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Pode-Shakked B, Landau YE, Shaul Lotan N, Manor J, Haham N, Kristal E, Hershkovitz E, Hazan G, Haham Y, Almashanu S, Anikster Y, Staretz-Chacham O. The natural history of dihydrolipoamide dehydrogenase deficiency in Israel. J Inherit Metab Dis 2024. [PMID: 39040027 DOI: 10.1002/jimd.12778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Revised: 06/13/2024] [Accepted: 06/20/2024] [Indexed: 07/24/2024]
Abstract
Dihydrolipoamide dehydrogenase (DLD) deficiency is an ultra-rare autosomal-recessive inborn error of metabolism, affecting no less than five mitochondrial multienzyme complexes. With approximately 30 patients reported to date, DLD deficiency was associated with three major clinical presentations: an early-onset encephalopathic phenotype with metabolic acidosis, a predominantly hepatic presentation with liver failure, and a rare myopathic phenotype. To elucidate the demographic, phenotypic, and molecular characteristics of patients with DLD deficiency within the Israeli population, data were collected from metabolic disease specialists in four large tertiary medical centers in the center and south of Israel. Pediatric and adult patients with biallelic variants in DLD were included in the study. A total of 53 patients of 35 families were included in the cohort. Age at presentation ranged between birth and 10 years. Wide phenotypic variability was observed, from asymptomatic individuals in their sixth decade of life, to severe, neonatal-onset disease with devastating neurological sequelae. Six DLD variants were noted, the most common of which was the c.685G>T (p.G229C) variant in homozygous form (24/53 patients, 45.3%; 13/35 families), observed mostly among patients of Ashkenazi-Jewish descent, followed by the homozygous c.1436A>T (p.D479V) variant, found in 20 patients of Bedouin descent (37.7%; 16/35 families). Overall, patients did not necessarily present as one of the previously described distinct clinical phenotypes. DLD deficiency is a panethnic disorder, with significant phenotypic variability, and comprises a continuum, rather than three distinct clinical presentations.
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Affiliation(s)
- Ben Pode-Shakked
- Metabolic Disease Unit, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel
- School of Medicine, Faculty of Medical and Health Sciences, Tel-Aviv University, Tel-Aviv, Israel
| | - Yuval E Landau
- School of Medicine, Faculty of Medical and Health Sciences, Tel-Aviv University, Tel-Aviv, Israel
- Metabolic Disease Unit, Schneider Children's Medical Center of Israel, Petah-Tikva, Israel
| | - Nava Shaul Lotan
- Department of Genetics, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - Joshua Manor
- Metabolic Disease Unit, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel
- School of Medicine, Faculty of Medical and Health Sciences, Tel-Aviv University, Tel-Aviv, Israel
| | - Nitsan Haham
- Pediatrics Department, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel
| | - Eyal Kristal
- Pediatric Ambulatory Day Unit, Soroka Medical Center, Beer Sheva, Israel
- Faculty of Health Sciences, Ben-Gurion University, Beer Sheva, Israel
| | - Eli Hershkovitz
- Faculty of Health Sciences, Ben-Gurion University, Beer Sheva, Israel
- Metabolic Clinic, Pediatric Division, Soroka University Medical Center, Beer Sheva, Israel
- Pediatric Department D, Soroka University Medical Center, Beer Sheva, Israel
| | - Guy Hazan
- Faculty of Health Sciences, Ben-Gurion University, Beer Sheva, Israel
- Pediatric Department D, Soroka University Medical Center, Beer Sheva, Israel
| | - Yarden Haham
- School of Medicine, Faculty of Medical and Health Sciences, Tel-Aviv University, Tel-Aviv, Israel
