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Jolfayi AG, Naderi N, Ghasemi S, Salmanipour A, Adimi S, Maleki M, Kalayinia S. A novel pathogenic variant in the carnitine transporter gene, SLC22A5, in association with metabolic carnitine deficiency and cardiomyopathy features. BMC Cardiovasc Disord 2024; 24:1. [PMID: 38166572 PMCID: PMC10763261 DOI: 10.1186/s12872-023-03676-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 12/15/2023] [Indexed: 01/04/2024] Open
Abstract
BACKGROUND Primary carnitine deficiency (PCD) denotes low carnitine levels with an autosomal recessive pattern of inheritance. Cardiomyopathy is the most common cardiac symptom in patients with PCD, and early diagnosis can prevent complications. Next-generation sequencing can identify genetic variants attributable to PCD efficiently. OBJECTIVE We aimed to detect the genetic cause of the early manifestations of hypertrophic cardiomyopathy and metabolic abnormalities in an Iranian family. METHODS We herein describe an 8-year-old boy with symptoms of weakness and lethargy diagnosed with PCD through clinical evaluations, lab tests, echocardiography, and cardiac magnetic resonance imaging. The candidate variant was confirmed through whole-exome sequencing, polymerase chain reaction, and direct Sanger sequencing. The binding efficacy of normal and mutant protein-ligand complexes were evaluated via structural modeling and docking studies. RESULTS Clinical evaluations, echocardiography, and cardiac magnetic resonance imaging findings revealed hypertrophic cardiomyopathy as a clinical presentation of PCD. Whole-exome sequencing identified a new homozygous variant, SLC22A5 (NM_003060.4), c.821G > A: p.Trp274Ter, associated with carnitine transport. Docking analysis highlighted the impact of the variant on carnitine transport, further indicating its potential role in PCD development. CONCLUSIONS The c.821G > A: p.Trp274Ter variant in SLC22A5 potentially acted as a pathogenic factor by reducing the binding affinity of organic carnitine transporter type 2 proteins for carnitine. So, the c.821G > A variant may be associated with carnitine deficiency, metabolic abnormalities, and cardiomyopathic characteristics.
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Affiliation(s)
- Amir Ghaffari Jolfayi
- Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Niloofar Naderi
- Cardiogenetic Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Serwa Ghasemi
- Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Alireza Salmanipour
- Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Sara Adimi
- Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Majid Maleki
- Cardiogenetic Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Samira Kalayinia
- Cardiogenetic Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran.
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2
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García-Vielma C, Lazalde-Córdova LG, Arzola-Hernández JC, González-Aceves EN, López-Zertuche H, Guzmán-Delgado NE, González-Salazar F. Identification of variants in genes associated with hypertrophic cardiomyopathy in Mexican patients. Mol Genet Genomics 2023; 298:1289-1299. [PMID: 37498360 PMCID: PMC10657276 DOI: 10.1007/s00438-023-02048-8] [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: 11/28/2022] [Accepted: 06/22/2023] [Indexed: 07/28/2023]
Abstract
The objective of this work was to identify genetic variants in Mexican patients diagnosed with hypertrophic cardiomyopathy (HCM). According to world literature, the genes mainly involved are MHY7 and MYBPC3, although variants have been found in more than 50 genes related to heart disease and sudden death, and to our knowledge there are no studies in the Mexican population. These variants are reported and classified in the ClinVar (PubMed) database and only some of them are recognized in the Online Mendelian Information in Men (OMIM). The present study included 37 patients, with 14 sporadic cases and 6 familial cases, with a total of 21 index cases. Next-generation sequencing was performed on a predesigned panel of 168 genes associated with heart disease and sudden death. The sequencing analysis revealed twelve (57%) pathogenic or probably pathogenic variants, 9 of them were familial cases, managing to identify pathogenic variants in relatives without symptoms of the disease. At the molecular level, nine of the 12 variants (75%) were single nucleotide changes, 2 (17%) deletions, and 1 (8%) splice site alteration. The genes involved were MYH7 (25%), MYBPC3 (25%) and ACADVL, KCNE1, TNNI3, TPM1, SLC22A5, TNNT2 (8%). In conclusion; we found five variants that were not previously reported in public databases. It is important to follow up on the reclassification of variants, especially those of uncertain significance in patients with symptoms of the condition. All patients included in the study and their relatives received family genetic counseling.
