology) and consanguinity was documented for 12/187 patients. Our data provide evidence for a new biomarker (3-OH-IVA) and novel treatment approaches in ASD patients. Concise 1 sentence take-home message: Detailed metabolic screening in a Greek cohort of ASD patients revealed biomarkers (urine 3-hydroxyisovaleric acid and serum b-OH-b) in 7% (13/187) of patients for whom biotin supplementation or institution of a KD resulted in mild to significant clinical improvement in autistic features.
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Affiliation(s)
- Martha Spilioti
- First Department of Neurology, AHEPA Hospital, Aristotle University of Thessaloniki Thessaloniki, Greece
| | - Athanasios E Evangeliou
- Fourth Department of Pediatrics, Papageorgiou Hospital, Aristotle University of Thessaloniki Thessaloniki, Greece
| | - Despoina Tramma
- Fourth Department of Pediatrics, Papageorgiou Hospital, Aristotle University of Thessaloniki Thessaloniki, Greece
| | - Zoe Theodoridou
- Department of Special Educational Needs, St. Luke's Hospital Thessaloniki, Greece
| | - Spyridon Metaxas
- Second ENT Department, Papageorgiou Hospital, Aristotle University of Thessaloniki Thessaloniki, Greece
| | - Eleni Michailidi
- Department of Pediatrics, Medical School, University of Crete Heraklion, Greece
| | - Eleni Bonti
- Department of Pediatrics, Papageorgiou Hospital, Aristotle University of Thessaloniki Thessaloniki, Greece
| | - Helen Frysira
- Department of Pediatrics, Athens University Medical School, Agia Sophia Children's Hospital Athens, Greece
| | - A Haidopoulou
- Fourth Department of Pediatrics, Papageorgiou Hospital, Aristotle University of Thessaloniki Thessaloniki, Greece
| | - Despoina Asprangathou
- Fourth Department of Pediatrics, Papageorgiou Hospital, Aristotle University of Thessaloniki Thessaloniki, Greece
| | - Aggelos J Tsalkidis
- Department of Pediatrics, Medical School, University of Thrace Alexandroupolis, Greece
| | - Panagiotis Kardaras
- Third Department of Pediatrics, Hippokration Hospital, Aristotle University of Thessaloniki Thessaloniki, Greece
| | - Ron A Wevers
- Laboratory of Genetic, Endocrine and Metabolic Diseases, Department of Laboratory Medicine, RUNMC Nijmegen, Netherlands
| | - Cornelis Jakobs
- Metabolic Unit, Department of Clinical Chemistry, VU University Medical Center Amsterdam, Netherlands
| | - K Michael Gibson
- Section of Clinical Pharmacology, College of Pharmacy, Washington State University Spokane, WA, USA
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13
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Hagedorn TS, van Berkel P, Hammerschmidt G, Lhotáková M, Saludes RP. Requirements for a minimum standard of care for phenylketonuria: the patients' perspective. Orphanet J Rare Dis 2013; 8:191. [PMID: 24341788 PMCID: PMC3878574 DOI: 10.1186/1750-1172-8-191] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Accepted: 11/12/2013] [Indexed: 11/22/2022] Open
Abstract
Phenylketonuria (PKU, ORPHA716) is an inherited disorder that affects about one in every 10,000 children born in Europe. Early and continuous application of a modified diet is largely successful in preventing the devastating brain damage associated with untreated PKU. The management of PKU is inconsistent: there are few national guidelines, and these tend to be incomplete and implemented sporadically. In this article, the first-ever pan- European patient/carer perspective on optimal PKU care, the European Society for Phenylketonuria and Allied Disorders (E.S.PKU) proposes recommendations for a minimum standard of care for PKU, to underpin the development of new pan-European guideline for the management of PKU. New standards of best practice should guarantee equal access to screening, treatment and monitoring throughout Europe. Screening protocols and interpretation of screening results should be standardised. Experienced Centres of Expertise are required, in line with current European Union policy, to guarantee a defined standard of multidisciplinary treatment and care for all medical and social aspects of PKU. Women of childbearing age require especially intensive management, due to the risk of severe risks to the foetus conferred by uncontrolled PKU. All aspects of treatment should be reimbursed to ensure uniform access across Europe to guideline-driven, evidence-based care. The E.S.PKU urges PKU healthcare professionals caring for people with PKU to take the lead in developing evidence based guidelines on PKU, while continuing to play an active role in serving as the voice of patients and their families, whose lives are affected by the condition.