| | - Shlomo Almashanu
- National Newborn Screening Program, Public Health Services, Ministry of Health, Ramat-Gan, Israel
| | - Yair Anikster
- Metabolic Disease Unit, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel
- School of Medicine, Faculty of Medical and Health Sciences, Tel-Aviv University, Tel-Aviv, Israel
| | - Orna Staretz-Chacham
- Faculty of Health Sciences, Ben-Gurion University, Beer Sheva, Israel
- Metabolic Clinic, Pediatric Division, Soroka University Medical Center, Beer Sheva, Israel
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2
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Verma A, Lehman AN, Gokcan H, Cropcho L, Black D, Dobrowolski SF, Vockley J, Bedoyan JK. Amino acid ratio combinations as biomarkers for discriminating patients with pyruvate dehydrogenase complex deficiency from other inborn errors of metabolism. Mol Genet Genomic Med 2024; 12:e2283. [PMID: 37688338 PMCID: PMC10767461 DOI: 10.1002/mgg3.2283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 08/17/2023] [Accepted: 08/29/2023] [Indexed: 09/10/2023] Open
Abstract
BACKGROUND Pyruvate dehydrogenase complex deficiency (PDCD) is a mitochondrial neurometabolic disorder of energy deficit, with incidence of about 1 in 42,000 live births annually in the USA. The median and mean ages of diagnosis of PDCD are about 12 and 31 months, respectively. PDCD is a major cause of primary lactic acidosis with concomitant elevation in blood alanine (Ala) and proline (Pro) concentrations depending on phenotypic severity. Alanine/Leucine (Ala/Leu) ≥4.0 and Proline/Leucine (Pro/Leu) ≥3.0 combination cutoff from dried blood spot specimens was used as a biomarker for early identification of neonates/infants with PDCD. Further investigations were needed to evaluate the sensitivity (SN), specificity (SP), and clinical utility of such amino acid (AA) ratio combination cutoffs in discriminating PDCD from other inborn errors of metabolism (IEM) for early identification of such patients. METHODS We reviewed medical records of patients seen at UPMC in the past 11 years with molecularly or enzymatically confirmed diagnosis. We collected plasma AA analysis data from samples prior to initiation of therapeutic interventions such as total parenteral nutrition and/or ketogenic diet. Conditions evaluated included organic acidemias, primary mitochondrial disorders (MtDs), fatty acid oxidation disorders (FAOD), other IEMs on current newborn screening panels, congenital cardiac great vessel anomalies, renal tubular acidosis, and non-IEMs. The utility of specific AA ratio combinations as biomarkers were evaluated using receiver operating characteristic curves, correlation analysis, principal component analysis, and cutoff SN, SP, and positive predictive value determined from 201 subjects with broad age range. RESULTS Alanine/Lysine (Ala/Lys) and Ala/Leu as well as (Ala + Pro)/(Leu + Lys) and Ala/Leu ratio combinations effectively discriminated subjects with PDCD from those with other MtDs and IEMs on current newborn screening panels. Specific AA ratio combinations were significantly more sensitive in identifying PDCD than Ala alone or combinations of Ala and/or Pro in the evaluated cohort of subjects. Ala/Lys ≥3.0 and Ala/Leu ≥5.0 as well as (Ala + Pro)/(Leu + Lys) ≥2.5 and Ala/Leu ≥5.0 combination cutoffs identified patients with PDCD with 100% SN and ~85% SP. CONCLUSIONS With the best predictor of survival and positive cognitive outcome in PDCD being age of diagnosis, PDCD patients would benefit from use of such highly SN and SP AA ratio combination cutoffs as biomarkers for early identification of at-risk newborns, infants, and children, for early intervention(s) with known and/or novel therapeutics for this disorder.
