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Ahmed S, Cai L, Akbar F, Siddiqui A, DeBerardinis RJ, Ni M, Vu H, Afroze B. Evaluation of the clinical, biochemical, and molecular spectrum of Cobalamin C (CblC) defect in 33 patients from Pakistan. Scand J Clin Lab Invest 2024:1-7. [PMID: 39225018 DOI: 10.1080/00365513.2024.2394983] [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: 05/18/2024] [Revised: 08/13/2024] [Accepted: 08/18/2024] [Indexed: 09/04/2024]
Abstract
BACKGROUND Cobalamin C is the most common inborn error of intracellular cobalamin metabolism caused by biallelic pathogenic variants in the MMACHC gene, leading to impaired conversion of dietary vitamin B12 into its two metabolically active forms, methylcobalamin and adenosylcobalamin. Biochemical hallmarks are elevated plasma total homocysteine (HCYs) and low methionine accompanied by methylmalonic aciduria. This study aimed to evaluate the clinical, biochemical, and molecular analysis of Pakistani patients with CblC defect. METHODS Medical charts, urine organic acid (UOA) chromatograms, plasma amino acid levels, plasma tHcy and MMACHC gene results of patients presenting at the Biochemical Genetics Clinic, AKUH from 2013-2021 were reviewed. Details were collected on a pre-structured questionnaire. SPSS 22 was used for data analysis. RESULTS CblC was found in 33 cases (Male:Female 19:14). The median age of symptoms onset and diagnosis were 300 (IQR:135-1800) and 1380 (IQR: 240-2730) days. The most common clinical features were cognitive impairment (n = 29), seizures (n = 23), motor developmental delay (n = 20), hypotonia (n = 17), and sparse/hypopigmented scalp hair (n = 16). The MMACHC gene sequencing revealed homozygous pathogenic variant c.394C > T, (p.Arg132*) in 32 patients, whereas c.609G > A, (p.TRP203*) in one patient whose ancestors had settled in Pakistan from China decades ago. The median age of treatment initiation was 1530 (IQR: 240-2790). The median pre-treatment HCYs levels were 134 (IQR:87.2-155.5) compared to post-treatment levels of 33.3 (IQR: 27.3-44.95) umol/L. CONCLUSIONS Thirty-three cases of CblC defect from a single center underscores a significant number of the disorder within Pakistan. Late diagnosis emphasizes the need for increased clinical awareness and adequate diagnostic facilities.
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Affiliation(s)
- Sibtain Ahmed
- Section of Chemical Pathology, Department of Pathology and Laboratory Medicine, Aga Khan University
| | - Ling Cai
- Quantitative Biomedical Research Center, Peter O'Donnell School of Public Health, UT Southwestern, TX, USA
| | - Fizza Akbar
- Department of Paediatrics & Child Health, Aga Khan University Hospital, Karachi
| | - Ayra Siddiqui
- Medical College, Aga Khan University Hospital, Karachi
| | - Ralph J DeBerardinis
- Children's Medical Center Research Institute at UT Southwestern, Texas, USA
- Howard Hughes Medical Institute, UT Southwestern, Texas, USA
| | - Min Ni
- Children's Medical Center Research Institute at UT Southwestern, Texas, USA
| | - Hieu Vu
- Children's Medical Center Research Institute at UT Southwestern, Texas, USA
| | - Bushra Afroze
- Quantitative Biomedical Research Center, Peter O'Donnell School of Public Health, UT Southwestern, TX, USA
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Yverneau M, Leroux S, Imbard A, Gleich F, Arion A, Moreau C, Nassogne MC, Szymanowski M, Tardieu M, Touati G, Bueno M, Chapman KA, Chien YH, Huemer M, Ješina P, Janssen MCH, Kölker S, Kožich V, Lavigne C, Lund AM, Mochel F, Morris A, Pons MR, Porras-Hurtado GL, Benoist JF, Damaj L, Schiff M. Influence of early identification and therapy on long-term outcomes in early-onset MTHFR deficiency. J Inherit Metab Dis 2022; 45:848-861. [PMID: 35460084 DOI: 10.1002/jimd.12504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 04/12/2022] [Accepted: 04/21/2022] [Indexed: 11/08/2022]
Abstract
MTHFR deficiency is a severe inborn error of metabolism leading to impairment of the remethylation of homocysteine to methionine. Neonatal and early-onset patients mostly exhibit a life-threatening acute neurologic deterioration. Furthermore, data on early-onset patients' long-term outcomes are scarce. The aims of this study were (1) to study and describe the clinical and laboratory parameters of early-onset MTHFR-deficient patients (i.e., ≤3 months of age) and (2) to identify predictive factors for severe neurodevelopmental outcomes in a cohort with early and late onset MTHFR-deficient patients. To this end, we conducted a retrospective, multicentric, international cohort study on 72 patients with MTHFR deficiency from 32 international metabolic centres. Characteristics of the 32 patients with early-onset MTHFR deficiency were described at time of diagnosis and at the last follow-up visit. Logistic regression analysis was used to identify predictive factors of severe neurodevelopmental outcome in a broader set of patients with early and non-early-onset MTHFR deficiency. The majority of early-onset MTHFR-deficient patients (n = 32) exhibited neurologic symptoms (76%) and feeding difficulties (70%) at time of diagnosis. At the last follow-up visit (median follow-up time of 8.1 years), 76% of treated early-onset patients (n = 29) exhibited a severe neurodevelopmental outcome. Among the whole study population of 64 patients, pre-symptomatic diagnosis was independently associated with a significantly better neurodevelopmental outcome (adjusted OR 0.004, [0.002-0.232]; p = 0.003). This study provides evidence for benefits of pre-symptomatic diagnosis and appropriate therapeutic management, highlighting the need for systematic newborn screening for MTHFR deficiency and pre-symptomatic treatment that may improve outcome.
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Affiliation(s)
- Mathilde Yverneau
- Department of Child and Adolescent Medicine, Rennes Hospital, Rennes, France
| | - Stéphanie Leroux
- Department of Child and Adolescent Medicine, Rennes Hospital, Rennes, France
| | - Apolline Imbard
- Biochemistry Laboratory, Robert Debré Hospital, APHP, Paris, France
- Department of Pediatrics, Reference Center for Inborn Error of Metabolism, Necker and Robert-Debré Hospital, APHP, Université Paris Cité, Paris, France
- LYPSIS, Université Paris-Saclay, Châtenay-Malabry, France
| | - Florian Gleich
- Division of Child Neurology and Metabolic Medicine, Center for Child and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Alina Arion
- Department of Pediatrics, Caen Hospital, Caen, France
| | | | - Marie-Cécile Nassogne
- Pediatric Neurology Unit, Cliniques Universitaires Saint-Luc, UCLouvain, Brussels, Belgium
| | - Marie Szymanowski
- Department of Pediatrics, Estaing Hospital, Clermont-Ferrand, France
| | | | - Guy Touati
- Department of Pediatrics, Reference Center for Inborn Error of Metabolism, Toulouse Hospital, Toulouse, France
| | - María Bueno
- Hospital Universitario Virgen del Rocío, Sevilla, Spain
| | - Kimberly A Chapman
- Section of Genetics and Metabolism, Children's National Health System, Washington, District of Columbia, USA
| | - Yin-Hsiu Chien
- Department of Pediatrics, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Martina Huemer
- Division of Metabolism and Children's Research Center, University Children's Hospital, Zürich, Switzerland
- Department of Paediatrics, Landeskrankenhaus Bregenz, Bregenz, Austria
| | - Pavel Ješina
- Department of Pediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, General University Hospital, Charles University, Prague, Czech Republic
| | - Mirian C H Janssen
- Department of Internal Medicine, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Stefan Kölker
- Division of Child Neurology and Metabolic Medicine, Center for Child and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Viktor Kožich
- Department of Pediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, General University Hospital, Charles University, Prague, Czech Republic
| | - Christian Lavigne
- Department of Internal Medicine, Angers University Hospital, Angers, France
| | - Allan Meldgaard Lund
- Departments of Paediatrics and Clinical Genetics, Centre for Inherited Metabolic Diseases, Copenhagen University Hospital, Copenhagen, Denmark
| | - Fanny Mochel
- Department of Genetics, AP-HP, Pitié-Salpêtrière University Hospital, Paris, France
| | - Andrew Morris
- Willink Metabolic Unit, Manchester Centre for Genomic Medicine, Manchester University Hospitals NHS Foundation Trust, Manchester
- Alder Hey Children's Hospital, Liverpool, UK
| | | | | | - Jean-François Benoist
- Biochemistry Laboratory, Robert Debré Hospital, APHP, Paris, France
- Department of Pediatrics, Reference Center for Inborn Error of Metabolism, Necker and Robert-Debré Hospital, APHP, Université Paris Cité, Paris, France
- LYPSIS, Université Paris-Saclay, Châtenay-Malabry, France
| | - Léna Damaj
- Department of Pediatrics, Competence Center of Inherited Metabolic Disorders, Rennes Hospital, Rennes, France
| | - Manuel Schiff
- Department of Pediatrics, Reference Center for Inborn Error of Metabolism, Necker and Robert-Debré Hospital, APHP, Université Paris Cité, Paris, France
- Inserm UMR_S1163, Institut Imagine, Paris, France
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3
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Kripps KA, Sremba L, Larson AA, Van Hove JLK, Nguyen H, Wright EL, Mirsky DM, Watkins D, Rosenblatt DS, Ketteridge D, Berry SA, McCandless SE, Baker PR. Methionine synthase deficiency: Variable clinical presentation and benefit of early diagnosis and treatment. J Inherit Metab Dis 2022; 45:157-168. [PMID: 34625984 DOI: 10.1002/jimd.12448] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 10/05/2021] [Accepted: 10/06/2021] [Indexed: 11/06/2022]
Abstract
Methionine synthase deficiency (cblG complementation group) is a rare inborn error of metabolism affecting the homocysteine re-methylation pathway. It leads to a biochemical phenotype of hyperhomocysteinemia and hypomethioninemia. The clinical presentation of cblG is variable, ranging from seizures, encephalopathy, macrocytic anemia, hypotonia, and feeding difficulties in the neonatal period to onset of psychiatric symptoms or acute neurologic changes in adolescence or adulthood. Given the variable and nonspecific symptoms seen in cblG, the diagnosis of affected patients is often delayed. Medical management of cblG includes the use of hydroxocobalamin, betaine, folinic acid, and in some cases methionine supplementation. Treatment has been shown to lead to improvement in the biochemical profile of affected patients, with lowering of total homocysteine levels and increasing methionine levels. However, the published literature contains differing conclusions on whether treatment is effective in changing the natural history of the disease. Herein, we present five patients with cblG who have shown substantial clinical benefit from treatment with objective improvement in their neurologic outcomes. We demonstrate more favorable outcomes in our patients who were treated early in life, especially those who were treated before neurologic symptoms manifested. Given improved outcomes from treatment of presymptomatic patients, cblG warrants inclusion in newborn screening.
