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Vallance H, Sinclair G, Rakic B, Stockler-Ipsiroglu S. Diagnostic yield from routine metabolic screening tests in evaluation of global developmental delay and intellectual disability. Paediatr Child Health 2021; 26:344-348. [PMID: 34676012 DOI: 10.1093/pch/pxaa112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 09/06/2020] [Indexed: 11/15/2022] Open
Abstract
Global developmental delay and intellectual disability (GDD/ID) affect 3% of the paediatric population. Although inborn errors of metabolism (IEM) are not a common cause of GDD/ID, early therapeutic intervention can improve neurodevelopmental manifestations. In 2012, a first-tier test panel, including specialized metabolic and routine chemistry tests, was piloted to community-based paediatricians in British Columbia with aims to achieve earlier diagnosis of treatable IEM. Objective The aim of this retrospective review was to evaluate the diagnostic yield from these first-tier tests in the 7 years before (2006 to 2012) and after (2013 to 2019) implementation at the community paediatrician level. Results Prior and postimplementation diagnostic yield of an IEM from first-tier metabolic testing was 9 out of 986 (0.91%) and 11 out of 4,345 children (0.25%), respectively. Disorders of creatine metabolism and organic acidurias were the most frequently established diagnoses in both time periods. No diagnoses were established through acylcarnitine copper/ceruloplasmin, lactate, or ammonia testing. Twenty out of 24 patients had specific neurological or other red flag signs in addition to GDD/ID. Four boys diagnosed with an x-linked creatine transporter defect (CTD) had speech-language delay as the most prominent finding. Conclusions The expansion of first-tier metabolic testing to community-based paediatricians in BC did not yield an increase in IEM diagnoses. A modified first-tier test panel should be offered to patients with GDD/ID, neurologic, and/or red flag signs. Urine creatine testing in boys with speech-language delay warrants consideration to detect CTD.
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Affiliation(s)
- Hilary Vallance
- Department of Pathology and Laboratory Medicine, BC Children's Hospital, Vancouver, British Columbia
| | - Graham Sinclair
- Department of Pathology and Laboratory Medicine, BC Children's Hospital, Vancouver, British Columbia
| | - Bojana Rakic
- Department of Pathology and Laboratory Medicine, BC Children's Hospital, Vancouver, British Columbia
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2
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Kanzi AM, San JE, Chimukangara B, Wilkinson E, Fish M, Ramsuran V, de Oliveira T. Next Generation Sequencing and Bioinformatics Analysis of Family Genetic Inheritance. Front Genet 2020; 11:544162. [PMID: 33193618 PMCID: PMC7649788 DOI: 10.3389/fgene.2020.544162] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 09/21/2020] [Indexed: 12/29/2022] Open
Abstract
Mendelian and complex genetic trait diseases continue to burden and affect society both socially and economically. The lack of effective tests has hampered diagnosis thus, the affected lack proper prognosis. Mendelian diseases are caused by genetic mutations in a singular gene while complex trait diseases are caused by the accumulation of mutations in either linked or unlinked genomic regions. Significant advances have been made in identifying novel diseases associated mutations especially with the introduction of next generation and third generation sequencing. Regardless, some diseases are still without diagnosis as most tests rely on SNP genotyping panels developed from population based genetic analyses. Analysis of family genetic inheritance using whole genomes, whole exomes or a panel of genes has been shown to be effective in identifying disease-causing mutations. In this review, we discuss next generation and third generation sequencing platforms, bioinformatic tools and genetic resources commonly used to analyze family based genomic data with a focus on identifying inherited or novel disease-causing mutations. Additionally, we also highlight the analytical, ethical and regulatory challenges associated with analyzing personal genomes which constitute the data used for family genetic inheritance.
