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Li H, Shao F, Zhou W. Newborn screening for isovaleric acidemia: A case report of a Chinese patient with novel variants. Mol Genet Metab Rep 2024; 39:101088. [PMID: 38736698 PMCID: PMC11088185 DOI: 10.1016/j.ymgmr.2024.101088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Revised: 04/24/2024] [Accepted: 04/29/2024] [Indexed: 05/14/2024] Open
Abstract
Isovaleric acidemia (IVA) is a rare autosomal recessive disorder that manifests as a deficiency of isovaleryl-CoA dehydrogenase (IVD), a key enzyme in leucine metabolism. The clinical presentations associated with IVD deficiency are variable and include feeding intolerance, vomiting, metabolic acidosis, ketonemia, "sweaty feet" odor, lethargy, coma and even death. Tandem mass spectrometry (MS/MS) and gas chromatography-mass spectrometry (GC/MS) methods were used to perform organic acid analysis of blood and urine samples from IVA patients, and the genetic analysis included next generation sequencing (NGS) and Sanger sequencing of the IVD gene. Here, we report the case of an almost seven-year-old male patient from a Chinese family who was asymptomatic during the newborn period, including the clinical manifestations and examination results. Genetic analysis revealed a previously unreported compound heterozygous variant in the IVD gene: c.593G > C (p.W198S) and c.859C > T (p.R287W).
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Affiliation(s)
- Huizhong Li
- Neonatal Disease Screening Center, The Affiliated Xuzhou Maternity and Child Health Care Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Fang Shao
- Neonatal Disease Screening Center, The Affiliated Xuzhou Maternity and Child Health Care Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Wei Zhou
- Neonatal Disease Screening Center, The Affiliated Xuzhou Maternity and Child Health Care Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, China
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Pajares-García S, González de Aledo-Castillo JM, Flores-Jiménez JE, Collado T, Pérez J, Paredes-Fuentes AJ, Argudo-Ramírez A, López-Galera RM, Prats B, García-Villoria J. Analysis of a second-tier test panel in dried blood spot samples using liquid chromatography-tandem mass spectrometry in Catalonia's newborn screening programme. Clin Chem Lab Med 2024; 62:493-505. [PMID: 37794778 DOI: 10.1515/cclm-2023-0216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 09/21/2023] [Indexed: 10/06/2023]
Abstract
OBJECTIVES Acylcarnitine and amino acid analyses of dried blood spot (DBS) samples using tandem mass spectrometry in newborn screening (NBS) programmes can generate false positive (FP) results. Therefore, implementation of second-tier tests (2TTs) using DBS samples has become increasingly important to avoid FPs. The most widely used 2TT metabolites include methylmalonic acid, 3-hydroxypropionic acid, methylcitric acid, and homocysteine. METHODS We simultaneously measured 46 underivatised metabolites, including organic acids, acylglycine and acylcarnitine isomers, homocysteine, and orotic acid, in DBS samples using tandem mass spectrometry. To validate this method, we analysed samples from 147 healthy newborns, 160 patients with genetic disorders diagnosed via NBS, 20 patients with acquired vitamin B12 deficiency, 10 newborns receiving antibiotic treatment, and nine external quality control samples. RESULTS The validation study revealed that 31 metabolites showed good analytical performance. Furthermore, this method detected key metabolites for all diseases associated with increased levels of the following acylcarnitines: C3, C4, C5, C4DC/C5OH, and C5DC. The sensitivity of this method to detect all diseases was 100 %, and the specificity was 74-99 %, except for glutaric aciduria type 1. This method can also be used to diagnose mitochondrial fatty acid β-oxidation disorders (FAODs) and urea cycle defects (UCDs). CONCLUSIONS We have described a 2TT panel of 31 metabolites in DBS samples based on an easy and rapid method without derivatisation. Its implementation allowed us to distinguish between different organic acidurias, some FAODs, and UCDs. This new strategy has increased the efficiency of our NBS programme by reducing FP and false negative results, second sample requests, and the time required for diagnosis.