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Affiliation(s)
- Anisha Verma
- West Virginia School of Osteopathic MedicineLewisburgWest VirginiaUSA
| | - April N. Lehman
- UPMC Children's Hospital of PittsburghPittsburghPennsylvaniaUSA
| | - Hatice Gokcan
- Department of ChemistryCarnegie Mellon UniversityPittsburghPennsylvaniaUSA
| | - Lorna Cropcho
- UPMC Children's Hospital of PittsburghPittsburghPennsylvaniaUSA
| | - Danielle Black
- UPMC Children's Hospital of PittsburghPittsburghPennsylvaniaUSA
| | - Steven F. Dobrowolski
- UPMC Children's Hospital of PittsburghPittsburghPennsylvaniaUSA
- Department of PathologyUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Jerry Vockley
- UPMC Children's Hospital of PittsburghPittsburghPennsylvaniaUSA
- Division of Genetic and Genomic Medicine, Department of PediatricsUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Jirair K. Bedoyan
- UPMC Children's Hospital of PittsburghPittsburghPennsylvaniaUSA
- Division of Genetic and Genomic Medicine, Department of PediatricsUniversity of PittsburghPittsburghPennsylvaniaUSA
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Kouřil Š, de Sousa J, Fačevicová K, Gardlo A, Muehlmann C, Nordhausen K, Friedecký D, Adam T. Multivariate Independent Component Analysis Identifies Patients in Newborn Screening Equally to Adjusted Reference Ranges. Int J Neonatal Screen 2023; 9:60. [PMID: 37873851 PMCID: PMC10594528 DOI: 10.3390/ijns9040060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 09/22/2023] [Accepted: 10/17/2023] [Indexed: 10/25/2023] Open
Abstract
Newborn screening (NBS) of inborn errors of metabolism (IEMs) is based on the reference ranges established on a healthy newborn population using quantile statistics of molar concentrations of biomarkers and their ratios. The aim of this paper is to investigate whether multivariate independent component analysis (ICA) is a useful tool for the analysis of NBS data, and also to address the structure of the calculated ICA scores. NBS data were obtained from a routine NBS program performed between 2013 and 2022. ICA was tested on 10,213/150 free-diseased controls and 77/20 patients (9/3 different IEMs) in the discovery/validation phases, respectively. The same model computed during the discovery phase was used in the validation phase to confirm its validity. The plots of ICA scores were constructed, and the results were evaluated based on 5sd levels. Patient samples from 7/3 different diseases were clearly identified as 5sd-outlying from control groups in both phases of the study. Two IEMs containing only one patient each were separated at the 3sd level in the discovery phase. Moreover, in one latent variable, the effect of neonatal birth weight was evident. The results strongly suggest that ICA, together with an interpretation derived from values of the "average member of the score structure", is generally applicable and has the potential to be included in the decision process in the NBS program.
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Affiliation(s)
- Štěpán Kouřil
- Department of Clinical Biochemistry, University Hospital Olomouc, 779 00 Olomouc, Czech Republic (D.F.)
| | - Julie de Sousa
- Laboratory of Metabolomics, Institute of Molecular and Translational Medicine, Palacký University Olomouc, 779 00 Olomouc, Czech Republic
- Department of Mathematical Analysis and Applications of Mathematics, Faculty of Science, Palacký University Olomouc, 779 00 Olomouc, Czech Republic;
| | - Kamila Fačevicová
- Department of Mathematical Analysis and Applications of Mathematics, Faculty of Science, Palacký University Olomouc, 779 00 Olomouc, Czech Republic;
| | - Alžběta Gardlo
- Department of Clinical Biochemistry, University Hospital Olomouc, 779 00 Olomouc, Czech Republic (D.F.)
- Laboratory of Metabolomics, Institute of Molecular and Translational Medicine, Palacký University Olomouc, 779 00 Olomouc, Czech Republic
| | - Christoph Muehlmann
- Institute of Statistics & Mathematical Methods in Economics, Vienna University of Technology, 1040 Vienna, Austria
| | - Klaus Nordhausen
- Department of Mathematics and Statistics, University of Jyväskylä, 40014 Jyväskylä, Finland
| | - David Friedecký
- Department of Clinical Biochemistry, University Hospital Olomouc, 779 00 Olomouc, Czech Republic (D.F.)
| | - Tomáš Adam
- Department of Clinical Biochemistry, University Hospital Olomouc, 779 00 Olomouc, Czech Republic (D.F.)