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Affiliation(s)
- Tobias S Hagedorn
- European Society for Phenylketonuria and Allied Disorders (E,S,PKU), Melsele, Belgium.
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14
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Ibarra-González I, Fernández-Lainez C, Belmont-Martínez L, Guillén-López S, Monroy-Santoyo S, Vela-Amieva M. [Characterization of inborn errors of intermediary metabolism in mexican patients]. An Pediatr (Barc) 2013; 80:310-6. [PMID: 24140120 DOI: 10.1016/j.anpedi.2013.09.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Revised: 06/04/2013] [Accepted: 09/04/2013] [Indexed: 01/24/2023] Open
Abstract
INTRODUCTION Inborn errors of intermediary metabolism (IEiM) are a group of heterogeneous genetic diseases that are diagnostically challenging and cause significant morbidity and mortality. The aim of this study is to perform a descriptive analysis of the number, type, and clinical features, in a series of cases with IEiM identified through selective diagnosis in a highly specialized pediatric hospital. MATERIALS AND METHODS A retrospective study was performed from January of 2000 to December of 2012 by analyzing the files of 204 patients with an IEiM, by selective screening, before and after the implementation of tandem mass spectrometry (MS/MS). RESULTS A total of 25 different types of IEiM were found in the 204 files; 102 organic acidurias, 100 aminoacidopathies, and 2 fatty acid oxidation disorders. The introduction of MS/MS increased the number of cases detected by 50%. Patients were referred from 13 different specialists, with pediatricians being the most active. The average interval between onset of symptoms and diagnosis was 18 months. CONCLUSION Among the sick Mexican children studied, a wide variety of IEiM was found, propionate defects and maple syrup urine disease being noteworthy. The diagnosis of metabolic disease was delayed in the population studied. These results present evidence to perhaps incorporate IEiM into an expanded newborn screening, or else to perform selective diagnosis in all hospitalized children with suggestive clinical data.
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Affiliation(s)
- I Ibarra-González
- Unidad de Genética de la Nutrición, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México
| | - C Fernández-Lainez
- Laboratorio de Errores Innatos del Metabolismo y Tamiz, Instituto Nacional de Pediatría, Secretaría de Salud, México
| | - L Belmont-Martínez
- Laboratorio de Errores Innatos del Metabolismo y Tamiz, Instituto Nacional de Pediatría, Secretaría de Salud, México
| | - S Guillén-López
- Laboratorio de Errores Innatos del Metabolismo y Tamiz, Instituto Nacional de Pediatría, Secretaría de Salud, México
| | - S Monroy-Santoyo
- Laboratorio de Errores Innatos del Metabolismo y Tamiz, Instituto Nacional de Pediatría, Secretaría de Salud, México
| | - M Vela-Amieva
- Laboratorio de Errores Innatos del Metabolismo y Tamiz, Instituto Nacional de Pediatría, Secretaría de Salud, México.