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Affiliation(s)
- Sonia Pajares-García
- Department of Biochemistry and Molecular Genetics, Section of Inborn Errors of Metabolism-IBC, Hospital Clinic, Barcelona, Spain
- Center for Biomedical Research Network on Rare Diseases (CIBERER), Madrid, Spain
| | | | - José Eduardo Flores-Jiménez
- Department of Biochemistry and Molecular Genetics, Section of Inborn Errors of Metabolism-IBC, Hospital Clinic, Barcelona, Spain
| | - Tatiana Collado
- Department of Biochemistry and Molecular Genetics, Section of Inborn Errors of Metabolism-IBC, Hospital Clinic, Barcelona, Spain
| | - Judit Pérez
- Department of Biochemistry and Molecular Genetics, Section of Inborn Errors of Metabolism-IBC, Hospital Clinic, Barcelona, Spain
| | - Abraham José Paredes-Fuentes
- Department of Biochemistry and Molecular Genetics, Section of Inborn Errors of Metabolism-IBC, Hospital Clinic, Barcelona, Spain
| | - Ana Argudo-Ramírez
- Department of Biochemistry and Molecular Genetics, Section of Inborn Errors of Metabolism-IBC, Hospital Clinic, Barcelona, Spain
| | - Rosa María López-Galera
- Department of Biochemistry and Molecular Genetics, Section of Inborn Errors of Metabolism-IBC, Hospital Clinic, Barcelona, Spain
- Center for Biomedical Research Network on Rare Diseases (CIBERER), Madrid, Spain
- Biomedical Research Institute, August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Blanca Prats
- Health Department, Maternal and Child Health Service, Public Health Agency of Catalonia, The Government of Catalonia, Barcelona, Spain
| | - Judit García-Villoria
- Department of Biochemistry and Molecular Genetics, Section of Inborn Errors of Metabolism-IBC, Hospital Clinic, Barcelona, Spain
- Center for Biomedical Research Network on Rare Diseases (CIBERER), Madrid, Spain
- Biomedical Research Institute, August Pi i Sunyer (IDIBAPS), Barcelona, Spain
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Messina M, Arena A, Iacobacci R, La Spina L, Meli C, Raudino F, Ruggieri M. Butyrylcarnitine Elevation in Newborn Screening: Reducing False Positives and Distinguishing between Two Rare Diseases through the Evaluation of New Ratios. Biomedicines 2023; 11:3247. [PMID: 38137468 PMCID: PMC10741594 DOI: 10.3390/biomedicines11123247] [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: 10/08/2023] [Revised: 11/20/2023] [Accepted: 11/29/2023] [Indexed: 12/24/2023] Open
Abstract
One of the main challenges of newborn screening programs, which screen for inherited metabolic disorders, is cutting down on false positives (FPs) in order to avoid family stresses, additional analyses, and unnecessary costs. False positives are partly caused by an insubstantial number of robust biomarkers in evaluations. Another challenge is how to distinguish between diseases which share the same primary marker and for which secondary biomarkers are just as highly desirable. Focusing on pathologies that involve butyrylcarnitine (C4) elevation, such as short-chain acylCoA dehydrogenase deficiency (SCADD) and isobutyrylCoA dehydrogenase deficiency (IBDD), we investigated the acylcarnitine profile of 121 newborns with a C4 increase to discover secondary markers to achieve two goals: reduce the FP rate and discriminate between the two rare diseases. Analyses were carried out using tandem mass spectrometry with whole blood samples spotted on filter paper. Seven new biomarkers (C4/C0, C4/C5, C4/C5DC\C6OH, C4/C6, C4/C8, C4/C14:1, C4/C16:1) were identified using a non-parametric ANOVA analysis. Then, the corresponding cut-off values were found and applied to the screening program. The seven new ratios were shown to be robust (p < 0.001 and p < 0.01, 0.0937 < ε2 < 0.231) in discriminating between FP and IBDD patients, FP and SCADD patients, or SCADD and IBDD patients. Our results suggest that the new ratios are optimal indicators for identifying true positives, distinguishing between two rare diseases that share the same primary biomarker, improving the predictive positive value (PPV) and reducing the false positive rate (FPR).