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Affiliation(s)
- Aquillah M. Kanzi
- Kwazulu-Natal Research and Innovation Sequencing Platform (KRISP), School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
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3
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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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Almontashiri NAM, Zha L, Young K, Law T, Kellogg MD, Bodamer OA, Peake RWA. Clinical Validation of Targeted and Untargeted Metabolomics Testing for Genetic Disorders: A 3 Year Comparative Study. Sci Rep 2020; 10:9382. [PMID: 32523032 PMCID: PMC7287104 DOI: 10.1038/s41598-020-66401-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 05/19/2020] [Indexed: 02/04/2023] Open
Abstract
Global untargeted metabolomics (GUM) has entered clinical diagnostics for genetic disorders. We compared the clinical utility of GUM with traditional targeted metabolomics (TM) as a screening tool in patients with established genetic disorders and determined the scope of GUM as a discovery tool in patients with no diagnosis under investigation. We compared TM and GUM data in 226 patients. The first cohort (n = 87) included patients with confirmed inborn errors of metabolism (IEM) and genetic syndromes; the second cohort (n = 139) included patients without diagnosis who were undergoing evaluation for a genetic disorder. In patients with known disorders (n = 87), GUM performed with a sensitivity of 86% (95% CI: 78–91) compared with TM for the detection of 51 diagnostic metabolites. The diagnostic yield of GUM in patients under evaluation with no established diagnosis (n = 139) was 0.7%. GUM successfully detected the majority of diagnostic compounds associated with known IEMs. The diagnostic yield of both targeted and untargeted metabolomics studies is low when assessing patients with non-specific, neurological phenotypes. GUM shows promise as a validation tool for variants of unknown significance in candidate genes in patients with non-specific phenotypes.
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Affiliation(s)
- Naif A M Almontashiri
- Department of Laboratory Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA.,Faculty of Applied Medical Sciences and the Center for Genetics and Inherited Disorders, Taibah University, Almadinah Almunwarah, Saudi Arabia
| | - Li Zha
- Department of Laboratory Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Kim Young
- Department of Laboratory Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Terence Law
- Department of Laboratory Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Mark D Kellogg
- Department of Laboratory Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Olaf A Bodamer
- Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA.,Broad Institute of Harvard University and MIT, Cambridge, Massachusetts, USA
| | - Roy W A Peake
- Department of Laboratory Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
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Bower A, Imbard A, Benoist JF, Pichard S, Rigal O, Baud O, Schiff M. Diagnostic contribution of metabolic workup for neonatal inherited metabolic disorders in the absence of expanded newborn screening. Sci Rep 2019; 9:14098. [PMID: 31575911 PMCID: PMC6773867 DOI: 10.1038/s41598-019-50518-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 09/05/2019] [Indexed: 12/11/2022] Open
Abstract
Inherited metabolic disorders (IMDs) in neonates are a diagnostic and therapeutic challenge for the neonatologist, with the priority being to rapidly flag the treatable diseases. The objective of this study was to evaluate the contribution of targeted metabolic testing for diagnosing suspected IMDs on the basis of suggestive clinical setting or family history in neonates. We conducted an observational study over five years, from January 1st, 2010 to December 31, 2014 in the neonatal intensive care unit (NICU) at Robert Debré University Hospital, Paris, France. We assessed the number of neonates for whom a metabolic testing was performed, the indication for each metabolic test and the diagnostic yield of this selected metabolic workup for diagnosing an IMD. Metabolic testing comprised at least one of the following testings: plasma, urine or cerebrospinal fluid amino acids, urine organic acids, plasma acylcarnitine profile, and urine mucopolysaccharides and oligosaccharides. 11,301 neonates were admitted at the neonatal ICU during the study period. One hundred and ninety six neonates underwent metabolic testing. Eleven cases of IMDs were diagnosed. This diagnostic approach allowed the diagnosis, treatment and survival of 4 neonates (maple syrup urine disease, propionic acidemia, carnitine-acylcarnitine translocase deficiency and type 1 tyrosinemia). In total, metabolic testing was performed for 1.7% of the total number of neonates admitted in the NICU over the study period. These included 23% finally unaffected neonates with transient abnormalities, 5.6% neonates suffering from an identified IMD, 45.4% neonates suffering from a non-metabolic identified disease and 26% neonates with chronic abnormalities but for whom no final causal diagnosis could be made. In conclusion, as expected, such a metabolic targeted workup allowed the diagnosis of classical neonatal onset IMDs in symptomatic newborns. However, this workup remained normal or unspecific for 94.4% of the tested patients. It allowed excluding an IMD in 68.4% of the tested neonates. In spite of the high rate of normal results, such a strategy seems acceptable due to the severity of the symptoms and the need for immediate treatment when available in neonatal IMDs. However, its cost-effectiveness remains low especially in a clinically targeted population in a country where newborn screening is still unavailable for IMDs except for phenylketonuria in 2019.