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Affiliation(s)
- Kimberly A Kripps
- Section of Genetics and Metabolism, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, Oregon, USA
| | - Leighann Sremba
- Section of Genetics and Metabolism, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Austin A Larson
- Section of Genetics and Metabolism, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Johan L K Van Hove
- Section of Genetics and Metabolism, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Hoanh Nguyen
- Section of Genetics and Metabolism, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Erica L Wright
- Section of Genetics and Metabolism, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - David M Mirsky
- Department of Radiology, University of Colorado, and Children's Hospital Colorado, Aurora, Colorado, USA
| | - David Watkins
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - David S Rosenblatt
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - David Ketteridge
- Department of Genetics and Molecular Pathology, Women's and Children's Hospital, Adelaide, South Australia, Australia
| | - Susan A Berry
- Department of Pediatrics, Division of Genetics and Metabolism, University of Minnesota, Minneapolis, Minnesota, USA
| | - Shawn E McCandless
- Section of Genetics and Metabolism, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Peter R Baker
- Section of Genetics and Metabolism, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
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4
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Amin YK. Single-nucleotide polymorphisms in MTHFR gene related to recurrent abortion. APPLIED NANOSCIENCE 2021. [DOI: 10.1007/s13204-021-01959-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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5
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Kagawa R, Tajima G, Maeda T, Sakura F, Nakamura-Utsunomiya A, Hara K, Nishimura Y, Yuasa M, Shigematsu Y, Tanaka H, Fujihara S, Yoshii C, Okada S. Pilot Study on Neonatal Screening for Methylmalonic Acidemia Caused by Defects in the Adenosylcobalamin Synthesis Pathway and Homocystinuria Caused by Defects in Homocysteine Remethylation. Int J Neonatal Screen 2021; 7:ijns7030039. [PMID: 34287232 PMCID: PMC8293178 DOI: 10.3390/ijns7030039] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 06/26/2021] [Accepted: 07/05/2021] [Indexed: 11/16/2022] Open
Abstract
Neonatal screening (NS) for methylmalonic acidemia uses propionylcarnitine (C3) as a primary index, which is insufficiently sensitive at detecting methylmalonic acidemia caused by defects in the adenosylcobalamin synthesis pathway. Moreover, homocystinuria from cystathionine β-synthase deficiency is screened by detecting hypermethioninemia, but methionine levels decrease in homocystinuria caused by defects in homocysteine remethylation. To establish NS detection of methylmalonic acidemia and homocystinuria of these subtypes, we evaluated the utility of indices (1) C3 ≥ 3.6 μmol/L and C3/acetylcarnitine (C2) ≥ 0.23, (2) C3/methionine ≥ 0.25, and (3) methionine < 10 μmol/L, by retrospectively applying them to NS data of 59,207 newborns. We found positive results in 116 subjects for index (1), 37 for (2), and 15 for (3). Second-tier tests revealed that for index 1, methylmalonate (MMA) was elevated in two cases, and MMA and total homocysteine (tHcy) were elevated in two cases; for index 2 that MMA was elevated in one case; and for index 3 that tHcy was elevated in one case. Though data were anonymized, two cases identified by index 1 had been diagnosed with maternal vitamin B12 deficiency during NS. Methylene tetrahydrofolate reductase deficiency was confirmed for the case identified by index 3, which was examined because an elder sibling was affected by the same disease. Based on these data, a prospective NS study is underway.
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Affiliation(s)
- Reiko Kagawa
- Department of Pediatrics, Hiroshima University Graduate School of Biomedical and Health Sciences, Minami-ku, Hiroshima 734-8551, Japan; (R.K.); (F.S.); (S.O.)
| | - Go Tajima
- Department of Pediatrics, Hiroshima University Graduate School of Biomedical and Health Sciences, Minami-ku, Hiroshima 734-8551, Japan; (R.K.); (F.S.); (S.O.)
- Division of Neonatal Screening, Research Institute, National Center for Child Health and Development, Setagaya-ku, Tokyo 157-8535, Japan;
- Correspondence: ; Tel.: +81-3-5494-7133
| | - Takako Maeda
- Division of Neonatal Screening, Research Institute, National Center for Child Health and Development, Setagaya-ku, Tokyo 157-8535, Japan;
| | - Fumiaki Sakura
- Department of Pediatrics, Hiroshima University Graduate School of Biomedical and Health Sciences, Minami-ku, Hiroshima 734-8551, Japan; (R.K.); (F.S.); (S.O.)
| | | | - Keiichi Hara
- Department of Pediatrics, National Hospital Organization Kure Medical Center and Chugoku Cancete Center, Kure 737-0023, Japan;
| | - Yutaka Nishimura
- Department of General Perinatology, Hiroshima City Hiroshima Citizens Hospital, Naka-Ku, Hiroshima 730-8518, Japan;
| | - Miori Yuasa
- Department of Pediatrics, Faculty of Medical Sciences, University of Fukui, Eiheiji-cho, Fukui 910-1193, Japan; (M.Y.); (Y.S.)
| | - Yosuke Shigematsu
- Department of Pediatrics, Faculty of Medical Sciences, University of Fukui, Eiheiji-cho, Fukui 910-1193, Japan; (M.Y.); (Y.S.)
| | - Hiromi Tanaka
- Hiroshima City Medical Association Clinical Laboratory, Naka-ku, Hiroshima 730-8611, Japan; (H.T.); (S.F.); (C.Y.)
| | - Saki Fujihara
- Hiroshima City Medical Association Clinical Laboratory, Naka-ku, Hiroshima 730-8611, Japan; (H.T.); (S.F.); (C.Y.)
| | - Chiyoko Yoshii
- Hiroshima City Medical Association Clinical Laboratory, Naka-ku, Hiroshima 730-8611, Japan; (H.T.); (S.F.); (C.Y.)
| | - Satoshi Okada
- Department of Pediatrics, Hiroshima University Graduate School of Biomedical and Health Sciences, Minami-ku, Hiroshima 734-8551, Japan; (R.K.); (F.S.); (S.O.)
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6
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Almannai M, Al Mahmoud RA, Mekki M, El-Hattab AW. Metabolic Seizures. Front Neurol 2021; 12:640371. [PMID: 34295297 PMCID: PMC8290068 DOI: 10.3389/fneur.2021.640371] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 05/21/2021] [Indexed: 12/13/2022] Open
Abstract
Metabolic diseases should always be considered when evaluating children presenting with seizures. This is because many metabolic disorders are potentially treatable and seizure control can be achieved when these diseases are appropriately treated. Seizures caused by underlying metabolic diseases (metabolic seizures) should be particularly considered in unexplained neonatal seizures, refractory seizures, seizures related to fasting or food intake, seizures associated with other systemic or neurologic features, parental consanguinity, and family history of epilepsy. Metabolic seizures can be caused by various amino acids metabolic disorders, disorders of energy metabolism, cofactor-related metabolic diseases, purine and pyrimidine metabolic diseases, congenital disorders of glycosylation, and lysosomal and peroxisomal disorders. Diagnosing metabolic seizures without delay is essential because the immediate initiation of appropriate therapy for many metabolic diseases can prevent or minimize complications.