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Affiliation(s)
- MariaAnna Messina
- Expanded Newborn Screening Laboratory, Newborn Screening and Metabolic Diseases Unit, University-Polyclinic “G. Rodolico-San Marco”, 95123 Catania, Italy; (A.A.); (R.I.); (L.L.S.); (C.M.); (F.R.); (M.R.)
| | - Alessia Arena
- Expanded Newborn Screening Laboratory, Newborn Screening and Metabolic Diseases Unit, University-Polyclinic “G. Rodolico-San Marco”, 95123 Catania, Italy; (A.A.); (R.I.); (L.L.S.); (C.M.); (F.R.); (M.R.)
| | - Riccardo Iacobacci
- Expanded Newborn Screening Laboratory, Newborn Screening and Metabolic Diseases Unit, University-Polyclinic “G. Rodolico-San Marco”, 95123 Catania, Italy; (A.A.); (R.I.); (L.L.S.); (C.M.); (F.R.); (M.R.)
| | - Luisa La Spina
- Expanded Newborn Screening Laboratory, Newborn Screening and Metabolic Diseases Unit, University-Polyclinic “G. Rodolico-San Marco”, 95123 Catania, Italy; (A.A.); (R.I.); (L.L.S.); (C.M.); (F.R.); (M.R.)
| | - Concetta Meli
- Expanded Newborn Screening Laboratory, Newborn Screening and Metabolic Diseases Unit, University-Polyclinic “G. Rodolico-San Marco”, 95123 Catania, Italy; (A.A.); (R.I.); (L.L.S.); (C.M.); (F.R.); (M.R.)
| | - Federica Raudino
- Expanded Newborn Screening Laboratory, Newborn Screening and Metabolic Diseases Unit, University-Polyclinic “G. Rodolico-San Marco”, 95123 Catania, Italy; (A.A.); (R.I.); (L.L.S.); (C.M.); (F.R.); (M.R.)
| | - Martino Ruggieri
- Expanded Newborn Screening Laboratory, Newborn Screening and Metabolic Diseases Unit, University-Polyclinic “G. Rodolico-San Marco”, 95123 Catania, Italy; (A.A.); (R.I.); (L.L.S.); (C.M.); (F.R.); (M.R.)
- Unit of Clinical Pediatrics, Department of Clinical and Experimental Medicine, University of Catania, 95123 Catania, Italy
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Sharo AG, Zou Y, Adhikari AN, Brenner SE. ClinVar and HGMD genomic variant classification accuracy has improved over time, as measured by implied disease burden. Genome Med 2023; 15:51. [PMID: 37443081 PMCID: PMC10347827 DOI: 10.1186/s13073-023-01199-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Accepted: 05/31/2023] [Indexed: 07/15/2023] Open
Abstract
BACKGROUND Curated databases of genetic variants assist clinicians and researchers in interpreting genetic variation. Yet, these databases contain some misclassified variants. It is unclear whether variant misclassification is abating as these databases rapidly grow and implement new guidelines. METHODS Using archives of ClinVar and HGMD, we investigated how variant misclassification has changed over 6 years, across different ancestry groups. We considered inborn errors of metabolism (IEMs) screened in newborns as a model system because these disorders are often highly penetrant with neonatal phenotypes. We used samples from the 1000 Genomes Project (1KGP) to identify individuals with genotypes that were classified by the databases as pathogenic. Due to the rarity of IEMs, nearly all such classified pathogenic genotypes indicate likely variant misclassification in ClinVar or HGMD. RESULTS While the false-positive rates of both ClinVar and HGMD have improved over time, HGMD variants currently imply two orders of magnitude more affected individuals in 1KGP than ClinVar variants. We observed that African ancestry individuals have a significantly increased chance of being incorrectly indicated to be affected by a screened IEM when HGMD variants are used. However, this bias affecting genomes of African ancestry was no longer significant once common variants were removed in accordance with recent variant classification guidelines. We discovered that ClinVar variants classified as Pathogenic or Likely Pathogenic are reclassified sixfold more often than DM or DM? variants in HGMD, which has likely resulted in ClinVar's lower false-positive rate. CONCLUSIONS Considering misclassified variants that have since been reclassified reveals our increasing understanding of rare genetic variation. We found that variant classification guidelines and allele frequency databases comprising genetically diverse samples are important factors in reclassification. We also discovered that ClinVar variants common in European and South Asian individuals were more likely to be reclassified to a lower confidence category, perhaps due to an increased chance of these variants being classified by multiple submitters. We discuss features for variant classification databases that would support their continued improvement.