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Affiliation(s)
- Alexandra Bower
- Neonatal intensive care department, Robert Debré University Hospital, APHP, Paris, 75019, France
- Reference Center for Inborn Errors of Metabolism, Robert Debré University Hospital, APHP, Paris, 75019, France
| | - Apolline Imbard
- Biochemistry Laboratory, Robert Debré University Hospital, APHP, Paris, France
- Paris Sud University, Chatenay Malabry, France
| | - Jean-François Benoist
- Biochemistry Laboratory, Robert Debré University Hospital, APHP, Paris, France
- Paris Sud University, Chatenay Malabry, France
| | - Samia Pichard
- Reference Center for Inborn Errors of Metabolism, Robert Debré University Hospital, APHP, Paris, 75019, France
| | - Odile Rigal
- Biochemistry Laboratory, Robert Debré University Hospital, APHP, Paris, France
| | - Olivier Baud
- Neonatal intensive care department, Robert Debré University Hospital, APHP, Paris, 75019, France
- UMR1141, PROTECT, INSERM, Université de Paris, Paris, 75019, France
| | - Manuel Schiff
- Reference Center for Inborn Errors of Metabolism, Robert Debré University Hospital, APHP, Paris, 75019, France.
- UMR1141, PROTECT, INSERM, Université de Paris, Paris, 75019, France.
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Kuiper GA, Meijer OLM, Langereis EJ, Wijburg FA. Failure to shorten the diagnostic delay in two ultra-orphan diseases (mucopolysaccharidosis types I and III): potential causes and implications. Orphanet J Rare Dis 2018; 13:2. [PMID: 29310675 PMCID: PMC5759238 DOI: 10.1186/s13023-017-0733-y] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 12/04/2017] [Indexed: 12/04/2022] Open
Abstract
Background Rare diseases are often un- or misdiagnosed for extended periods, resulting in a long diagnostic delay that may significantly add to the burden of the disease. An early diagnosis is particularly essential if a disease-modifying treatment is available. The purpose of this study was to assess the extent of the diagnostic delay in the two ultra-rare diseases, i.e., mucopolysaccharidosis I (MPS I) and III (MPS III), both of which are lysosomal storage disorders with different phenotypic severities (MPS 1 is characterized by the severe Hurler and the more attenuated non-Hurler phenotypes, MPS III is characterized by the severe rapidly progressing (RP) phenotype and more attenuated slowly progressing (SP) phenotype). We investigated whether the diagnostic delay changed over the previous decades. Results The diagnostic delay, which is defined as the time between the first visit to a medical doctor for disease-related symptoms and the final diagnosis, was assessed using telephone interviews with patients diagnosed between 1988 and 2017 and/or their parents or legal guardian(s). In addition, the medical charts were reviewed. For MPS I (n = 29), the median diagnostic delay was 8 months (range 1-24 months) for Hurler patients and 28 months (range 2-147 months) for non-Hurler patients. For MPS III (n = 46), the median diagnostic delay was 33 months (range 1-365 months). No difference was observed between the RP and SP phenotypic groups. Comparing the diagnostic delay over time using 5-year time intervals, no reduction in the diagnostic delay was observed for MPS I or MPS III. Conclusions In the Netherlands, the time to diagnosis for patients with MPS I and MPS III has not changed between 1988 and 2017, and an extensive delay still exists between the first visit to a medical doctor for disease-related symptoms and the final diagnosis. The numerous campaigns launched to increase awareness, leading to earlier diagnosis of these rare disorders, particularly of MPS I, have failed to achieve their goal. Robust selected screening protocols embedded in national guidelines and newborn screening for disorders that meet the criteria for population screening may be the only effective approaches for reducing the diagnostic delay.