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15
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Duval N, Luhrs K, Wilkinson TG, Baresova V, Skopova V, Kmoch S, Vacano GN, Zikanova M, Patterson D. Genetic and metabolomic analysis of AdeD and AdeI mutants of de novo purine biosynthesis: cellular models of de novo purine biosynthesis deficiency disorders. Mol Genet Metab 2013; 108:178-189. [PMID: 23394948 PMCID: PMC4296673 DOI: 10.1016/j.ymgme.2013.01.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Revised: 01/04/2013] [Accepted: 01/05/2013] [Indexed: 02/06/2023]
Abstract
Purines are molecules essential for many cell processes, including RNA and DNA synthesis, regulation of enzyme activity, protein synthesis and function, energy metabolism and transfer, essential coenzyme function, and cell signaling. Purines are produced via the de novo purine biosynthesis pathway. Mutations in purine biosynthetic genes, for example phosphoribosylaminoimidazole carboxylase/phosphoribosylaminoimidazole succinocarboxamide synthetase (PAICS, E.C. 6.3.2.6/E.C. 4.1.1.21), can lead to developmental anomalies in lower vertebrates. Alterations in PAICS expression in humans have been associated with various types of cancer. Mutations in adenylosuccinate lyase (ADSL, E.C. 4.3.2.2) or 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/IMP cyclohydrolase (ATIC, E.C. 2.1.2.3/E.C. 3.5.4.10) lead to inborn errors of metabolism with a range of clinical symptoms, including developmental delay, severe neurological symptoms, and autistic features. The pathogenetic mechanism is unknown for these conditions, and no effective treatments exist. The study of cells carrying mutations in the various de novo purine biosynthesis pathway genes provides one approach to analysis of purine disorders. Here we report the characterization of AdeD Chinese hamster ovary (CHO) cells, which carry genetic mutations encoding p.E177K and p.W363* variants of PAICS. Both mutations impact PAICS structure and completely abolish its biosynthesis. Additionally, we describe a sensitive and rapid analytical method for detection of purine de novo biosynthesis intermediates based on high performance liquid chromatography with electrochemical detection. Using this technique we detected accumulation of AIR in AdeD cells. In AdeI cells, mutant for the ADSL gene, we detected accumulation of SAICAR and SAMP and, somewhat unexpectedly, accumulation of AIR. This method has great potential for metabolite profiling of de novo purine biosynthesis pathway mutants, identification of novel genetic defects of purine metabolism in humans, and elucidating the regulation of this critical metabolic pathway.
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Affiliation(s)
- Nathan Duval
- Eleanor Roosevelt Institute and Department of Biological Sciences, University of Denver, 2101 E. Wesley Ave., Denver, CO 80208, USA
| | - Kyleen Luhrs
- Eleanor Roosevelt Institute and Department of Biological Sciences, University of Denver, 2101 E. Wesley Ave., Denver, CO 80208, USA
| | - Terry G. Wilkinson
- Eleanor Roosevelt Institute and Department of Biological Sciences, University of Denver, 2101 E. Wesley Ave., Denver, CO 80208, USA
| | - Veronika Baresova
- Institute of Inherited Metabolic Disorders, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Ke Karlovu 2, 120 00 Prague 2, Czech Republic
| | - Vaclava Skopova
- Institute of Inherited Metabolic Disorders, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Ke Karlovu 2, 120 00 Prague 2, Czech Republic
| | - Stanislav Kmoch
- Institute of Inherited Metabolic Disorders, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Ke Karlovu 2, 120 00 Prague 2, Czech Republic
| | - Guido N. Vacano
- Eleanor Roosevelt Institute and Department of Biological Sciences, University of Denver, 2101 E. Wesley Ave., Denver, CO 80208, USA
| | - Marie Zikanova
- Institute of Inherited Metabolic Disorders, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Ke Karlovu 2, 120 00 Prague 2, Czech Republic
| | - David Patterson
- Eleanor Roosevelt Institute and Department of Biological Sciences, University of Denver, 2101 E. Wesley Ave., Denver, CO 80208, USA
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16
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Abstract
The lack of creatine in the central nervous system causes a severe but treatable neurological disease. Three inherited defects, AGAT, GAMT, and CrT deficiency, compromising synthesis and transport of creatine have been discovered recently. Together these so-called creatine deficiency syndromes (CDS) might represent the most frequent metabolic disorders with a primarily neurological phenotype. Patients with CDS present with global developmental delays, mental retardation, speech impairment especially affecting active language, seizures, extrapyramidal movement disorder, and autism spectrum disorder. The two defects in the creatine synthesis, AGAT and GAMT, are autosomal recessive disorders. They can be diagnosed by analysis of the creatine, guanidinoacetate, and creatinine in body fluids. Treatment is available and, especially when introduced in infancy, has a good outcome. The defect of creatine transport, CrT, is an X-linked condition and perhaps the most frequent reasons for X-linked mental retardation. Diagnosis is made by an increased ratio of creatine to creatinine in urine, but successful treatment still needs to be explored. CDS are under-diagnosed because easy to miss in standard diagnostic workup. Because CDS represent a frequent cause of cognitive and neurological impairment that is treatable they warrant consideration in the workup for genetic mental retardation syndromes, for intractable seizure disorders, and for neurological diseases with a predominant lack of active speech.