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Affiliation(s)
- Andrew G. Sharo
- Biophysics Graduate Group, University of California, Berkeley, CA 94720 USA
- Center for Computational Biology, University of California, Berkeley, CA 94720 USA
- Department of Ecology and Evolutionary Biology, University of California, 124 Biomed Building, 1156 High St., Santa Cruz, CA 95064 USA
| | - Yangyun Zou
- Center for Computational Biology, University of California, Berkeley, CA 94720 USA
- Department of Plant and Microbial Biology, University of California, 461 Koshland Hall, Berkeley, CA 94720 USA
- Currently at: Department of Clinical Research, Yikon Genomics Company, Ltd., Shanghai, China
| | - Aashish N. Adhikari
- Center for Computational Biology, University of California, Berkeley, CA 94720 USA
- Department of Plant and Microbial Biology, University of California, 461 Koshland Hall, Berkeley, CA 94720 USA
- Currently at: Illumina, Foster City, CA 94404 USA
| | - Steven E. Brenner
- Biophysics Graduate Group, University of California, Berkeley, CA 94720 USA
- Center for Computational Biology, University of California, Berkeley, CA 94720 USA
- Department of Plant and Microbial Biology, University of California, 461 Koshland Hall, Berkeley, CA 94720 USA
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Breilyn MS, Kenny EE, Abul-Husn NS. Diverse and unselected adults with clinically relevant ACADS variants lack evidence of metabolic disease. Mol Genet Metab 2023; 138:106971. [PMID: 36549199 PMCID: PMC10038226 DOI: 10.1016/j.ymgme.2022.106971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 12/12/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022]
Abstract
INTRODUCTION The clinical significance of Short-chain acyl CoA dehydrogenase deficiency (SCADD), caused by biallelic variation in the ACADS gene, is contested. Clinically ascertained individuals have a range of reported metabolic and physical symptoms. Conversely, individuals identified through newborn screening remain overwhelmingly asymptomatic. Two common ACADS variants, c.511C > T (p.Arg171Trp) and c.625G > A (p.Gly209Ser) are known to reduce enzymatic activity with undetermined clinical correlate. We applied a genome-first approach to evaluate the prevalence and clinical consequences of ACADS variants in an ancestrally diverse and unselected patient population. MATERIAL AND METHODS We used exome sequence data linked to electronic health records (EHRs) to identify clinically relevant ACADS variants, and estimate their prevalence and clinical implications in 27,447 ancestrally diverse and unrelated adults from the BioMe Biobank in New York, NY. We extracted International Classification of Diseases, ninth (ICD-9) and tenth (ICD-10) revision codes corresponding to eight SCADD-associated phenotypes relevant to adults from participants' EHRs. Phenotypes included intellectual disability, behavioral disorders with onset in childhood, epilepsy or seizure disorders, hypoglycemia, muscle weakness, metabolic acidosis, fatty liver, and a diagnosis of SCADD or disorder of fatty acid oxidation. We performed manual chart reviews for individuals homozygous for rare pathogenic variants. Multivariate logistic regression was used to determine the association between clinically relevant ACADS variants and phenotypes of interest. RESULTS 1 in 10,000 