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Affiliation(s)
- Mohammed Almannai
- Section of Medical Genetics, Children's Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Rabah A Al Mahmoud
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates.,Department of Pediatrics, University Hospital Sharjah, Sharjah, United Arab Emirates
| | - Mohammed Mekki
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates.,Department of Pediatrics, Al Qassimi Women's and Children's Hospital, Sharjah, United Arab Emirates
| | - Ayman W El-Hattab
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates.,Clinical Genetics, University Hospital Sharjah, Sharjah, United Arab Emirates
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7
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The 1316T>C missenses mutation in MTHFR contributes to MTHFR deficiency by targeting MTHFR to proteasome degradation. Aging (Albany NY) 2020; 13:1176-1185. [PMID: 33290257 PMCID: PMC7834980 DOI: 10.18632/aging.202256] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Accepted: 10/27/2020] [Indexed: 11/25/2022]
Abstract
5,10-methylenetetrahydrofolate reductase (MTHFR) deficiency is a rare hereditary disease characterized by defects in folate and homocysteine metabolism. Individuals with inherited MTHFR gene mutations have a higher tendency to develop neurodegeneration disease as Alzheimer’ disease and atherosclerosis. MTHFR is a rate-limiting enzyme catalyzing folate production, various SNPs/mutations in the MTHFR gene have been correlated to MTHFR deficiency. However, the molecular mechanisms underpinning the pathogenic effects of these SNPs/mutations have not been clearly understood. In the present study, we reported a severe MTHFR deficiency patient with late-onset motor dysfunction and sequenced MTHFR gene exons of the family. The patient carries an MD-associating SNP (rs748289202) in one MTHFR allele and the rs545086633 SNP with unknown disease relevance in the other. The rs545086633 SNP (p.Leu439Pro) results in an L439P substitution in MTHFR protein, and drastically decreases mutant protein expression by promoting proteasomal degradation. L439 in MTHFR is highly conserved in vertebrates. Our study demonstrated that p.Leu439Pro in MTHFR is the first mutation causing significant intracellular defects of MTHFR, and rs545086633 should be examined for the in-depth diagnosis and treatment of MD.
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González-Irazabal Y, Hernandez de Abajo G, Martínez-Morillo E. Identifying and overcoming barriers to harmonize newborn screening programs through consensus strategies. Crit Rev Clin Lab Sci 2020; 58:29-48. [PMID: 32692303 DOI: 10.1080/10408363.2020.1781778] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The benefits of newborn screening (NBS) programs have been widely demonstrated after more than 50 years since first established. NBS enables the detection of the disease before the child shows clinical symptoms, allowing clinicians to act early and facilitating appropriate interventions to prevent or improve adverse outcomes. Delay or lack of medical intervention in these infants may lead to developmental delay, severe disability, or premature death. NBS programs have grown exponentially both in the number of diseases screened and in complexity, creating controversy. New technological advances, as well as the emergence of new therapies that require early disease detection, have allowed for the inclusion of new diseases in NBS screening programs. However, different countries and even different regions have in turn adopted very diverse strategies and diagnostic algorithms when it comes to NBS. There are many factors responsible for these differences, such as the health care system, available funds, local politics, professional groups, and others that depend on the position taken by policymakers. These differences in NBS have led to discrepancies in detection opportunities between countries or regions, which has led to many varied attempts to harmonize NBS programs but not all have been equally satisfactory. Some countries have achieved good results, but always within their borders. Therefore, there are still many differences between NBS programs at the international level that must be overcome. These advances have also brought considerable uncertainty regarding ethical aspects and balance between benefits and harms. For this reason, and so that the situation of disparity in the global NBS programs can be minimized, health authorities must work to develop uniform criteria for decision-making and to take a further step toward harmonization. To do so, it is necessary to identify the crucial factors that lead to the adoption of different NBS programs worldwide, in order to analyze their influence and find ways to overcome them.
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Gavrilov DK, Piazza AL, Pino G, Turgeon C, Matern D, Oglesbee D, Raymond K, Tortorelli S, Rinaldo P. The Combined Impact of CLIR Post-Analytical Tools and Second Tier Testing on the Performance of Newborn Screening for Disorders of Propionate, Methionine, and Cobalamin Metabolism. Int J Neonatal Screen 2020; 6:33. [PMID: 33073028 PMCID: PMC7423003 DOI: 10.3390/ijns6020033] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 04/07/2020] [Indexed: 12/13/2022] Open
Abstract
The expansion of the recommend uniform screening panel to include more than 50 primary and secondary target conditions has resulted in a substantial increase of false positive results. As an alternative to subjective manipulation of cutoff values and overutilization of molecular testing, here we describe the performance outcome of an algorithm for disorders of methionine, cobalamin, and propionate metabolism that includes: (1) first tier screening inclusive of the broadest available spectrum of markers measured by tandem mass spectrometry; (2) integration of all results into a score of likelihood of disease for each target condition calculated by post-analytical interpretive tools created byCollaborative Laboratory Integrated Reports (CLIR), a multivariate pattern recognition software; and (3) further evaluation of abnormal scores by a second tier test measuring homocysteine, methylmalonic acid, and methylcitric acid. This approach can consistently reduce false positive rates to a <0.01% level, which is the threshold of precision newborn screening. We postulate that broader adoption of this algorithm could lead to substantial savings in health care expenditures. More importantly, it could prevent the stress and anxiety experienced by many families when faced with an abnormal newborn screening result that is later resolved as a false positive outcome.
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Affiliation(s)
- Dimitar K Gavrilov
- Biochemical Genetics Laboratory, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, USA; (A.L.P.); (G.P.); (C.T.); (D.M.); (D.O.); (K.R.); (S.T.); (P.R.)
| | - Amy L Piazza
- Biochemical Genetics Laboratory, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, USA; (A.L.P.); (G.P.); (C.T.); (D.M.); (D.O.); (K.R.); (S.T.); (P.R.)
| | - Gisele Pino
- Biochemical Genetics Laboratory, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, USA; (A.L.P.); (G.P.); (C.T.); (D.M.); (D.O.); (K.R.); (S.T.); (P.R.)
| | - Coleman Turgeon
- Biochemical Genetics Laboratory, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, USA; (A.L.P.); (G.P.); (C.T.); (D.M.); (D.O.); (K.R.); (S.T.); (P.R.)
| | - Dietrich Matern
- Biochemical Genetics Laboratory, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, USA; (A.L.P.); (G.P.); (C.T.); (D.M.); (D.O.); (K.R.); (S.T.); (P.R.)
| | - Devin Oglesbee
- Biochemical Genetics Laboratory, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, USA; (A.L.P.); (G.P.); (C.T.); (D.M.); (D.O.); (K.R.); (S.T.); (P.R.)
| | - Kimiyo Raymond
- Biochemical Genetics Laboratory, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, USA; (A.L.P.); (G.P.); (C.T.); (D.M.); (D.O.); (K.R.); (S.T.); (P.R.)
| | - Silvia Tortorelli
- Biochemical Genetics Laboratory, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, USA; (A.L.P.); (G.P.); (C.T.); (D.M.); (D.O.); (K.R.); (S.T.); (P.R.)
| | - Piero Rinaldo
- Biochemical Genetics Laboratory, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, USA; (A.L.P.); (G.P.); (C.T.); (D.M.); (D.O.); (K.R.); (S.T.); (P.R.)
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10
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Wang B, Zhang Q, Gao A, Wang Q, Ma J, Li H, Wang T. New Ratios for Performance Improvement for Identifying Acyl-CoA Dehydrogenase Deficiencies in Expanded Newborn Screening: A Retrospective Study. Front Genet 2019; 10:811. [PMID: 31620161 PMCID: PMC6759686 DOI: 10.3389/fgene.2019.00811] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 08/06/2019] [Indexed: 12/17/2022] Open
Abstract
Some success in identifying acyl-CoA dehydrogenase (ACAD) deficiencies before they are symptomatic has been achieved through tandem mass spectrometry. However, there has been several challenges that need to be confronted, including excess false positives, the occasional false negatives and indicators selection. To select ideal indicators and evaluate their performance for identifying ACAD deficiencies, data from 352,119 newborn babies, containing 20 cases, were used in this retrospective study. A total of three new ratios, C4/C5DC+C6-OH, C8/C14:1, and C14:1/C16-OH, were selected from 43 metabolites. Around 903 ratios derived from pairwise combinations of all metabolites via multivariate logistic regression analysis were used. In the current study, the regression analysis was performed to identify short chain acyl-CoA dehydrogenase (SCAD) deficiency, medium chain acyl-CoA dehydrogenase (MCAD) deficiency, and very long chain acyl-CoA dehydrogenase (VLCAD) deficiency. In both model-building and testing data, the C4/C5DC+C6-OH, C8/C14:1 and C14:1/C16-OH were found to be better indicators for SCAD, MCAD and VLCAD deficiencies, respectively, compared to [C4, (C4, C4/C2)], [C8, (C6, C8, C8/C2, C4DC+C5-OH/C8:1)], and [C14:1, (C14:1, C14:1/C16, C14:1/C2)], respectively. In addition, 22 mutations, including 5 novel mutations and 17 reported mutations, in ACADS, ACADM, and ACADL genes were detected in 20 infants with ACAD deficiency by using high-thorough sequencing based on target capture. The pathogenic mutations of c.1031A > G in ACADS, c.449_452delCTGA in ACADM and c.1349G > A in ACADL were found to be hot spots in Suzhou patients with SCAD, MCAD, and VLCAD, respectively. In conclusion, we had identified three new ratios that could improve the performance for ACAD deficiencies compared to the used indicators. We considered to utilize C4/C5DC+C6-OH, C8/C14:1, and C14:1/C16-OH as primary indicators for SCAD, MCAD, and VLCAD deficiency, respectively, in further expanded newborn screening practice. In addition, the spectrum of mutations in Suzhou population enriches genetic data of Chinese patients with one of ACAD deficiencies.