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Affiliation(s)
- Gé-Ann Kuiper
- Department of Pediatric Metabolic Diseases, Emma Children's Hospital and Amsterdam Lysosome Center "Sphinx", Academic Medical Center, Meibergdreef 9, 1105, AZ, Amsterdam, The Netherlands
| | - Olga L M Meijer
- Department of Pediatric Metabolic Diseases, Emma Children's Hospital and Amsterdam Lysosome Center "Sphinx", Academic Medical Center, Meibergdreef 9, 1105, AZ, Amsterdam, The Netherlands
| | - Eveline J Langereis
- Department of Pediatric Metabolic Diseases, Emma Children's Hospital and Amsterdam Lysosome Center "Sphinx", Academic Medical Center, Meibergdreef 9, 1105, AZ, Amsterdam, The Netherlands
| | - Frits A Wijburg
- Department of Pediatric Metabolic Diseases, Emma Children's Hospital and Amsterdam Lysosome Center "Sphinx", Academic Medical Center, Meibergdreef 9, 1105, AZ, Amsterdam, The Netherlands.
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Mithyantha R, Kneen R, McCann E, Gladstone M. Current evidence-based recommendations on investigating children with global developmental delay. Arch Dis Child 2017; 102:1071-1076. [PMID: 29054862 PMCID: PMC5738593 DOI: 10.1136/archdischild-2016-311271] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 09/20/2017] [Accepted: 09/21/2017] [Indexed: 12/17/2022]
Abstract
INTRODUCTION Global developmental delay (GDD) affects 1%-3% of the population of children under 5 years of age, making it one of the most common conditions presenting in paediatric clinics; causes are exogenous, genetic (non-metabolic) or genetic (metabolic). Recent advances in biotechnology and genetic testing mean that the investigations available to perform for children under 5 years are increasing and are more sensitive than previously. This change in availability and type of testing necessitates an update in the recommendations for investigating GDD. METHODS We conducted a review of the literature from 2006 to 2016 to identify articles with evidence relating to the investigation of developmental delay in children under the age of 5 years. We collated the evidence into first-line and second-line investigations and, where available, on their yield and cost implications. RESULTS We have provided up-to-date guidance for first-line and second-line investigations for children with GDD under the age of 5 years. Recent evidence demonstrates that genetic testing for all children with unexplained GDD should be first line, if an exogenous cause is not already established. Our review of the literature demonstrates that all patients, irrespective of severity of GDD, should have investigations for treatable conditions. Evidence demonstrates that the yield for treatable conditions is higher than previously thought and that investigations for these metabolic conditions should be considered as first line. Additional second-line investigations can be led by history, examination and developmental trajectories. DISCUSSION We may need to update present recommendations in the UK for investigation of developmental delay. This would include microarray testing as first line and a more thorough approach to investigations for metabolic disorders that can be treated. Clinical assessment remains vital for guiding investigations.