- Laboratory of Metabolomics, Institute of Molecular and Translational Medicine, Palacký University Olomouc, 779 00 Olomouc, Czech Republic
- Faculty of Health Care, The Slovak Medical University in Bratislava, 974 05 Banská Bystrica, Slovakia
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Baker PR. Recognizing and Managing a Metabolic Crisis. Pediatr Clin North Am 2023; 70:979-993. [PMID: 37704355 DOI: 10.1016/j.pcl.2023.05.009] [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] [Indexed: 09/15/2023]
Abstract
In some relatively common inborn errors of metabolism there can be the accumulation of toxic compounds including ammonia and organic acids such as lactate and ketoacids, as well as energy deficits at the cellular level. The clinical presentation is often referred to as a metabolic emergency or crisis. Fasting and illness can result in encephalopathy within hours, and without appropriate recognition and intervention, the outcome may be permanent disability or death. This review outlines easy and readily available means of recognizing and diagnosing a metabolic emergency as well as general guidelines for management. Disease-specific interventions focus on parenteral nutrition to reverse catabolism, toxin removal strategies, and vitamin/nutrition supplementation.
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Affiliation(s)
- Peter R Baker
- University of Colorado, Children's Hospital Colorado, 13123 East 16th Avenue, Box 300, Aurora, CO 80045, USA.
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5
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Lasio MLD, Leshinski AC, Ducich NH, Flore LA, Lehman A, Shur N, Jayakar PB, Hainline BE, Basinger AA, Wilson WG, Diaz GA, Erbe RW, Koeberl DD, Vockley J, Bedoyan JK. Clinical, biochemical and molecular characterization of 12 patients with pyruvate carboxylase deficiency treated with triheptanoin. Mol Genet Metab 2023; 139:107605. [PMID: 37207470 PMCID: PMC10330474 DOI: 10.1016/j.ymgme.2023.107605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 05/05/2023] [Accepted: 05/06/2023] [Indexed: 05/21/2023]
Abstract
Pyruvate carboxylase (PC) deficiency is a rare autosomal recessive mitochondrial neurometabolic disorder of energy deficit resulting in high morbidity and mortality, with limited therapeutic options. The PC homotetramer has a critical role in gluconeogenesis, anaplerosis, neurotransmitter synthesis, and lipogenesis. The main biochemical and clinical findings in PC deficiency (PCD) include lactic acidosis, ketonuria, failure to thrive, and neurological dysfunction. Use of the anaplerotic agent triheptanoin on a limited number of individuals with PCD has had mixed results. We expand on the potential utility of triheptanoin in PCD by examining the clinical, biochemical, molecular, and health-related quality-of-life (HRQoL) findings in a cohort of 12 individuals with PCD (eight with Type A and two each with Types B and C) treated with triheptanoin ranging for 6 days to about 7 years. The main endpoints were changes in blood lactate and HRQoL scores, but collection of useful data was limited to about half of subjects. An overall trend of lactate reduction with time on triheptanoin was noted, but with significant variability among subjects and only one subject reaching close to statistical significance for this endpoint. Parent reported HRQoL assessments with treatment showed mixed results, with some subjects showing no change, some improvement, and some worsening of overall scores. Subjects with buried amino acids in the pyruvate carboxyltransferase domain of PC that undergo destabilizing replacements may be more likely to respond (with lactate reduction or HRQoL improvement) to triheptanoin compared to those with replacements that disrupt tetramerization or subunit-subunit interface contacts. The reason for this difference is unclear and requires further validation. We observed significant variability but an overall trend of lactate reduction with time on triheptanoin and mixed parent reported outcome changes by HRQoL assessments for subjects with PCD on long-term triheptanoin. The mixed results noted with triheptanoin therapy in this study could be due to endpoint data limitation, variability of disease severity between subjects, limitation of the parent reported HRQoL tool, or subject genotype variability. Alternative designed trials and more study subjects with PCD will be needed to validate important observations from this work.