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Affiliation(s)
- Benjing Wang
- Newborn Screening Laboratory, Center for Reproduction and Genetics, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, China
| | - Qin Zhang
- Newborn Screening Laboratory, Center for Reproduction and Genetics, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, China
| | - Ang Gao
- Genetic Clinic, Center for Reproduction and Genetics, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, China
| | - Qi Wang
- Newborn Screening Laboratory, Center for Reproduction and Genetics, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, China
| | - Jun Ma
- Newborn Screening Laboratory, Center for Reproduction and Genetics, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, China
| | - Hong Li
- Infertility Clinic, Center for Reproduction and Genetics, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, China
| | - Ting Wang
- Newborn Screening Laboratory, Center for Reproduction and Genetics, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, China
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11
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Liu Y, Kang L, Li D, Jin Y, Song J, Li H, Wang J, Yang Y. Patients with cobalamin G or J defect missed by the current newborn screening program: diagnosis and novel mutations. J Hum Genet 2019; 64:305-312. [PMID: 30651581 DOI: 10.1038/s10038-018-0557-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 11/27/2018] [Accepted: 12/18/2018] [Indexed: 12/23/2022]
Abstract
Cobalamin G (cblG) and cobalamin J (cblJ) defects are rare disorders of cbl metabolism caused by MTR and ABCD4 mutations, respectively. Patients with atypical biochemical features can be missed by current newborn screening using tandem mass spectrometry (MS/MS), in which total homocysteine (tHCY) in dried blood spots (DBS) is not a primary biomarker. Two Chinese patients suspected of cbl defect but missed by newborn screening were studied. Using comprehensive metabolic analyses including MS/MS assay for tHCY in DBS, slightly low methionine in Patient 1, methymalonic aciduria in Patient 2, and homocysteinemia in both patients were detected, and DBS tHCY of two patients were obviously elevated (59.22 μmol/L, 17.75 μmol/L) compared to 140 healthy controls (2.5th-97.5th percentile, 1.05-8.22 μmol/L). Utilizing whole-exome sequencing, we found two novel MTR variants c.871C>T (p.Pro291Ser) and c.1771C>T (p.Arg591*) in Patient 1, and a ABCD4 homozygous variant c.423C>G (p.Asn141Lys) in Patient 2. Our study identified the first cblG patient and cblJ patient in mainland China, and highlighted comprehensive metabolic analyses and genetic tests in patients suspected of cbl defects. It also indicated that supplementary MS/MS assay for tHCY in DBS may be practical for early diagnosis of homocysteinemia, without repeated blood sampling.
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Affiliation(s)
- Yi Liu
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China
| | - Lulu Kang
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China
| | - Dongxiao Li
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China
| | - Ying Jin
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China
| | - Jinqing Song
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China
| | - Haixia Li
- Department of Clinical Laboratory, Peking University First Hospital, Beijing, 100034, China
| | - Junjuan Wang
- Zhejiang Biosan Biochemical Technologies Co., Ltd, Hangzhou, 310012, China
| | - Yanling Yang
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China.
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12
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Keller R, Chrastina P, Pavlíková M, Gouveia S, Ribes A, Kölker S, Blom HJ, Baumgartner MR, Bártl J, Dionisi-Vici C, Gleich F, Morris AA, Kožich V, Huemer M, Barić I, Ben-Omran T, Blasco-Alonso J, Bueno Delgado MA, Carducci C, Cassanello M, Cerone R, Couce ML, Crushell E, Delgado Pecellin C, Dulin E, Espada M, Ferino G, Fingerhut R, Garcia Jimenez I, Gonzalez Gallego I, González-Irazabal Y, Gramer G, Juan Fita MJ, Karg E, Klein J, Konstantopoulou V, la Marca G, Leão Teles E, Leuzzi V, Lilliu F, Lopez RM, Lund AM, Mayne P, Meavilla S, Moat SJ, Okun JG, Pasquini E, Pedron-Giner CC, Racz GZ, Ruiz Gomez MA, Vilarinho L, Yahyaoui R, Zerjav Tansek M, Zetterström RH, Zeyda M. Newborn screening for homocystinurias: Recent recommendations versus current practice. J Inherit Metab Dis 2019; 42:128-139. [PMID: 30740731 DOI: 10.1002/jimd.12034] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To assess how the current practice of newborn screening (NBS) for homocystinurias compares with published recommendations. METHODS Twenty-two of 32 NBS programmes from 18 countries screened for at least one form of homocystinuria. Centres provided pseudonymised NBS data from patients with cystathionine beta-synthase deficiency (CBSD, n = 19), methionine adenosyltransferase I/III deficiency (MATI/IIID, n = 28), combined remethylation disorder (cRMD, n = 56) and isolated remethylation disorder (iRMD), including methylenetetrahydrofolate reductase deficiency (MTHFRD) (n = 8). Markers and decision limits were converted to multiples of the median (MoM) to allow comparison between centres. RESULTS NBS programmes, algorithms and decision limits varied considerably. Only nine centres used the recommended second-tier marker total homocysteine (tHcy). The median decision limits of all centres were ≥ 2.35 for high and ≤ 0.44 MoM for low methionine, ≥ 1.95 for high and ≤ 0.47 MoM for low methionine/phenylalanine, ≥ 2.54 for high propionylcarnitine and ≥ 2.78 MoM for propionylcarnitine/acetylcarnitine. These decision limits alone had a 100%, 100%, 86% and 84% sensitivity for the detection of CBSD, MATI/IIID, iRMD and cRMD, respectively, but failed to detect six individuals with cRMD. To enhance sensitivity and decrease second-tier testing costs, we further adapted these decision limits using the data of 15 000 healthy newborns. CONCLUSIONS Due to the favorable outcome of early treated patients, NBS for homocystinurias is recommended. To improve NBS, decision limits should be revised considering the population median. Relevant markers should be combined; use of the postanalytical tools offered by the CLIR project (Collaborative Laboratory Integrated Reports, which considers, for example, birth weight and gestational age) is recommended. tHcy and methylmalonic acid should be implemented as second-tier markers.
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Affiliation(s)
- Rebecca Keller
- Division of Metabolism and Children's Research Center, University Children's Hospital Zürich, Zürich, Switzerland
- radiz-Rare Disease Initiative Zürich, Clinical Research Priority Program, University of Zürich, Zürich, Switzerland
| | - Petr Chrastina
- Department of Pediatrics and Adolescent Medicine, Charles University-First Faculty of Medicine and General University Hospital, Ke Karlovu 2, 128 08 Praha 2, Czech Republic
| | - Markéta Pavlíková
- Department of Pediatrics and Adolescent Medicine, Charles University-First Faculty of Medicine and General University Hospital, Ke Karlovu 2, 128 08 Praha 2, Czech Republic
- Department of Probability and Mathematical Statistics, Charles University-Faculty of Mathematics and Physics, Prague, Czech Republic
| | - Sofía Gouveia
- Unit of Diagnosis and Treatment of Congenital Metabolic Diseases, S. Neonatology, Department of Pediatrics, Hospital Clínico Universitario de Santiago de Compostela, CIBERER, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - Antonia Ribes
- Division of Inborn Errors of Metabolism, Department of Biochemistry and Molecular Genetics, Hospital Clinic de Barcelona, CIBERER, Barcelona, Spain
| | - Stefan Kölker
- Division of Neuropaediatrics and Metabolic Medicine, Centre for Paediatric and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Henk J Blom
- Department of Internal Medicine, VU Medical Center, Amsterdam, The Netherlands
| | - Matthias R Baumgartner
- Division of Metabolism and Children's Research Center, University Children's Hospital Zürich, Zürich, Switzerland
- radiz-Rare Disease Initiative Zürich, Clinical Research Priority Program, University of Zürich, Zürich, Switzerland
| | - Josef Bártl
- Department of Pediatrics and Adolescent Medicine, Charles University-First Faculty of Medicine and General University Hospital, Ke Karlovu 2, 128 08 Praha 2, Czech Republic
| | - Carlo Dionisi-Vici
- Division of Metabolism, Bambino Gesù Children's Research Hospital, Rome, Italy
| | - Florian Gleich
- Division of Neuropaediatrics and Metabolic Medicine, Centre for Paediatric and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Andrew A Morris
- Manchester Centre for Genomic Medicine, Manchester University Hospitals NHS Trust, Manchester, UK
| | - Viktor Kožich
- Department of Pediatrics and Adolescent Medicine, Charles University-First Faculty of Medicine and General University Hospital, Ke Karlovu 2, 128 08 Praha 2, Czech Republic
| | - Martina Huemer
- Division of Metabolism and Children's Research Center, University Children's Hospital Zürich, Zürich, Switzerland
- radiz-Rare Disease Initiative Zürich, Clinical Research Priority Program, University of Zürich, Zürich, Switzerland
- Department of Paediatrics, Landeskrankenhaus Bregenz, Bregenz, Austria