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Affiliation(s)
- Renuka Mithyantha
- Department of Developmental Paediatrics, Alder Hey Children’s NHS Foundation Trust, Liverpool, UK
| | - Rachel Kneen
- Department of Paediatric Neurology, Alder Hey Children’s NHS Foundation Trust, Liverpool, UK,Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
| | - Emma McCann
- Department of Clinical Genetics, Liverpool Women’s Hospital, Liverpool, UK
| | - Melissa Gladstone
- Department of Developmental Paediatrics, Alder Hey Children’s NHS Foundation Trust, Liverpool, UK,Department of Women and Children’s Health, Institute of Translational Medicine, University of Liverpool, Alder Hey Children’s NHS Foundation Trust, Liverpool, UK
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Puri RD, Tuteja M, Verma IC. Genetic Approach to Diagnosis of Intellectual Disability. Indian J Pediatr 2016; 83:1141-9. [PMID: 27619815 DOI: 10.1007/s12098-016-2205-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 07/20/2016] [Indexed: 01/29/2023]
Abstract
Intellectual disability is a non-specific phenotype present in a genetically heterogeneous group of disorders. It is characterized by deficits in intellectual and adaptive functioning, presenting before 18 y of age. Identifying the cause of ID is important to provide treatment where available, genetic counseling, recurrence risks and reproductive options for subsequent pregnancies. Advances in technology, especially next generation sequencing and microarrays, have greatly increased the diagnostic yield of evaluation in cases of ID. This paper describes the points in history taking and examination in the evaluation of a proband, and discusses the proper use of newer diagnostic technologies.
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Affiliation(s)
- Ratna Dua Puri
- Ganga Ram Institute of Postgraduate Medical Research and Education, Institute of Medical Genetics & Genomics, Sir Ganga Ram Hospital, New Delhi, 110060, India.
| | - Moni Tuteja
- Ganga Ram Institute of Postgraduate Medical Research and Education, Institute of Medical Genetics & Genomics, Sir Ganga Ram Hospital, New Delhi, 110060, India
| | - I C Verma
- Ganga Ram Institute of Postgraduate Medical Research and Education, Institute of Medical Genetics & Genomics, Sir Ganga Ram Hospital, New Delhi, 110060, India
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Monroe GR, Frederix GW, Savelberg SMC, de Vries TI, Duran KJ, van der Smagt JJ, Terhal PA, van Hasselt PM, Kroes HY, Verhoeven-Duif NM, Nijman IJ, Carbo EC, van Gassen KL, Knoers NV, Hövels AM, van Haelst MM, Visser G, van Haaften G. Effectiveness of whole-exome sequencing and costs of the traditional diagnostic trajectory in children with intellectual disability. Genet Med 2016; 18:949-56. [DOI: 10.1038/gim.2015.200] [Citation(s) in RCA: 126] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 11/30/2015] [Indexed: 11/09/2022] Open
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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 CD, Stockler-Ipsiroglu S. Early identification of treatable inborn errors of metabolism in children with intellectual disability: The Treatable Intellectual Disability Endeavor protocol in British Columbia. Paediatr Child Health 2014; 19:469-71. [PMID: 25414581 DOI: 10.1093/pch/19.9.469] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/09/2014] [Indexed: 12/25/2022] Open
Affiliation(s)
- Clara Dm van Karnebeek
- Division of Biochemical Diseases, Department of Pediatrics, BC Children's Hospital, Child & Family Research Institute, University of British Columbia; ; Treatable Intellectual Disability Endeavor in British Columbia (TIDE-BC); ; Centre for Molecular Medicine & Therapeutics, Vancouver, British Columbia
| | - Sylvia Stockler-Ipsiroglu
- Division of Biochemical Diseases, Department of Pediatrics, BC Children's Hospital, Child & Family Research Institute, University of British Columbia; ; Treatable Intellectual Disability Endeavor in British Columbia (TIDE-BC)
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Abstract
Background:Identification of the underlying cause of intellectual disability (ID) is important as it improves genetic counselling, management, adaptation; yet its etiologic heterogeneity is challenging and often leads to an expensive work-up.Methods:To improve this diagnostic trajectory, the multidisciplinary Complex Diagnostic Clinic (CDC) was established for ID patients with unexplained complex systemic and/or neurologic features that were referred to the CDC and evaluated by three medical specialists followed by multi-disciplinary rounds. Analyses included surveys and interviews, (retrospective) chart review, costs calculations and comparison.Results:24 children (9 male) were evaluated during seven clinics held over 16 months. The average patient age was 7 years 11 months (range 9 months-18 years). All the children had previously been seen by 2–10 specialist services. The diagnostic yield of the CDC was higher than expected with confirmed and working diagnoses in 11 (46%) and 9 (38%) children respectively. Cost-savings included fewer trips to hospital and fewer tests via more streamlined evaluations. Positive feedback was received from both families and medical professionals.Conclusions:The CDC represents an innovative model of personalized care. Specialist collaboration in the interpretation of relevant clinical, biochemical and genomic data resulted in diagnoses, where none had previously been possible.