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Affiliation(s)
- M Laura Duque Lasio
- Department of Pathology, University of Utah, Salt Lake City, UT, USA; Division of Genetic and Genomic Medicine, UPMC Children's Hospital of Pittsburgh and Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Angela C Leshinski
- Division of Genetic and Genomic Medicine, UPMC Children's Hospital of Pittsburgh and Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Nicole H Ducich
- Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Leigh Anne Flore
- Division of Genetic, Genomic and Metabolic Disorders, Children's Hospital of Michigan, Detroit, MI and Central Michigan University College of Medicine, Mount Pleasant, MI, USA
| | - April Lehman
- Division of Genetic and Genomic Medicine, UPMC Children's Hospital of Pittsburgh and Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; Division of Genetic, Genomic and Metabolic Disorders, Children's Hospital of Michigan, Detroit, MI and Central Michigan University College of Medicine, Mount Pleasant, MI, USA
| | - Natasha Shur
- Genetics and Metabolism, Rare Disease Institute, Children's National Hospital, Washington, DC, USA
| | - Parul B Jayakar
- Division of Genetics and Metabolism, Nicklaus Children's Hospital, Miami, FL, USA
| | - Bryan E Hainline
- Department of Medical and Molecular Genetics, Riley Hospital at Indiana University Health, Indianapolis, IN, USA
| | | | - William G Wilson
- Department of Pediatrics, University of Virginia Health, Charlottesville, VA, USA
| | - George A Diaz
- Division of Genetics and Genomics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Richard W Erbe
- Departments of Pediatrics and Medicine, University at Buffalo, Buffalo, NY, USA
| | - Dwight D Koeberl
- Department of Pediatrics, Duke University Medical Center, Durham, NC, USA
| | - Jerry Vockley
- Division of Genetic and Genomic Medicine, UPMC Children's Hospital of Pittsburgh and Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; Department of Human Genetics, University of Pittsburgh School of Public Health, Pittsburgh, PA, USA
| | - Jirair K Bedoyan
- Division of Genetic and Genomic Medicine, UPMC Children's Hospital of Pittsburgh and Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
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6
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He XY, Dobkin C, Brown WT, Yang SY. Infantile Neurodegeneration Results from Mutants of 17β-Hydroxysteroid Dehydrogenase Type 10 Rather Than Aβ-Binding Alcohol Dehydrogenase. Int J Mol Sci 2023; 24:ijms24108487. [PMID: 37239833 DOI: 10.3390/ijms24108487] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 04/27/2023] [Accepted: 05/02/2023] [Indexed: 05/28/2023] Open
Abstract
Type 10 17β-hydroxysteroid dehydrogenase (17β-HSD10), a homo-tetrameric multifunctional protein with 1044 residues encoded by the HSD17B10 gene, is necessary for brain cognitive function. Missense mutations result in infantile neurodegeneration, an inborn error in isoleucine metabolism. A 5-methylcytosine hotspot underlying a 388-T transition leads to the HSD10 (p.R130C) mutant to be responsible for approximately half of all cases suffering with this mitochondrial disease. Fewer females suffer with this disease due to X-inactivation. The binding capability of this dehydrogenase to Aβ-peptide may play a role in Alzheimer's disease, but it appears unrelated to infantile neurodegeneration. Research on this enzyme was complicated by reports of a purported Aβ-peptide-binding alcohol dehydrogenase (ABAD), formerly referred to as endoplasmic-reticulum-associated Aβ-binding protein (ERAB). Reports concerning both ABAD and ERAB in the literature reflect features inconsistent with the known functions of 17β-HSD10. It is clarified here that ERAB is reportedly a longer subunit of 17β-HSD10 (262 residues). 17β-HSD10 exhibits L-3-hydroxyacyl-CoA dehydrogenase activity and is thus also referred to in the literature as short-chain 3-hydorxyacyl-CoA dehydrogenase or type II 3-hydorxyacyl-CoA dehydrogenase. However, 17β-HSD10 is not involved in ketone body metabolism, as reported in the literature for ABAD. Reports in the literature referring to ABAD (i.e., 17β-HSD10) as a generalized alcohol dehydrogenase, relying on data underlying ABAD's activities, were found to be unreproducible. Furthermore, the rediscovery of ABAD/ERAB's mitochondrial localization did not cite any published research on 17β-HSD10. Clarification of the purported ABAD/ERAB function derived from these reports on ABAD/ERAB may invigorate this research field and encourage new approaches to the understanding and treatment of HSD17B10-gene-related disorders. We establish here that infantile neurodegeneration is caused by mutants of 17β-HSD10 but not ABAD, and so we conclude that ABAD represents a misnomer employed in high-impact journals.