| | - Ivo Barić
- School of Medicine, University Hospital Centre Zagreb and University of Zagreb, Zagreb, Croatia
| | - Tawfeq Ben-Omran
- Clinical and Metabolic Genetics, Department of Pediatrics, Hamad Medical Corporation, Doha, Qatar
| | - Javier Blasco-Alonso
- Gastroenterology and Nutrition Unit, Hospital Regional Universitario de Málaga, Málaga, Spain
| | - Maria A Bueno Delgado
- Clinical Laboratory of Metabolic Diseases and Occidental Andalucia Newborn Screening Center, Hospital Universitario Virgen del Rocío, Sevilla, Spain
| | - Claudia Carducci
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
| | - Michela Cassanello
- Laboratory for the Study of Inborn Errors of Metabolism, Istituto Giannina Gaslini, Genoa, Italy
| | - Roberto Cerone
- Regional Center for Neonatal Screening and Diagnosis of Metabolic Diseases, University Department of Pediatrics-Istituto Giannina Gaslini, Genoa, Italy
| | - Maria Luz Couce
- Unit of Diagnosis and Treatment of Congenital Metabolic Diseases, S. Neonatology, Department of Pediatrics, Hospital Clínico Universitario de Santiago de Compostela, CIBERER, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - Ellen Crushell
- National Centre for Inherited Metabolic Disorders, Temple Street Children's University Hospital, Dublin, Ireland
| | - Carmen Delgado Pecellin
- Clinical Laboratory of Metabolic Diseases and Occidental Andalucia Newborn Screening Center, Hospital Universitario Virgen del Rocío, Sevilla, Spain
| | | | - Mercedes Espada
- Clinical Chemistry Unit, Public Health Laboratory of Bilbao, Euskadi, Spain
| | - Giulio Ferino
- Regional Center for Newborn Screening, Pediatric Hospital A. Cao, AOB Brotzu, Cagliari, Italy
| | - Ralph Fingerhut
- Division of Metabolism and Children's Research Center, University Children's Hospital Zürich, Zürich, Switzerland
- Swiss Newborn Screening Laboratory, University Children's Hospital Zurich, Zurich, Switzerland
| | | | | | - Yolanda González-Irazabal
- Unidad de Metabolopatias, Servicio de Bioquímica Clínica, Hospital Universitario Miguel Servet, Zaragoza, Spain
| | - Gwendolyn Gramer
- Division of Neuropaediatrics and Metabolic Medicine, Centre for Paediatric and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Maria Jesus Juan Fita
- Sección Metabolopatías Centro de Bioquímica y Genetica, Hospital Virgen de la Arrixaca, Murcia, Spain
| | - Eszter Karg
- Department of Pediatrics, University of Szeged, Szeged, Hungary
| | - Jeanette Klein
- Newborn Screening Laboratory, Charité-University Medicine Berlin, Berlin, Germany
| | - Vassiliki Konstantopoulou
- Austrian Newborn Screening, Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
| | - Giancarlo la Marca
- Newborn Screening, Clinical Chemistry and Pharmacology Lab, A. Meyer Children's University Hospital, Florence, Italy
- Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, Italy
| | - Elisa Leão Teles
- Metabolic Unit, Department of Pediatrics, San Joao Hospital, Porto, Portugal
| | - Vincenzo Leuzzi
- Department of Human Neuroscience, Sapienza University of Rome, Rome, Italy
| | - Franco Lilliu
- Regional Center for Newborn Screening, Pediatric Hospital A. Cao, AOB Brotzu, Cagliari, Italy
| | - Rosa Maria Lopez
- Division of Inborn Errors of Metabolism, Department of Biochemistry and Molecular Genetics, Hospital Clinic de Barcelona, CIBERER, Barcelona, Spain
| | - Allan M Lund
- Centre for Inherited Metabolic Diseases, Departments of Paediatrics and Clinical Genetics, Copenhagen University Hospital, Copenhagen, Denmark
| | - Philip Mayne
- National Newborn Bloodspot Screening Laboratory, Temple Street Children's University Hospital, Dublin, Ireland
| | - Silvia Meavilla
- Gastroenterology, Hepatology and Nutrition Department, Metabolic Unit, Sant Joan de Déu Hospital, Barcelona Hospital Sant Joan de Déu, Barcelona, Spain
| | - Stuart J Moat
- Wales Newborn Screening Laboratory, Department of Medical Biochemistry, Immunology & Toxicology and School of Medicine, Cardiff University, Cardiff, Wales, UK
| | - Jürgen G Okun
- Division of Neuropaediatrics and Metabolic Medicine, Centre for Paediatric and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Elisabeta Pasquini
- Metabolic and Newborn Screening Clinical Unit, Department of Neurosciences, A. Meyer Children's University Hospital, Florence, Italy
| | | | | | - Maria Angeles Ruiz Gomez
- Clinical Lead in Metabolic Pediatric and Neurometabolic Diseases, Son Espases University Hospital, PalmaMallorca Unit, Palma de Mallorca, Spain
| | - Laura Vilarinho
- Newborn Screening, Metabolism & Genetics Unit, National Institute of Health, Porto, Portugal
| | - Raquel Yahyaoui
- Laboratory and Eastern Andalusia Newborn Screening Centre, Málaga Regional University Hospital, Institute of Biomedical Research in Málaga (IBIMA), Málaga, Spain
| | - Moja Zerjav Tansek
- Department of Diabetes, Endocrinology and Metabolic Diseases, University Children's Hospital, UMC Ljubljana, Ljubljana, Slovenia
| | - Rolf H Zetterström
- Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Maximilian Zeyda
- Austrian Newborn Screening, Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
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13
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Almannai M, El-Hattab AW. Inborn Errors of Metabolism with Seizures: Defects of Glycine and Serine Metabolism and Cofactor-Related Disorders. Pediatr Clin North Am 2018; 65:279-299. [PMID: 29502914 DOI: 10.1016/j.pcl.2017.11.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Inborn errors of metabolism (IEM) are relatively uncommon causes for seizures in children; however, they should be considered in the differential diagnosis because several IEM are potentially treatable and seizures can be resolved if appropriate treatment is initiated. Clues from clinical presentation, physical examination, laboratory tests, and brain imaging can raise the possibility of IEM. Several IEM can present with seizures, either as the main presenting finding or as a part of a more complex phenotype. These include cofactor-related disorders, glycine and serine metabolism defects, and other disorders.
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Affiliation(s)
- Mohammed Almannai
- Department of Molecular and Human Genetics, Baylor College of Medicine, Texas Children's Hospital, One Baylor Plaza, Houston, TX 77030, USA
| | - Ayman W El-Hattab
- Division of Clinical Genetics and Metabolic Disorders, Pediatrics Department, Tawam Hospital, Tawam Roundabout, Al-Ain 15258, United Arab Emirates.
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14
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Gramer G, Abdoh G, Ben-Omran T, Shahbeck N, Ali R, Mahmoud L, Fang-Hoffmann J, Hoffmann GF, Al Rifai H, Okun JG. Newborn screening for remethylation disorders and vitamin B 12 deficiency-evaluation of new strategies in cohorts from Qatar and Germany. World J Pediatr 2017; 13:136-143. [PMID: 28101774 DOI: 10.1007/s12519-017-0003-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 06/28/2016] [Indexed: 01/12/2023]
Abstract
BACKGROUND Newborn screening is a precondition for early diagnosis and successful treatment of remethylation disorders and classical homocystinuria (cystathionine-ß-synthase deficiency). Newborn screening for classical homocystinuria using total homocysteine measurement in dried blood spots has been very successfully performed for many years for newborns from Qatar. METHODS A new optimized newborn screening strategy for remethylation disorders and homocystinuria was developed and evaluated for newborns from Qatar using total homocysteine measurement as first-tier and methionine, methionine-phenylalanine-ratio and propionylcarnitine as second-tiers. Proposed cut-offs were also retrospectively evaluated in newborn screening samples of 12 patients with remethylation disorders and vitamin B12 deficiency from Qatar and Germany. RESULTS Over a 12 months period, the proposed strategy led to a decrease in the recall rate in homocysteine screening for Qatar from 1.09% to 0.68%, while allowing for additional systematic inclusion of remethylation disorders and vitamin B12 deficiency into the screening panel for Qatar. In the evaluated period the applied strategy would have detected all patients with classical homocystinuria identified by the previous strategy and in addition 5 children with maternal nutritional vitamin B12 deficiency and one patient with an isolated remethylation disorder. Additional retrospective evaluation of newborn screening samples of 12 patients from Germany and Qatar with remethlyation disorders or vitamin B12 deficiency showed that all of these patients would have been detected by the cut-offs used in the proposed new strategy. In addition, an adapted strategy for Germany using methionine, methionine-phenylalanine-ratio and propionylcarnitine as first-tier, and homocysteine as a second-tier test was also positively evaluated retrospectively. CONCLUSIONS The proposed strategy for samples from Qatar allows inclusion of remethylation disorders and vitamin B12 deficiency in the screening panel, while lowering the recall rate. An adapted second-tier strategy is presented for screening in Germany and will be prospectively evaluated over the next years in a pilot project named "Newborn Screening 2020".