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Affiliation(s)
- Andreas Schulze
- Division of Clinical and Metabolic Genetics, Department of Paediatrics, Research Institute, Hospital for Sick Children and University of Toronto, Toronto, Canada.
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17
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Pérez-Dueñas B, Sempere A, Campistol J, Alonso-Colmenero I, Díez M, González V, Merinero B, Desviat LR, Artuch R. Novel features in the evolution of adenylosuccinate lyase deficiency. Eur J Paediatr Neurol 2012; 16:343-8. [PMID: 21903433 DOI: 10.1016/j.ejpn.2011.08.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2011] [Revised: 08/03/2011] [Accepted: 08/21/2011] [Indexed: 11/19/2022]
Abstract
BACKGROUND Adenylosuccinate lyase (ADSL) deficiency is an autosomal recessive disorder of the purine synthesis which results in accumulation of succinylpurines (succinyladenosine (S-Ado) and succinylamino-imidazole carboxamide riboside (SAICAr)) in body fluids. Patients present developmental delay, often accompanied by epilepsy and autistic spectrum disorders. OBJECTIVES To describe atypical neurological features in the evolution of three novel unrelated cases of ADSL deficiency. PATIENTS A 9-year-old boy with severe cognitive impairment and autistic behaviour received d-ribose therapy for one year. Drug withdrawal was associated with acute neurological deterioration, severe brain atrophy and demyelination on MRI. The second patient is a 5.5-year-old girl with mild developmental delay who presented a benign course with moderate cognitive impairment as the only feature in her evolution. The final patient is a 14-year-old boy with severe cognitive impairment who developed drug-resistant epilepsy and bathing reflex seizures, progressive spasticity in the lower limbs and thoracic deformity. METHODS SAICAr and S-Ado in urine were analysed by HPLC with diode array detection. Diagnosis was confirmed by molecular analysis of the ADSL gene. RESULTS An elevation of S-Ado and SAICAr excretion in urine was detected in all three patients. The patients were homozygous for the missence change p.I369L and for the novel change p.M389V. CONCLUSION Drug-resistant epilepsy and specific therapeutic interventions may modify the neurological outcome in ADSL deficiency. d-ribose must be considered with caution as, in our experience, it returns no clinical benefit and drug withdrawal can precipitate status epilepticus and acute neurological deterioration.
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Affiliation(s)
- Belén Pérez-Dueñas
- Department of Neurology, Hospital Sant Joan de Déu, Passeig Sant Joan de Dèu 2, 08950 Esplugues, Barcelona, Spain.