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Affiliation(s)
- Xue-Ying He
- Department of Molecular Biology, NYS Institute for Basic Research in Developmental Disabilities, Staten Island, NY 10314, USA
| | - Carl Dobkin
- Department of Human Genetics, NYS Institute for Basic Research in Developmental Disabilities, Staten Island, NY 10314, USA
| | - William Ted Brown
- Central Clinical School, University of Sydney, Sydney 2006, Australia
| | - Song-Yu Yang
- Department of Molecular Biology, NYS Institute for Basic Research in Developmental Disabilities, Staten Island, NY 10314, USA
- Ph.D. Program in Biology-Neuroscience, Graduate Center, City University of New York, New York, NY 10016, USA
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7
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Gill EL, Wang J, Viaene AN, Master SR, Ganetzky RD. Methodologies in Mitochondrial Testing: Diagnosing a Primary Mitochondrial Respiratory Chain Disorder. Clin Chem 2023:7143230. [PMID: 37099687 DOI: 10.1093/clinchem/hvad037] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 03/03/2023] [Indexed: 04/28/2023]
Abstract
BACKGROUND Mitochondria are cytosolic organelles within most eukaryotic cells. Mitochondria generate the majority of cellular energy in the form of adenosine triphosphate (ATP) through oxidative phosphorylation (OxPhos). Pathogenic variants in mitochondrial DNA (mtDNA) and nuclear DNA (nDNA) lead to defects in OxPhos and physiological malfunctions (Nat Rev Dis Primer 2016;2:16080.). Patients with primary mitochondrial disorders (PMD) experience heterogeneous symptoms, typically in multiple organ systems, depending on the tissues affected by mitochondrial dysfunction. Because of this heterogeneity, clinical diagnosis is challenging (Annu Rev Genomics Hum Genet 2017;18:257-75.). Laboratory diagnosis of mitochondrial disease depends on a multipronged analysis that can include biochemical, histopathologic, and genetic testing. Each of these modalities has complementary strengths and limitations in diagnostic utility. CONTENT The primary focus of this review is on diagnosis and testing strategies for primary mitochondrial diseases. We review tissue samples utilized for testing, metabolic signatures, histologic findings, and molecular testing approaches. We conclude with future perspectives on mitochondrial testing. SUMMARY This review offers an overview of the current biochemical, histologic, and genetic approaches available for mitochondrial testing. For each we review their diagnostic utility including complementary strengths and weaknesses. We identify gaps in current testing and possible future avenues for test development.
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Affiliation(s)
- Emily L Gill
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, United States
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Jing Wang
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, United States
| | - Angela N Viaene
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, United States
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Stephen R Master
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, United States
| | - Rebecca D Ganetzky
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, United States
- Division of Human Genetics, Children's Hospital of Philadelphia, Mitochondrial Medicine Frontier Program, Philadelphia, PA, United States
- Department of Pediatrics, University of Pennsylvania, Philadelphia, PA, United States
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8
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Karissa P, Simpson T, Dawson SP, Low TY, Tay SH, Nordin FDA, Zain SM, Lee PY, Pung YF. Comparison Between Dichloroacetate and Phenylbutyrate Treatment for Pyruvate Dehydrogenase Deficiency. Br J Biomed Sci 2022; 79:10382. [PMID: 35996497 PMCID: PMC9302545 DOI: 10.3389/bjbs.2022.10382] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 04/27/2022] [Indexed: 11/13/2022]
Abstract
Pyruvate dehydrogenase (PDH) deficiency is caused by a number of pathogenic variants and the most common are found in the PDHA1 gene. The PDHA1 gene encodes one of the subunits of the PDH enzyme found in a carbohydrate metabolism pathway involved in energy production. Pathogenic variants of PDHA1 gene usually impact the α-subunit of PDH causing energy reduction. It potentially leads to increased mortality in sufferers. Potential treatments for this disease include dichloroacetate and phenylbutyrate, previously used for other diseases such as cancer and maple syrup urine disease. However, not much is known about their efficacy in treating PDH deficiency. Effective treatment for PDH deficiency is crucial as carbohydrate is needed in a healthy diet and rice is the staple food for a large portion of the Asian population. This review analysed the efficacy of dichloroacetate and phenylbutyrate as potential treatments for PDH deficiency caused by PDHA1 pathogenic variants. Based on the findings of this review, dichloroacetate will have an effect on most PDHA1 pathogenic variant and can act as a temporary treatment to reduce the lactic acidosis, a common symptom of PDH deficiency. Phenylbutyrate can only be used on patients with certain pathogenic variants (p.P221L, p.R234G, p.G249R, p.R349C, p.R349H) on the PDH protein. It is hoped that the review would provide an insight into these treatments and improve the quality of lives for patients with PDH deficiency.