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Affiliation(s)
- Gwendolyn Gramer
- University of Heidelberg, Center for Pediatric and Adolescent Medicine, Department of General Pediatrics, Division of Neuropediatrics and Metabolic Medicine, Im Neuenheimer Feld 430, 69120, Heidelberg, Germany.
| | - Ghassan Abdoh
- Department of Pediatrics, Hamad Medical Corporation, Doha, Qatar
| | - Tawfeg Ben-Omran
- Department of Pediatrics, Hamad Medical Corporation, Doha, Qatar
| | - Noora Shahbeck
- Department of Pediatrics, Hamad Medical Corporation, Doha, Qatar
| | - Rehab Ali
- Department of Pediatrics, Hamad Medical Corporation, Doha, Qatar
| | - Laila Mahmoud
- Department of Pediatrics, Hamad Medical Corporation, Doha, Qatar
| | - Junmin Fang-Hoffmann
- University of Heidelberg, Center for Pediatric and Adolescent Medicine, Department of General Pediatrics, Division of Neuropediatrics and Metabolic Medicine, Im Neuenheimer Feld 430, 69120, Heidelberg, Germany
| | - Georg F Hoffmann
- University of Heidelberg, Center for Pediatric and Adolescent Medicine, Department of General Pediatrics, Division of Neuropediatrics and Metabolic Medicine, Im Neuenheimer Feld 430, 69120, Heidelberg, Germany
| | - Hilal Al Rifai
- Department of Pediatrics, Hamad Medical Corporation, Doha, Qatar
| | - Jürgen G Okun
- University of Heidelberg, Center for Pediatric and Adolescent Medicine, Department of General Pediatrics, Division of Neuropediatrics and Metabolic Medicine, Im Neuenheimer Feld 430, 69120, Heidelberg, Germany
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15
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Huemer M, Diodato D, Schwahn B, Schiff M, Bandeira A, Benoist JF, Burlina A, Cerone R, Couce ML, Garcia-Cazorla A, la Marca G, Pasquini E, Vilarinho L, Weisfeld-Adams JD, Kožich V, Blom H, Baumgartner MR, Dionisi-Vici C. Guidelines for diagnosis and management of the cobalamin-related remethylation disorders cblC, cblD, cblE, cblF, cblG, cblJ and MTHFR deficiency. J Inherit Metab Dis 2017; 40:21-48. [PMID: 27905001 PMCID: PMC5203859 DOI: 10.1007/s10545-016-9991-4] [Citation(s) in RCA: 180] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 09/28/2016] [Accepted: 10/04/2016] [Indexed: 12/22/2022]
Abstract
BACKGROUND Remethylation defects are rare inherited disorders in which impaired remethylation of homocysteine to methionine leads to accumulation of homocysteine and perturbation of numerous methylation reactions. OBJECTIVE To summarise clinical and biochemical characteristics of these severe disorders and to provide guidelines on diagnosis and management. DATA SOURCES Review, evaluation and discussion of the medical literature (Medline, Cochrane databases) by a panel of experts on these rare diseases following the GRADE approach. KEY RECOMMENDATIONS We strongly recommend measuring plasma total homocysteine in any patient presenting with the combination of neurological and/or visual and/or haematological symptoms, subacute spinal cord degeneration, atypical haemolytic uraemic syndrome or unexplained vascular thrombosis. We strongly recommend to initiate treatment with parenteral hydroxocobalamin without delay in any suspected remethylation disorder; it significantly improves survival and incidence of severe complications. We strongly recommend betaine treatment in individuals with MTHFR deficiency; it improves the outcome and prevents disease when given early.
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Affiliation(s)
- Martina Huemer
- Division of Metabolism and Children's Research Center, University Childrens' Hospital Zürich, Zurich, Switzerland
- radiz - Rare Disease Initiative Zürich, Clinical Research Priority Program, University of Zürich, Zurich, Switzerland
- Department of Paediatrics, Landeskrankenhaus Bregenz, Bregenz, Austria
| | - Daria Diodato
- Division of Metabolism, Bambino Gesù Children's Research Hospital, Rome, Italy
| | - Bernd Schwahn
- Willink Biochemical Genetics Unit, Saint Mary's Hospital, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, M13 9WL, UK
| | - Manuel Schiff
- Reference Center for Inborn Errors of Metabolism, Robert Debré University Hospital, APHP, Paris, France
- Inserm U1141, Robert Debré Hospital, Paris, France
- Université Paris-Diderot, Sorbonne Paris Cité, site Robert Debré, Paris, France
| | | | - Jean-Francois Benoist
- Reference Center for Inborn Errors of Metabolism, Robert Debré University Hospital, APHP, Paris, France
- Inserm U1141, Robert Debré Hospital, Paris, France
- Biochimie, faculté de pharmacie, Université Paris Sud, Paris, France
| | - Alberto Burlina
- Division of Inherited Metabolic Diseases, Department of Pediatrics, University Hospital Padova, Padova, Italy
| | - Roberto Cerone
- University Dept of Pediatrics, Giannina Gaslini Institute, Genoa, Italy
| | - Maria L Couce
- Congenital Metabolic Diseases Unit, Hospital Clínico Universitario de Santiago de Compostela, IDIS, CIBER, Compostela, Spain
| | - Angeles Garcia-Cazorla
- Department of Neurology, Neurometabolism Unit, and CIBERER (ISCIII), Hospital Sant Joan de Deu, Barcelona, Spain
| | - Giancarlo la Marca
- Department of Experimental and Clinical Biomedical Sciences, University of Florence, Firence, Italy
| | - Elisabetta Pasquini
- Metabolic and Newborn Screening Clinical Unit, Department of Neurosciences, A. Meyer Children's University Hospital, Florence, Italy
| | - Laura Vilarinho
- Newborn Screening, Metabolism & Genetics Unit, National Institute of Health, Porto, Portugal
| | - James D Weisfeld-Adams
- Section of Clinical Genetics and Metabolism, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA
- Inherited Metabolic Diseases Clinic, Childrens Hospital Colorado, Aurora, CO, USA
| | - Viktor Kožich
- Institute of Inherited Metabolic Disorders, Charles University-First Faculty of Medicine and General University Hospital, Prague, Czech Republic
| | - Henk Blom
- Laboratory of Clinical Biochemistry and Metabolism, Center for Pediatrics and Adolescent Medicine University Hospital, Freiburg, Freiburg, Germany
| | - Matthias R Baumgartner
- Division of Metabolism and Children's Research Center, University Childrens' Hospital Zürich, Zurich, Switzerland.
- radiz - Rare Disease Initiative Zürich, Clinical Research Priority Program, University of Zürich, Zurich, Switzerland.
| | - Carlo Dionisi-Vici
- Division of Metabolism, Bambino Gesù Children's Research Hospital, Rome, Italy.
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16
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Mutation Update and Review of Severe Methylenetetrahydrofolate Reductase Deficiency. Hum Mutat 2016; 37:427-38. [DOI: 10.1002/humu.22970] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2015] [Accepted: 02/03/2016] [Indexed: 11/07/2022]
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17
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Huemer M, Kožich V, Rinaldo P, Baumgartner MR, Merinero B, Pasquini E, Ribes A, Blom HJ. Newborn screening for homocystinurias and methylation disorders: systematic review and proposed guidelines. J Inherit Metab Dis 2015; 38:1007-19. [PMID: 25762406 PMCID: PMC4626539 DOI: 10.1007/s10545-015-9830-z] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 02/12/2015] [Accepted: 02/23/2015] [Indexed: 01/22/2023]
Abstract
Newborn screening (NBS) is justified if early intervention is effective in a disorder generally not detected early in life on a clinical basis, and if sensitive and specific biochemical markers exist. Experience with NBS for homocystinurias and methylation disorders is limited. However, there is robust evidence for the success of early treatment with diet, betaine and/or pyridoxine for CBS deficiency and good evidence for the success of early betaine treatment in severe MTHFR deficiency. These conditions can be screened in dried blood spots by determining methionine (Met), methionine-to-phenylanine (Met/Phe) ratio, and total homocysteine (tHcy) as a second tier marker. Therefore, we recommend NBS for cystathionine beta-synthase and severe MTHFR deficiency. Weaker evidence is available for the disorders of intracellular cobalamin metabolism. Early treatment is clearly of advantage for patients with the late-onset cblC defect. In the early-onset type, survival and non-neurological symptoms improve but the effect on neurocognitive development is uncertain. The cblC defect can be screened by measuring propionylcarnitine, propionylcarnitine-to-acetylcarnitine ratio combined with the second tier markers methylmalonic acid and tHcy. For the cblE and cblG defects, evidence for the benefit of early treatment is weaker; and data on performance of Met, Met/Phe and tHcy even more limited. Individuals homozygous or compound heterozygous for MAT1A mutations may benefit from detection by NBS using Met, which on the other hand also detects asymptomatic heterozygotes. Clinical and laboratory data is insufficient to develop any recommendation on NBS for the cblD, cblF, cblJ defects, glycineN-methyltransferase-, S-adenosylhomocysteinehydrolase- and adenosine kinase deficiency.
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Affiliation(s)
- Martina Huemer
- Division of Metabolism and Children's Research Center, University Children's Hospital Zürich, Zürich, Switzerland.
- Radiz-Rare Disease Initiative Zürich, University Zürich, Zürich, Switzerland.
- Department of Pediatrics, Landeskrankenhaus Bregenz, Carl-Pedenz-Str. 2, 6900, Bregenz, Austria.
| | - Viktor Kožich
- Institute of Inherited Metabolic Disorders, Charles University in Prague-1st Faculty of Medicine and General University Hospital, Prague, Czech Republic
| | - Piero Rinaldo
- Department Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | - Matthias R Baumgartner
- Division of Metabolism and Children's Research Center, University Children's Hospital Zürich, Zürich, Switzerland
- Radiz-Rare Disease Initiative Zürich, University Zürich, Zürich, Switzerland
| | - Begoña Merinero
- Centro de Diagnóstico de Enfermedades Moleculares, Facultad de Ciencias, Universidad Autónoma de Madrid, IDIPAZ, CIBER de Enfermedades Raras, Madrid, Spain
| | - Elisabetta Pasquini
- Department of Neuroscience, Newborn Screening Unit, A. Meyer University Children's Hospital, Florence, Italy
| | - Antonia Ribes
- Division Inborn Errors of Metabolism, Hospital Clinic, CIBERER, Barcelona, Spain
| | - Henk J Blom
- Laboratory Clinical Biochemistry and Metabolism, Center for Pediatrics and Adolescent Medicine University Hospital, Freiburg, Freiburg, Germany
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Outcomes of four patients with homocysteine remethylation disorders detected by newborn screening. Genet Med 2015; 18:162-7. [PMID: 25856670 DOI: 10.1038/gim.2015.45] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 02/23/2015] [Indexed: 01/21/2023] Open
Abstract
PURPOSE We evaluated the clinical outcome in homocysteine remethylation disorders following newborn screening (NBS) and initiation of early specific treatment. METHODS Five patients with remethylation disorders were included in this study. RESULTS Two asymptomatic patients (one with cblG and one with cblE) were identified by NBS using an approach that combines a postanalytical interpretive tool (available on the Region 4 Stork (R4S) collaborative project website, http://www.clir-r4s.org) and a second-tier test for total homocysteine determination. Both the initial screening and the second-tier test are performed on the same blood spot, with no additional patient contact, resulting in no false-positive outcomes. Two additional patients with methylenetetrahydrofolate reductase deficiency were detected by NBS using low methionine as a marker. Although already symptomatic despite the early diagnosis, the latter two patients greatly improved with treatment and their outcomes are compared with that of another patient with methylenetetrahydrofolate reductase deficiency and significant morbidity who was diagnosed clinically at 3 months of age. CONCLUSION Early detection by NBS and timely and specific treatment considerably improve at least short-term outcomes of homocysteine remethylation disorders. When a remethylation disorder is suspected, group-specific treatment could be started prior to the completion of in vitro confirmatory testing because all disorders from this group require similar intervention.