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Moeschler JB, Shevell M. Comprehensive evaluation of the child with intellectual disability or global developmental delays. Pediatrics 2014; 134:e903-18. [PMID: 25157020 PMCID: PMC9923626 DOI: 10.1542/peds.2014-1839] [Citation(s) in RCA: 332] [Impact Index Per Article: 33.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Global developmental delay and intellectual disability are relatively common pediatric conditions. This report describes the recommended clinical genetics diagnostic approach. The report is based on a review of published reports, most consisting of medium to large case series of diagnostic tests used, and the proportion of those that led to a diagnosis in such patients. Chromosome microarray is designated as a first-line test and replaces the standard karyotype and fluorescent in situ hybridization subtelomere tests for the child with intellectual disability of unknown etiology. Fragile X testing remains an important first-line test. The importance of considering testing for inborn errors of metabolism in this population is supported by a recent systematic review of the literature and several case series recently published. The role of brain MRI remains important in certain patients. There is also a discussion of the emerging literature on the use of whole-exome sequencing as a diagnostic test in this population. Finally, the importance of intentional comanagement among families, the medical home, and the clinical genetics specialty clinic is discussed.
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Krishnamoorthy KS, Eichler F, Rapalino O, Frosch MP. Case records of the Massachusetts General Hospital. Case 14-2014. An 11-month-old girl with developmental delay. N Engl J Med 2014; 370:1830-41. [PMID: 24806163 DOI: 10.1056/nejmcpc1305987] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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15
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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: 87] [Impact Index Per Article: 8.7] [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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Shashi V, McConkie-Rosell A, Rosell B, Schoch K, Vellore K, McDonald M, Jiang YH, Xie P, Need A, Goldstein DB, Goldstein DG. The utility of the traditional medical genetics diagnostic evaluation in the context of next-generation sequencing for undiagnosed genetic disorders. Genet Med 2013; 16:176-82. [PMID: 23928913 DOI: 10.1038/gim.2013.99] [Citation(s) in RCA: 196] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Accepted: 06/11/2013] [Indexed: 12/16/2022] Open
Abstract
PURPOSE The purpose of this study was to assess the diagnostic yield of the traditional, comprehensive clinical evaluation and targeted genetic testing, within a general genetics clinic. These data are critically needed to develop clinically and economically grounded diagnostic algorithms that consider presenting phenotype, traditional genetics testing, and the emerging role of next-generation sequencing (whole-exome/genome sequencing). METHODS We retrospectively analyzed a cohort of 500 unselected consecutive patients who received traditional genetic diagnostic evaluations at a tertiary medical center. We calculated the diagnosis rate, number of visits to diagnosis, genetic tests, and the cost of testing. RESULTS Thirty-nine patients were determined to not have a genetic disorder; 212 of the remaining 461 (46%) received a genetic diagnosis, and 72% of these were diagnosed on the first visit. The cost per subsequent successful genetic diagnosis was estimated at $25,000. CONCLUSION Almost half of the patients were diagnosed using the traditional approach, most at the initial visit. For those remaining undiagnosed, next-generation sequencing may be clinically and economically beneficial. Estimating a 50% success rate for next-generation sequencing in undiagnosed genetic disorders, its application after the first clinical visit could result in a higher rate of genetic diagnosis at a considerable cost savings per successful diagnosis.