BioMe participants were homozygous for rare pathogenic variants (PVs) in ACADS, 1 in 20 were homozygous or presumed compound heterozygous for common variants (CVs), and 1 in 300 harbored both a PV and a CV. Of the 2035 variant positive individuals, none had a documented diagnosis of SCADD. We identified five PV/PV positive individuals, none of whom had evidence of symptomatic SCADD on manual chart review. CV/CV positive and CV/PV positive individuals did not have increased odds of any of the eight ACADS phenotypes evaluated compared to variant negative individuals (OR for CV/CV 0.99, 95% CI 0.86-1.1, p = .88; OR for CV/PV OR 1.49, 95% CI 0.87-2.6, p = .15). CONCLUSIONS The prevalence of clinically relevant ACADS variants in an unselected population was higher than previously reported SCADD prevalence of 1 in 35,000 in the United States. Clinically relevant variants in ACADS were not associated with evidence of metabolic disease in a large and ancestrally diverse adult population. These findings support the assertion that SCADD is more likely a biochemical entity without clinical correlate, in particular when caused by one or more common variants.
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Affiliation(s)
- Margo S Breilyn
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| | - Eimear E Kenny
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Institute for Genomic Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Noura S Abul-Husn
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Institute for Genomic Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA; 23andMe Inc., Sunnyvale, CA, United States of America; Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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Liquid Chromatography-Tandem Mass Spectrometry in Newborn Screening Laboratories. Int J Neonatal Screen 2022; 8:ijns8040062. [PMID: 36547379 PMCID: PMC9781967 DOI: 10.3390/ijns8040062] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 11/11/2022] [Accepted: 11/16/2022] [Indexed: 11/29/2022] Open
Abstract
Tandem mass spectrometry (MS/MS) is the most universal platform currently available for the analysis of enzymatic activities and biomarkers in dried blood spots (DBS) for applications in newborn screening (NBS). Among the MS/MS applications in NBS, the most common is flow-injection analysis (FIA-) MS/MS, where the sample is introduced as a bolus injection into the mass spectrometer without the prior fractionation of analytes. Liquid chromatography combined with MS/MS (LC-MS/MS) has been employed for second-tier tests to reduce the false-positive rate associated with several nonspecific screening markers, beginning two decades ago. More recently, LC-MS/MS has been applied to primary screening for new conditions for which FIA-MS/MS or other methods, including genomic screening, are not yet adequate. In addition to providing a list of the currently used LC-MS/MS-based assays for NBS, the authors share their experience regarding the maintenance requirements of LC-MS/MS vs. FIA-MS/MS systems. The consensus is that the maintenance of LC-MS/MS and FIA-MS/MS instrumentation is similar, and LC-MS/MS has the advantage of allowing for a larger number of diseases to be screened for in a multiplex, cost-effective fashion with a high throughput and an adequate turnaround time.