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Ahrens-Nicklas RC, Serdaroglu E, Muraresku C, Ficicioglu C. Cobalamin C Disease Missed by Newborn Screening in a Patient with Low Carnitine Level. JIMD Rep 2015; 23:71-5. [PMID: 25772322 DOI: 10.1007/8904_2015_429] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 02/12/2015] [Accepted: 02/18/2015] [Indexed: 01/11/2023] Open
Abstract
Cobalamin C (CblC) disease is the most common inherited disorder of intracellular cobalamin metabolism. It is a multisystemic disorder mainly affecting the eye and brain and characterized biochemically by methylmalonic aciduria, low methionine level, and homocystinuria. We report a patient found to have CblC disease who initially presented with low carnitine and normal propionylcarnitine (C3) levels on newborn screen. Newborn screening likely failed to detect CblC in this patient because of both his low carnitine level and the presence of a mild phenotype.
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Newborn Screening for Homocystinuria Revealed a High Frequency of MAT I/III Deficiency in Iberian Peninsula. JIMD Rep 2015; 20:113-20. [PMID: 25638462 DOI: 10.1007/8904_2014_400] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 12/17/2014] [Accepted: 12/18/2014] [Indexed: 01/12/2023] Open
Abstract
Homocystinuria due to cystathionine β-synthase deficiency or "classical homocystinuria" is a rare autosomal recessive condition resulting in altered sulfur metabolism with elevated methionine and homocysteine in plasma and homocystine in urine. This condition is characterized by a high clinical heterogeneity, which contributes to late clinical diagnosis, usually only made after irreversible damage has occurred. Treatment is effective if started before clinical symptoms. The analysis of methionine levels by tandem mass spectrometry (MS/MS) allows the newborn screening for homocystinuria, but false-positive results can be frequently obtained and lead to the unwanted identification of methionine adenosyl transferase (MAT I/III) deficiency. This latter condition is biochemically characterized by isolated persistent hypermethioninemia, accompanied in some individuals with slightly elevated levels of homocysteine in plasma. A dominant form of MAT I/III deficiency, associated with mutation p.R264H, seems to be very frequent in the Iberian Peninsula and usually has a clinically benign course. Both these metabolic disorders are screened in Galicia and Portugal since the introduction of the MS/MS technology, in 2000 and 2004, respectively, resulting in the identification of three patients with classical homocystinuria and 44 patients with MAT I/III deficiency. All but one heterozygous parent of MAT I/III patients, identified with the p.R264H mutation, are healthy adults around the age of 30/40. The implementation of a second-tier test for homocysteine in dried blood spots would considerably reduce the number of MAT I/III-deficient patients identified and improve the specificity and positive predictive value for classical homocystinuria screening.
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Mak CM, Lee HCH, Chan AYW, Lam CW. Inborn errors of metabolism and expanded newborn screening: review and update. Crit Rev Clin Lab Sci 2014; 50:142-62. [PMID: 24295058 DOI: 10.3109/10408363.2013.847896] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Inborn errors of metabolism (IEM) are a phenotypically and genetically heterogeneous group of disorders caused by a defect in a metabolic pathway, leading to malfunctioning metabolism and/or the accumulation of toxic intermediate metabolites. To date, more than 1000 different IEM have been identified. While individually rare, the cumulative incidence has been shown to be upwards of 1 in 800. Clinical presentations are protean, complicating diagnostic pathways. IEM are present in all ethnic groups and across every age. Some IEM are amenable to treatment, with promising outcomes. However, high clinical suspicion alone is not sufficient to reduce morbidities and mortalities. In the last decade, due to the advent of tandem mass spectrometry, expanded newborn screening (NBS) has become a mandatory public health strategy in most developed and developing countries. The technology allows inexpensive simultaneous detection of more than 30 different metabolic disorders in one single blood spot specimen at a cost of about USD 10 per baby, with commendable analytical accuracy and precision. The sensitivity and specificity of this method can be up to 99% and 99.995%, respectively, for most amino acid disorders, organic acidemias, and fatty acid oxidation defects. Cost-effectiveness studies have confirmed that the savings achieved through the use of expanded NBS programs are significantly greater than the costs of implementation. The adverse effects of false positive results are negligible in view of the economic health benefits generated by expanded NBS and these could be minimized through increased education, better communication, and improved technologies. Local screening agencies should be given the autonomy to develop their screening programs in order to keep pace with international advancements. The development of biochemical genetics is closely linked with expanded NBS. With ongoing advancements in nanotechnology and molecular genomics, the field of biochemical genetics is still expanding rapidly. The potential of tandem mass spectrometry is extending to cover more disorders. Indeed, the use of genetic markers in T-cell receptor excision circles for severe combined immunodeficiency is one promising example. NBS represents the highest volume of genetic testing. It is more than a test and it warrants systematic healthcare service delivery across the pre-analytical, analytical, and post-analytical phases. There should be a comprehensive reporting system entailing genetic counselling as well as short-term and long-term follow-up. It is essential to integrate existing clinical IEM services with the expanded NBS program to enable close communication between the laboratory, clinicians, and allied health parties. In this review, we will discuss the history of IEM, its clinical presentations in children and adult patients, and its incidence among different ethnicities; the history and recent expansion of NBS, its cost-effectiveness, associated pros and cons, and the ethical issues that can arise; the analytical aspects of tandem mass spectrometry and post-analytical perspectives regarding result interpretation.
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Affiliation(s)
- Chloe Miu Mak
- Chemical Pathology Laboratory, Department of Pathology, Princess Margaret Hospital , Hong Kong, SAR , China and
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Hall PL, Marquardt G, McHugh DMS, Currier RJ, Tang H, Stoway SD, Rinaldo P. Postanalytical tools improve performance of newborn screening by tandem mass spectrometry. Genet Med 2014; 16:889-95. [PMID: 24875301 PMCID: PMC4262759 DOI: 10.1038/gim.2014.62] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 04/30/2014] [Indexed: 12/02/2022] Open
Abstract
Purpose: The purpose of this study was to compare performance metrics of postanalytical interpretive tools of the Region 4 Stork collaborative project to the actual outcome based on cutoff values for amino acids and acylcarnitines selected by the California newborn screening program. Methods: This study was a retrospective review of the outcome of 176,186 subjects born in California between 1 January and 30 June 2012. Raw data were uploaded to the Region 4 Stork Web portal as .csv files to calculate tool scores for 48 conditions simultaneously using a previously unpublished functionality, the tool runner. Scores for individual target conditions were deemed informative when equal or greater to the value representing the first percentile rank of known true-positive cases (17,099 cases in total). Results: In the study period, the actual false-positive rate and positive predictive value were 0.26 and 10%, respectively. Utilization of the Region 4 Stork tools, simple interpretation rules, and second-tier tests could have achieved a false-positive rate as low as 0.02% and a positive predictive value >50% by replacing the cutoff system with Region 4 Stork tools as the primary method for postanalytical interpretation. Conclusion: Region 4 Stork interpretive tools, second-tier tests, and other evidence-based interpretation rules could have reduced false-positive cases by up to 90% in California.
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Affiliation(s)
- Patricia L Hall
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | - Gregg Marquardt
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | - David M S McHugh
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | - Robert J Currier
- California Department of Public Heath, Richmond, California, USA
| | - Hao Tang
- California Department of Public Heath, Richmond, California, USA
| | - Stephanie D Stoway
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | - Piero Rinaldo
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
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23
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Carrillo-Carrasco N, Chandler RJ, Venditti CP. Combined methylmalonic acidemia and homocystinuria, cblC type. I. Clinical presentations, diagnosis and management. J Inherit Metab Dis 2012; 35:91-102. [PMID: 21748409 PMCID: PMC4219318 DOI: 10.1007/s10545-011-9364-y] [Citation(s) in RCA: 139] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Revised: 05/27/2011] [Accepted: 06/09/2011] [Indexed: 11/25/2022]
Abstract
Combined methylmalonic acidemia and homocystinuria, cblC type, is an inborn error of intracellular cobalamin metabolism with a wide spectrum of clinical manifestations that is stated to be the most common inherited disorder of cobalamin metabolism. This metabolic disease is caused by mutations in the MMACHC gene and results in impaired intracellular synthesis of adenosylcobalamin and methylcobalamin, cofactors for the methylmalonyl-CoA mutase and methionine synthase enzymes. Elevated methylmalonic acid and homocysteine with decreased methionine production are the biochemical hallmarks of this disorder. Awareness of the diverse clinical presentations associated with cblC disease is necessary to provide a timely diagnosis, to guide management of affected individuals and to establish a framework for the future treatment of individuals detected through expanded newborn screening. This article reviews the biochemistry, clinical presentations, genotype-phenotype correlations, diagnosis and management of cblC disease.