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Affiliation(s)
- Patricia Karissa
- Division of Biomedical Science, Faculty of Science and Engineering, University of Nottingham Malaysia, Semenyih, Malaysia
| | - Timothy Simpson
- Faculty of Medicine and Health Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Simon P Dawson
- Faculty of Medicine and Health Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Teck Yew Low
- UKM Medical Molecular Biology Institute (UMBI), Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Sook Hui Tay
- Division of Biomedical Science, Faculty of Science and Engineering, University of Nottingham Malaysia, Semenyih, Malaysia
| | | | - Shamsul Mohd Zain
- Department of Pharmacology, Faculty of Medicine, University Malaya, Kuala Lumpur, Malaysia
| | - Pey Yee Lee
- UKM Medical Molecular Biology Institute (UMBI), Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Yuh-Fen Pung
- Division of Biomedical Science, Faculty of Science and Engineering, University of Nottingham Malaysia, Semenyih, Malaysia
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9
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Ducich NH, Mears JA, Bedoyan JK. Solvent accessibility of E1α and E1β residues with known missense mutations causing pyruvate dehydrogenase complex (PDC) deficiency: Impact on PDC-E1 structure and function. J Inherit Metab Dis 2022; 45:557-570. [PMID: 35038180 PMCID: PMC9297371 DOI: 10.1002/jimd.12477] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2021] [Revised: 01/11/2022] [Accepted: 01/12/2022] [Indexed: 11/08/2022]
Abstract
Pyruvate dehydrogenase complex deficiency is a major cause of primary lactic acidemia resulting in high morbidity and mortality, with limited therapeutic options. PDHA1 mutations are responsible for >82% of cases. The E1 component of PDC is a symmetric dimer of heterodimers (αβ/α'β') encoded by PDHA1 and PDHB. We measured solvent accessibility surface area (SASA), utilized nearest-neighbor analysis, incorporated sequence changes using mutagenesis tool in PyMOL, and performed molecular modeling with SWISS-MODEL, to investigate the impact of residues with disease-causing missense variants (DMVs) on E1 structure and function. We reviewed 166 and 13 genetically resolved cases due to PDHA1 and PDHB, respectively, from variant databases. We expanded on 102 E1α and 13 E1β nonduplicate DMVs. DMVs of E1α Arg112-Arg224 stretch (exons 5-7) and of E1α Arg residues constituted 40% and 39% of cases, respectively, with invariant Arg349 accounting for 22% of arginine replacements. SASA analysis showed that 86% and 84% of residues with nonduplicate DMVs of E1α and E1β, respectively, are solvent inaccessible ("buried"). Furthermore, 30% of E1α buried residues with DMVs are deleterious through perturbation of subunit-subunit interface contact (SSIC), with 73% located in the Arg112-Arg224 stretch. E1α Arg349 represented 74% of buried E1α Arg residues involved in SSIC. Structural perturbations resulting from residue replacements in some matched neighboring pairs of amino acids on different subunits involved in SSIC at 2.9-4.0 Å interatomic distance apart, exhibit similar clinical phenotype. Collectively, this work provides insight for future target-based advanced molecular modeling studies, with implications for development of novel therapeutics for specific recurrent DMVs of E1α.
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Affiliation(s)
- Nicole H. Ducich
- Case Western Reserve University (CWRU) School of Medicine, Cleveland, Ohio, USA
| | - Jason A. Mears
- Department of Pharmacology, CWRU, Cleveland, Ohio, USA
- Center for Mitochondrial Diseases, CWRU, Cleveland, Ohio, USA
| | - Jirair K. Bedoyan
- Division of Genetic and Genomic Medicine, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Pediatrics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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