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Minear MA, Phillips MN, Kau A, Parisi MA. Newborn screening research sponsored by the NIH: From diagnostic paradigms to precision therapeutics. AMERICAN JOURNAL OF MEDICAL GENETICS. PART C, SEMINARS IN MEDICAL GENETICS 2022; 190:138-152. [PMID: 36102292 PMCID: PMC10328555 DOI: 10.1002/ajmg.c.31997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 08/21/2022] [Accepted: 08/24/2022] [Indexed: 06/15/2023]
Abstract
Newborn screening (NBS) is a successful public health initiative that effectively identifies pre-symptomatic neonates so that treatment can be initiated before the onset of irreversible morbidity and mortality. Legislation passed in 2008 has supported a system of state screening programs, educational resources, and an evidence-based review process to add conditions to a recommended universal newborn screening panel (RUSP). The Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), NIH, has promoted NBS research to advance legislative goals by supporting research that will uncover fundamental mechanisms of disease, develop treatments for NBS disorders, and promote pilot studies to test implementation of new conditions. NICHD's partnerships with other federal agencies have contributed to activities that support nominations of new conditions to the RUSP. The NIH's Newborn Sequencing In Genomic Medicine and Public Health (NSIGHT) initiative funded research projects that considered how genomic sequencing could be integrated into NBS and its ethical ramifications. Recently, the workshop, "Gene Targeted Therapies: Early Diagnosis and Equitable Delivery," has explored the possibility of expanding NBS to include genetic diagnosis and precision, gene-based therapies. Although hurdles remain to realize such a vision, broad engagement of multiple stakeholders is essential to advance genomic medicine within NBS.
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Affiliation(s)
- Mollie A. Minear
- Intellectual and Developmental Disabilities Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
| | - Megan N. Phillips
- Intellectual and Developmental Disabilities Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
- Present address: Allen Institute for Brain Science, Seattle, WA, USA
| | - Alice Kau
- Intellectual and Developmental Disabilities Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
| | - Melissa A. Parisi
- Intellectual and Developmental Disabilities Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
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Veldman A, Kiewiet MBG, Heiner-Fokkema MR, Nelen MR, Sinke RJ, Sikkema-Raddatz B, Voorhoeve E, Westra D, Dollé MET, Schielen PCJI, van Spronsen FJ. Towards Next-Generation Sequencing (NGS)-Based Newborn Screening: A Technical Study to Prepare for the Challenges Ahead. Int J Neonatal Screen 2022; 8:ijns8010017. [PMID: 35323196 PMCID: PMC8949100 DOI: 10.3390/ijns8010017] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 01/28/2022] [Accepted: 02/08/2022] [Indexed: 01/27/2023] Open
Abstract
Newborn screening (NBS) aims to identify neonates with severe conditions for whom immediate treatment is required. Currently, a biochemistry-first approach is used to identify these disorders, which are predominantly inherited meta1bolic disorders (IMD). Next-generation sequencing (NGS) is expected to have some advantages over the current approach, for example the ability to detect IMDs that meet all screening criteria but lack an identifiable biochemical footprint. We have now designed a technical study to explore the use of NGS techniques as a first-tier approach in NBS. Here, we describe the aim and set-up of the NGS-first for the NBS (NGSf4NBS) project, which will proceed in three steps. In Step 1, we will identify IMDs eligible for NGS-first testing, based on treatability. In Step 2, we will investigate the feasibility, limitations and comparability of different technical NGS approaches and analysis workflows for NBS, eventually aiming to develop a rapid NGS-based workflow. Finally, in Step 3, we will prepare for the incorporation of this workflow into the existing Dutch NBS program and propose a protocol for referral of a child after a positive NGS test result. The results of this study will be the basis for an additional analytical route within NBS that will be further studied for its applicability within the NBS program, e.g., regarding the ethical, legal, financial and social implications.
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Affiliation(s)
- Abigail Veldman
- Division of Metabolic Diseases, Beatrix Children’s Hospital, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, The Netherlands;
- Correspondence: (A.V.); (M.B.G.K.)
| | - Mensiena B. G. Kiewiet
- Division of Metabolic Diseases, Beatrix Children’s Hospital, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, The Netherlands;
- Department of Genetics, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, The Netherlands; (R.J.S.); (B.S.-R.)