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Affiliation(s)
- Nuria Carrillo-Carrasco
- Organic Acid Research Section, Genetics and Molecular Biology Branch, National Human Genome Research Institute, National Institutes of Health, Building 49, Room 4A18, Bethesda, MD 20892, USA
| | - Randy J. Chandler
- Organic Acid Research Section, Genetics and Molecular Biology Branch, National Human Genome Research Institute, National Institutes of Health, Building 49, Room 4A18, Bethesda, MD 20892, USA
- Institute for Biomedical Sciences, The George Washington University, Washington, DC, USA
| | - Charles P. Venditti
- Organic Acid Research Section, Genetics and Molecular Biology Branch, National Human Genome Research Institute, National Institutes of Health, Building 49, Room 4A18, Bethesda, MD 20892, USA
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25
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Alodaib AN, Carpenter K, Wiley V, Wotton T, Christodoulou J, Wilcken B. Homocysteine measurement in dried blood spot for neonatal detection of homocystinurias. JIMD Rep 2011; 5:1-6. [PMID: 23430909 DOI: 10.1007/8904_2011_109] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Revised: 10/03/2011] [Accepted: 10/25/2011] [Indexed: 12/13/2022] Open
Abstract
Expanded newborn screening (NBS) leads to an increased number of false positive results, causing parental anxiety, greater follow-up costs, and the need for further metabolic investigations. We developed and validated a second-tier approach for NBS of homocystinurias by measuring the total homocysteine (tHcy) on the initial dried blood spot (DBS) samples to reduce the need for further investigation, and investigated newborn DBS homocysteine values in patients with homocystinuria. Total DBS homocysteine was measured in normal newborns, and retrospectively in newborns with established disorders, using liquid chromatography tandem mass spectrometry (LC-MS/MS) with stable isotope-labelled internal standards for homocysteine. Analytes were separated using reverse phase chromatography with a total run time of 3 min. The method was linear over the range of 10-100 μmol/L of tHcy and showed excellent precision; intra-batch CV was 4% and inter-batch precision 6.5%. Comparison of 59 plasma values with DBS for tHcy taken at the same time showed excellent correlation, (r (2)>0.97). The reference range for current neonatal samples was 5.4-10.7 μmol/L (n=99), and for the stored neonatal samples (stored dry, sealed in plastic at room temperature for 10 years) was 1.7-5.5 μmol/L, (n=50), both being normally distributed. The clinical utility of this method was checked by retrospective analysis of stored NBS samples from patients with different forms of homocystinuria, including four different remethylating disorders. All had clear elevations of tHcy.
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Affiliation(s)
- Ahmad N Alodaib
- Discipline of Paediatrics and Child Health, University of Sydney, The Children's Hospital at Westmead Clinical School, Locked Bag 4001, Westmead, NSW, 2145, Australia
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Clinical validation of cutoff target ranges in newborn screening of metabolic disorders by tandem mass spectrometry: a worldwide collaborative project. Genet Med 2011; 13:230-54. [PMID: 21325949 DOI: 10.1097/gim.0b013e31820d5e67] [Citation(s) in RCA: 262] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
PURPOSE To achieve clinical validation of cutoff values for newborn screening by tandem mass spectrometry through a worldwide collaborative effort. METHODS Cumulative percentiles of amino acids and acylcarnitines in dried blood spots of approximately 25–30 million normal newborns and 10,742 deidentified true positive cases are compared to assign clinical significance, which is achieved when the median of a disorder range is, and usually markedly outside, either the 99th or the 1st percentile of the normal population. The cutoff target ranges of analytes and ratios are then defined as the interval between selected percentiles of the two populations. When overlaps occur, adjustments are made to maximize sensitivity and specificity taking all available factors into consideration. RESULTS As of December 1, 2010, 130 sites in 45 countries have uploaded a total of 25,114 percentile data points, 565,232 analyte results of true positive cases with 64 conditions, and 5,341 cutoff values. The average rate of submission of true positive cases between December 1, 2008, and December 1, 2010, was 5.1 cases/day. This cumulative evidence generated 91 high and 23 low cutoff target ranges. The overall proportion of cutoff values within the respective target range was 42% (2,269/5,341). CONCLUSION An unprecedented level of cooperation and collaboration has allowed the objective definition of cutoff target ranges for 114 markers to be applied to newborn screening of rare metabolic disorders.
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Pasquali M, Longo N. Newborn screening and inborn errors of metabolism. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2011; 157C:1-2. [PMID: 21337697 DOI: 10.1002/ajmg.c.30290] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Marzia Pasquali
- Biochemical Genetics and Newborn Screening Laboratories, Salt Lake City, UT 84108, USA.
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Mudd SH. Hypermethioninemias of genetic and non-genetic origin: A review. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2011; 157C:3-32. [PMID: 21308989 DOI: 10.1002/ajmg.c.30293] [Citation(s) in RCA: 147] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
This review covers briefly the major conditions, genetic and non-genetic, sometimes leading to abnormally elevated methionine, with emphasis on recent developments. A major aim is to assist in the differential diagnosis of hypermethioninemia. The genetic conditions are: (1) Homocystinuria due to cystathionine β-synthase (CBS) deficiency. At least 150 different mutations in the CBS gene have been identified since this deficiency was established in 1964. Hypermethioninemia is due chiefly to remethylation of the accumulated homocysteine. (2) Deficient activity of methionine adenosyltransferases I and III (MAT I/III), the isoenzymes the catalytic subunit of which are encoded by MAT1A. Methionine accumulates because its conversion to S-adenosylmethionine (AdoMet) is impaired. (3) Glycine N-methyltrasferase (GNMT) deficiency. Disruption of a quantitatively major pathway for AdoMet disposal leads to AdoMet accumulation with secondary down-regulation of methionine flux into AdoMet. (4) S-adenosylhomocysteine (AdoHcy) hydrolase (AHCY) deficiency. Not being catabolized normally, AdoHcy accumulates and inhibits many AdoMet-dependent methyltransferases, producing accumulation of AdoMet and, thereby, hypermethioninemia. (5) Citrin deficiency, found chiefly in Asian countries. Lack of this mitochondrial aspartate-glutamate transporter may produce (usually transient) hypermethioninemia, the immediate cause of which remains uncertain. (6) Fumarylacetoacetate hydrolase (FAH) deficiency (tyrosinemia type I) may lead to hypermethioninemia secondary either to liver damage and/or to accumulation of fumarylacetoacetate, an inhibitor of the high K(m) MAT. Additional possible genetic causes of hypermethioninemia accompanied by elevations of plasma AdoMet include mitochondrial disorders (the specificity and frequency of which remain to be elucidated). Non-genetic conditions include: (a) Liver disease, which may cause hypermethioninemia, mild, or severe. (b) Low-birth-weight and/or prematurity which may cause transient hypermethioninemia. (c) Ingestion of relatively large amounts of methionine which, even in full-term, normal-birth-weight babies may cause hypermethioninemia.
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Affiliation(s)
- S Harvey Mudd
- Laboratory of Molecular Biology, National Institute of Mental Health, Bethesda, MD, USA.
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Turgeon CT, Magera MJ, Cuthbert CD, Loken PR, Gavrilov DK, Tortorelli S, Raymond KM, Oglesbee D, Rinaldo P, Matern D. Determination of total homocysteine, methylmalonic acid, and 2-methylcitric acid in dried blood spots by tandem mass spectrometry. Clin Chem 2010; 56:1686-95. [PMID: 20807894 DOI: 10.1373/clinchem.2010.148957] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Newborn screening (NBS) for inborn errors of propionate, methionine, and cobalamin metabolism relies on finding abnormal concentrations of methionine and propionylcarnitine. These analytes are not specific for these conditions and lead to frequent false-positive results. More specific markers are total homocysteine (tHCY), methylmalonic acid (MMA), and methylcitric acid (MCA), but these markers are not detected by current NBS methods. To improve this situation, we developed a method for the detection of tHCY, MMA, and MCA in dried blood spots (DBSs) by liquid chromatography-tandem mass spectrometry (LC-MS/MS). METHODS The analytes were extracted from a single 4.8-mm DBS punch with acetonitrile:water:formic acid (59:41:0.42) containing dithiothreitol and isotopically labeled standards (d(3)-MMA, d(3)-MCA, d(8)-homocystine). The extract was dried and treated with 3 N HCl in n-butanol to form butylesters. After evaporation of the butanol, the residue was reconstituted and centrifuged and the supernatant was subjected to LC-MS/MS analysis. Algorithms were developed to apply this method as an efficient and effective second-tier assay on samples with abnormal results by primary screening. RESULTS The 99th percentiles determined from the analysis of 200 control DBSs for MMA, MCA, and HCY were 1.5, 0.5, and 9.8 μmol/L, respectively. Since 2005, prospective application of this second-tier analysis to 2.3% of all NBS samples led to the identification of 13 affected infants. CONCLUSIONS Application of this assay reduced the false-positive rate and improved the positive predictive value of NBS for conditions associated with abnormal propionylcarnitine and methionine concentrations.
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Affiliation(s)
- Coleman T Turgeon
- Biochemical Genetics Laboratory, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
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