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18
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van Karnebeek CDM, Stockler S. Treatable inborn errors of metabolism causing intellectual disability: a systematic literature review. Mol Genet Metab 2012; 105:368-81. [PMID: 22212131 DOI: 10.1016/j.ymgme.2011.11.191] [Citation(s) in RCA: 137] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Revised: 11/17/2011] [Accepted: 11/17/2011] [Indexed: 12/30/2022]
Abstract
BACKGROUND Intellectual disability ('developmental delay' at age<5 years) affects 2.5% of population worldwide. Recommendations to investigate genetic causes of intellectual disability are based on frequencies of single conditions and on the yield of diagnostic methods, rather than availability of causal therapy. Inborn errors of metabolism constitute a subgroup of rare genetic conditions for which an increasing number of treatments has become available. To identify all currently treatable inborn errors of metabolism presenting with predominantly intellectual disability, we performed a systematic literature review. METHODS We applied Cochrane Collaboration guidelines in formulation of PICO and definitions, and searched in Pubmed (1960-2011) and relevant (online) textbooks to identify 'all inborn errors of metabolism presenting with intellectual disability as major feature'. We assessed levels of evidence of treatments and characterised the effect of treatments on IQ/development and related outcomes. RESULTS We identified a total of 81 'treatable inborn errors of metabolism' presenting with intellectual disability as a major feature, including disorders of amino acids (n=12), cholesterol and bile acid (n=2), creatine (n=3), fatty aldehydes (n=1); glucose homeostasis and transport (n=2); hyperhomocysteinemia (n=7); lysosomes (n=12), metals (n=3), mitochondria (n=2), neurotransmission (n=7); organic acids (n=19), peroxisomes (n=1), pyrimidines (n=2), urea cycle (n=7), and vitamins/co-factors (n=8). 62% (n=50) of all disorders are identified by metabolic screening tests in blood (plasma amino acids, homocysteine) and urine (creatine metabolites, glycosaminoglycans, oligosaccharides, organic acids, pyrimidines). For the remaining disorders (n=31) a 'single test per single disease' approach including primary molecular analysis is required. Therapeutic modalities include: sick-day management, diet, co-factor/vitamin supplements, substrate inhibition, stemcell transplant, gene therapy. Therapeutic effects include improvement and/or stabilisation of psychomotor/cognitive development, behaviour/psychiatric disturbances, seizures, neurologic and systemic manifestations. The levels of available evidence for the various treatments range from Level 1b,c (n=5); Level 2a,b,c (n=14); Level 4 (n=45), Level 4-5 (n=27). In clinical practice more than 60% of treatments with evidence level 4-5 is internationally accepted as 'standard of care'. CONCLUSION This literature review generated the evidence to prioritise treatability in the diagnostic evaluation of intellectual disability. Our results were translated into digital information tools for the clinician (www.treatable-id.org), which are part of a diagnostic protocol, currently implemented for evaluation of effectiveness in our institution. Treatments for these disorders are relatively accessible, affordable and with acceptable side-effects. Evidence for the majority of the therapies is limited however; international collaborations, patient registries, and novel trial methodologies are key in turning the tide for rare diseases such as these.
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Affiliation(s)
- Clara D M van Karnebeek
- Division of Biochemical Diseases, Department of Pediatrics, BC Children's Hospital, Vancouver BC V6H 3V4, Vancouver, Canada.
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19
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Baresova V, Skopova V, Sikora J, Patterson D, Sovova J, Zikanova M, Kmoch S. Mutations of ATIC and ADSL affect purinosome assembly in cultured skin fibroblasts from patients with AICA-ribosiduria and ADSL deficiency. Hum Mol Genet 2011; 21:1534-43. [PMID: 22180458 DOI: 10.1093/hmg/ddr591] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The purinosome is a multienzyme complex composed by the enzymes active in de novo purine synthesis (DNPS) that cells transiently assemble in their cytosol upon depletion or increased demand of purines. The process of purinosome formation has thus far been demonstrated and studied only in human epithelial cervical cancer cells (HeLa) and human liver carcinoma cells (C3A) transiently expressing recombinant fluorescently labeled DNPS proteins. Using parallel immunolabeling of various DNPS enzymes and confocal fluorescent microscopy, we proved purinosome assembly in HeLa, human hepatocellular liver carcinoma cell line (HepG2), sarcoma osteogenic cells (Saos-2), human embryonic kidney cells (HEK293), human skin fibroblasts (SF) and primary human keratinocytes (KC) cultured in purine-depleted media. Using the identical approach, we proved in cultured skin fibroblasts from patients with AICA-ribosiduria and ADSL deficiency that various mutations of ATIC and ADSL destabilize to various degrees of purinosome assembly and found that the ability to form purinosomes correlates with clinical phenotypes of individual ADSL patients. Our results thus shown that the assembly of functional purinosomes is fully dependent on the presence of structurally unaffected ATIC and ADSL complexes and presumably also on the presence of all the other DNPS proteins. The results also corroborate the hypothesis that the phenotypic severity of ADSL deficiency is mainly determined by structural stability and residual catalytic capacity of the corresponding mutant ADSL protein complexes, as this is prerequisite for the formation and stability of the purinosome and at least partial channeling of succinylaminoimidazolecarboxamide riboside-ADSL enzyme substrates-through the DNPS pathway.