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Affiliation(s)
- Vandana Shashi
- Department of Pediatrics, Division of Medical Genetics, Duke University Medical Center, Durham, North Carolina, USA
| | - Allyn McConkie-Rosell
- Department of Pediatrics, Division of Medical Genetics, Duke University Medical Center, Durham, North Carolina, USA
| | - Bruce Rosell
- Department of Pediatrics, Division of Medical Genetics, Duke University Medical Center, Durham, North Carolina, USA
| | - Kelly Schoch
- Department of Pediatrics, Division of Medical Genetics, Duke University Medical Center, Durham, North Carolina, USA
| | - Kasturi Vellore
- Department of Pediatrics, Division of Medical Genetics, Duke University Medical Center, Durham, North Carolina, USA
| | - Marie McDonald
- Department of Pediatrics, Division of Medical Genetics, Duke University Medical Center, Durham, North Carolina, USA
| | - Yong-Hui Jiang
- Department of Pediatrics, Division of Medical Genetics, Duke University Medical Center, Durham, North Carolina, USA
| | - Pingxing Xie
- Center for Human Genome Variation, Duke University Medical Center, Durham, North Carolina, USA
| | - Anna Need
- Center for Human Genome Variation, Duke University Medical Center, Durham, North Carolina, USA
| | | | - David G Goldstein
- Center for Human Genome Variation, Duke University Medical Center, Durham, North Carolina, USA
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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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Abstract
Ever since its original description by Leo Kanner in l943, autism has been generally defined by its clinical characteristics and core symptoms that include impaired social skills, isolated areas of interest, and delayed and disordered language. Over time, it has become apparent that autism is a heterogeneous disorder with regard to its clinical presentation, etiology, underlying neurobiology, and degree of severity. As a result, the termed diagnosis of autism spectrum disorders (ASDs) has come into common usage. With advancements in clinical care, there has come the appreciation that many ASD children, adolescents, and adults may have medically relevant disorders that may negatively impact their developmental progress and behavior, but which frequently go undetected. Many of these medical conditions are treatable, often resulting in improved developmental gains and quality of life for the patient and family. In addition, the possibility exists that some of these medical conditions may suggest the presence of important genetic and/or biologic markers, which, if identified, can refine our ability to be more precise in categorizing clinical and genetic subtypes within the autism spectrum.
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Affiliation(s)
- Margaret L Bauman
- Department of Neurology, and Lurie Center LADDERS program, Massachusetts General Hospital, Boston, MA 02421, USA.
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van der Ham M, de Koning TJ, Lefeber D, Fleer A, Prinsen BH, de Sain-van der Velden MG. Liquid chromatography–tandem mass spectrometry assay for the quantification of free and total sialic acid in human cerebrospinal fluid. J Chromatogr B Analyt Technol Biomed Life Sci 2010; 878:1098-102. [DOI: 10.1016/j.jchromb.2010.03.020] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2009] [Revised: 03/03/2010] [Accepted: 03/11/2010] [Indexed: 10/19/2022]
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Engbers HM, Nievelstein RAJ, Gooskens RHJM, Kroes HY, Van Empelen R, Braams O, Wittebol-Post D, Hendriks MMWB, Visser G. The clinical utility of MRI in patients with neurodevelopmental disorders of unknown origin. Eur J Neurol 2010; 17:815-22. [DOI: 10.1111/j.1468-1331.2009.02927.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Engbers HM, Berger R, van Hasselt P, de Koning T, de Sain-van der Velden MGM, Kroes H, Visser G. Reply. Ann Neurol 2009. [DOI: 10.1002/ana.21701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Shevell M. Metabolic evaluation in neurodevelopmental disabilities. Ann Neurol 2009; 65:483-4; author reply 484. [DOI: 10.1002/ana.21574] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Rapin I. To test or not to test children with developmental disorders. Ann Neurol 2009; 65:483; author reply 484. [DOI: 10.1002/ana.21561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Mueller S, Sherr EH. The importance of metabolic testing in the evaluation of intellectual disability. Ann Neurol 2008; 64:113-4. [DOI: 10.1002/ana.21468] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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