- Correspondence: (A.V.); (M.B.G.K.)
| | - Margaretha Rebecca Heiner-Fokkema
- Department of Laboratory Medicine, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, The Netherlands;
| | - Marcel R. Nelen
- Department of Human Genetics, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands; (M.R.N.); (D.W.)
| | - Richard J. Sinke
- Department of Genetics, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, The Netherlands; (R.J.S.); (B.S.-R.)
| | - Birgit Sikkema-Raddatz
- Department of Genetics, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, The Netherlands; (R.J.S.); (B.S.-R.)
| | - Els Voorhoeve
- Centre for Health Protection, National Institute for Public Health and the Environment, 3720 BA Bilthoven, The Netherlands; (E.V.); (M.E.T.D.)
| | - Dineke Westra
- Department of Human Genetics, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands; (M.R.N.); (D.W.)
| | - Martijn E. T. Dollé
- Centre for Health Protection, National Institute for Public Health and the Environment, 3720 BA Bilthoven, The Netherlands; (E.V.); (M.E.T.D.)
| | - Peter C. J. I. Schielen
- Centre for Population Screening, National Institute for Public Health and the Environment, 3720 BA Bilthoven, The Netherlands;
| | - Francjan J. van Spronsen
- Division of Metabolic Diseases, Beatrix Children’s Hospital, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, The Netherlands;
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Zhou W, Cai H, Li H, Ji Z, Gu M. Quantification of Differential Metabolites in Dried Blood Spots Using Second-Tier Testing for SCADD/IBDD Disorders Based on Large-Scale Newborn Screening in a Chinese Population. Front Pediatr 2021; 9:757424. [PMID: 34869113 PMCID: PMC8639864 DOI: 10.3389/fped.2021.757424] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 10/20/2021] [Indexed: 12/14/2022] Open
Abstract
Background: Although newborn screening (NBS) for metabolic defects using the marker butyl carnitine (C4) combined with the C4-to-acetylcarnitine ratio is adequate, the incorporation of novel parameters may improve differential testing for these disorders without compromising sensitivity. Methods: Analytical and clinical performance was evaluated by MS/MS using 237 initially positive neonatal samples between March 2019 and March 2020 at the Newborn Screening Center of Xuzhou Maternity and Child Health Care Hospital. Additionally, second-tier testing by ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) combined with the quantification of ethylmalonate (EMA) or isobutyryl-glycine (IBG) in dried blood spots (DBSs) was performed to reduce the false-positive rate. Results: We reviewed initial MS/MS data for DBSs from 469,730 neonates, and a second-tier test was performed using 237 samples that exceeded the C4 concentration cutoff value. Eleven variants of the ACADS gene were identified, with c.1031A>G (p.E344G) being the most common. Fifteen ACAD8 mutations were identified in seven patients, and Swiss modeling and amino acid conservation analyses were conducted for the novel variants. Based on a retrospective analysis of EMA and IBG, the application of second-tier tests before the release of neonatal screening results reduced referrals by over 91.89% and improved the positive predictive value (PPV) for short-chain acyl-CoA dehydrogenase deficiency/isobutyryl-CoA dehydrogenase deficiency (SCADD/IBDD) screening. Conclusion: A screening algorithm including EMA/IBG improves target differential testing for NBS and may eliminate unnecessary referrals while maintaining 100% sensitivity. Second-tier screening using UPLC-MS/MS as a rapid and convenient supplemental DNA sequencing method may be beneficial for differential detection.
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Affiliation(s)
- Wei Zhou
- Newborn Screening Center, The Affiliated Xuzhou Maternity and Child Health Care Hospital of Xuzhou Medical University, Xuzhou, China.,Research Center for Biochemistry and Molecular Biology and Jiangsu Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical University, Xuzhou, China
| | - Heng Cai
- Pharmacology College, Xuzhou Medical University, Xuzhou, China
| | - Huizhong Li
- Newborn Screening Center, The Affiliated Xuzhou Maternity and Child Health Care Hospital of Xuzhou Medical University, Xuzhou, China
| | - Zhe Ji
- The First Clinical College, Xuzhou Medical University, Xuzhou, China
| | - Maosheng Gu
- Newborn Screening Center, The Affiliated Xuzhou Maternity and Child Health Care Hospital of Xuzhou Medical University, Xuzhou, China
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