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Affiliation(s)
- Veronika Baresova
- Institute of Inherited Metabolic Disorders, Charles University in Prague and General University Hospital in Prague, 128 08 Prague 2, Czech Republic
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20
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Alcaide P, Merinero B, Ruiz-Sala P, Richard E, Navarrete R, Arias A, Ribes A, Artuch R, Campistol J, Ugarte M, Rodríguez-Pombo P. Defining the pathogenicity of creatine deficiency syndrome. Hum Mutat 2011; 32:282-91. [PMID: 21140503 DOI: 10.1002/humu.21421] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2010] [Accepted: 11/12/2010] [Indexed: 01/09/2023]
Abstract
This work examined nine patients with creatine deficiency syndrome (CDS): six with a creatine transport (CRTR) defect and three with a GAMT defect. Eleven nucleotide variations were detected: six in SLC6A8 and five in GAMT. These changes were analyzed at the mRNA level and specific alleles (most of which bore premature stop codons) were selected as nulls because they provoked nonsense-mediated decay activation. The impact of these CDS mutations on metabolic stress (ROS production, p38MAPK activation, aberrant proliferation and apoptosis) was analyzed in patient fibroblast cultures. Oxidative stress contributed toward the severe form of CDS, with increases seen in the intracellular ROS content and the percentage of apoptotic cells. An altered cell cycle was also seen in a number of CRTR and GAMT fibroblast cell lines (mostly those carrying null alleles). p38MAPK activation only correlated with oxidative stress in the CRTR cells. Based on intracellular creatine levels, the contribution of energy depletion toward metabolic stress was demonstrable only in selected CRTR cells. Together, these findings suggest that the apoptotic response to genotoxic damage in the present CDS cells may have been triggered by different cell signaling pathways. They also suggest that reducing oxidative stress could be helpful in treating CDS. Hum Mutat 32:1-10, 2011. © 2011 Wiley-Liss, Inc.
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Affiliation(s)
- Patricia Alcaide
- Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular "Severo Ochoa" CSIC-UAM, Departamento de Biología Molecular, Universidad Autónoma de Madrid, Spain
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21
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Vliet LK, Wilkinson TG, Duval N, Vacano G, Graham C, Zikánová M, Skopova V, Baresova V, Hnízda A, Kmoch S, Patterson D. Molecular characterization of the AdeI mutant of Chinese hamster ovary cells: a cellular model of adenylosuccinate lyase deficiency. Mol Genet Metab 2011; 102:61-8. [PMID: 20884265 PMCID: PMC3065963 DOI: 10.1016/j.ymgme.2010.08.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2010] [Revised: 08/30/2010] [Accepted: 08/30/2010] [Indexed: 11/19/2022]
Abstract
Adenylosuccinate lyase (ADSL, E. C. 4.3.2.2) carries out two non-sequential steps in de novo AMP synthesis, the conversion of succinylaminoimidazole carboxamide ribotide (SAICAR) to aminoimidazolecarboxamide ribotide (AICAR) and the conversion of succinyl AMP (AMPS) to AMP. In humans, mutations in ADSL lead to an inborn error of metabolism originally characterized by developmental delay, often with autistic features. There is no effective treatment for ADSL deficiency. Hypotheses regarding the pathogenesis include toxicity of high levels of SAICAR, AMPS, or their metabolites, deficiency of the de novo purine biosynthetic pathway, or lack of a completely functional purine cycle in muscle and brain. One important approach to understand ADSL deficiency is to develop cell culture models that allow investigation of the properties of ADSL mutants and the consequences of ADSL deficiency at the cellular level. We previously reported the isolation and initial characterization of mutants of Chinese hamster ovary (CHO-K1) cells (AdeI) that lack detectable ADSL activity, accumulate SAICAR and AMPS, and require adenine for growth. Here we report the cDNA sequences of ADSL from CHO-K1 and AdeI cells and describe a mutation resulting in an alanine to valine amino acid substitution at position 291 (A291V) in AdeI ADSL. This substitution lies in the "signature sequence" of ADSL, inactivates the enzyme, and validates AdeI as a cellular model of ADSL deficiency.
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Affiliation(s)
- Lydia K. Vliet
- Eleanor Roosevelt Institute and Department of Biological Sciences, University of Denver, 2101 E. Wesley Avenue, Denver, CO, 80208
| | - Terry G. Wilkinson
- Eleanor Roosevelt Institute and Department of Biological Sciences, University of Denver, 2101 E. Wesley Avenue, Denver, CO, 80208
| | - Nathan Duval
- Eleanor Roosevelt Institute and Department of Biological Sciences, University of Denver, 2101 E. Wesley Avenue, Denver, CO, 80208
| | - Guido Vacano
- Eleanor Roosevelt Institute and Department of Biological Sciences, University of Denver, 2101 E. Wesley Avenue, Denver, CO, 80208
| | - Christine Graham
- Eleanor Roosevelt Institute and Department of Biological Sciences, University of Denver, 2101 E. Wesley Avenue, Denver, CO, 80208
| | - Marie Zikánová
- Center for Applied Genomics, Charles University in Prague, First Faculty of Medicine, Ke Karlovu 2, 128 00 Prague 2, Czech Republic
- Institute of Inherited Metabolic Disorders, Charles University in Prague, First Faculty of Medicine, Ke Karlovu 2, 128 00 Prague 2, Czech Republic
| | - Vaclava Skopova
- Center for Applied Genomics, Charles University in Prague, First Faculty of Medicine, Ke Karlovu 2, 128 00 Prague 2, Czech Republic
- Institute of Inherited Metabolic Disorders, Charles University in Prague, First Faculty of Medicine, Ke Karlovu 2, 128 00 Prague 2, Czech Republic
| | - Veronika Baresova
- Center for Applied Genomics, Charles University in Prague, First Faculty of Medicine, Ke Karlovu 2, 128 00 Prague 2, Czech Republic
- Institute of Inherited Metabolic Disorders, Charles University in Prague, First Faculty of Medicine, Ke Karlovu 2, 128 00 Prague 2, Czech Republic
| | - Aleš Hnízda
- Institute of Inherited Metabolic Disorders, Charles University in Prague, First Faculty of Medicine, Ke Karlovu 2, 128 00 Prague 2, Czech Republic
| | - Stanislav Kmoch
- Center for Applied Genomics, Charles University in Prague, First Faculty of Medicine, Ke Karlovu 2, 128 00 Prague 2, Czech Republic
- Institute of Inherited Metabolic Disorders, Charles University in Prague, First Faculty of Medicine, Ke Karlovu 2, 128 00 Prague 2, Czech Republic
| | - David Patterson
- Eleanor Roosevelt Institute and Department of Biological Sciences, University of Denver, 2101 E. Wesley Avenue, Denver, CO, 80208
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