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Affiliation(s)
- Catalina García-Vielma
- Centro de Investigación Biomédica del Noreste, Departamento de Citogenética, Instituto Mexicano del Seguro Social, Monterrey, NL, México.
| | - Luis Gerardo Lazalde-Córdova
- Centro de Investigación Biomédica del Noreste, Departamento de Citogenética, Instituto Mexicano del Seguro Social, Monterrey, NL, México
| | - José Cruz Arzola-Hernández
- Departamento de Electrofisiología, Instituto Mexicano del Seguro Social, Unidad Médica de Alta Especialidad. Hospital de cardiología No. 34 "Dr. Alfonso J. Treviño Treviño" del Centro Médico Nacional del Noreste, Monterrey, NL, México
| | - Erick Noel González-Aceves
- Departamento de Electrofisiología, Instituto Mexicano del Seguro Social, Unidad Médica de Alta Especialidad. Hospital de cardiología No. 34 "Dr. Alfonso J. Treviño Treviño" del Centro Médico Nacional del Noreste, Monterrey, NL, México
| | | | - Nancy Elena Guzmán-Delgado
- Departamento de Electrofisiología, Instituto Mexicano del Seguro Social, Unidad Médica de Alta Especialidad. Hospital de cardiología No. 34 "Dr. Alfonso J. Treviño Treviño" del Centro Médico Nacional del Noreste, Monterrey, NL, México.
| | - Francisco González-Salazar
- Centro de Investigación Biomédica del Noreste, Departamento de Citogenética, Instituto Mexicano del Seguro Social, Monterrey, NL, México
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3
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Hernández Cordero AI, Li X, Milne S, Yang CX, Bossé Y, Joubert P, Timens W, van den Berge M, Nickle D, Hao K, Sin DD. Multi-omics highlights ABO plasma protein as a causal risk factor for COVID-19. Hum Genet 2021; 140:969-979. [PMID: 33604698 PMCID: PMC7892327 DOI: 10.1007/s00439-021-02264-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 02/04/2021] [Indexed: 12/13/2022]
Abstract
SARS-CoV-2 is responsible for the coronavirus disease 2019 (COVID-19) and the current health crisis. Despite intensive research efforts, the genes and pathways that contribute to COVID-19 remain poorly understood. We, therefore, used an integrative genomics (IG) approach to identify candidate genes responsible for COVID-19 and its severity. We used Bayesian colocalization (COLOC) and summary-based Mendelian randomization to combine gene expression quantitative trait loci (eQTLs) from the Lung eQTL (n = 1,038) and eQTLGen (n = 31,784) studies with published COVID-19 genome-wide association study (GWAS) data from the COVID-19 Host Genetics Initiative. Additionally, we used COLOC to integrate plasma protein quantitative trait loci (pQTL) from the INTERVAL study (n = 3,301) with COVID-19 loci. Finally, we determined any causal associations between plasma proteins and COVID-19 using multi-variable two-sample Mendelian randomization (MR). The expression of 18 genes in lung and/or blood co-localized with COVID-19 loci. Of these, 12 genes were in suggestive loci (PGWAS < 5 × 10-05). LZTFL1, SLC6A20, ABO, IL10RB and IFNAR2 and OAS1 had been previously associated with a heightened risk of COVID-19 (PGWAS < 5 × 10-08). We identified a causal association between OAS1 and COVID-19 GWAS. Plasma ABO protein, which is associated with blood type in humans, demonstrated a significant causal relationship with COVID-19 in the MR analysis; increased plasma levels were associated with an increased risk of COVID-19 and, in particular, severe COVID-19. In summary, our study identified genes associated with COVID-19 that may be prioritized for future investigations. Importantly, this is the first study to demonstrate a causal association between plasma ABO protein and COVID-19.
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Affiliation(s)
- Ana I Hernández Cordero
- Centre for Heart Lung Innovation, University of British Columbia, St. Paul's Hospital, Vancouver, BC, Canada.
| | - Xuan Li
- Centre for Heart Lung Innovation, University of British Columbia, St. Paul's Hospital, Vancouver, BC, Canada
| | - Stephen Milne
- Centre for Heart Lung Innovation, University of British Columbia, St. Paul's Hospital, Vancouver, BC, Canada
- Division of Respiratory Medicine, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
- Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
| | - Chen Xi Yang
- Centre for Heart Lung Innovation, University of British Columbia, St. Paul's Hospital, Vancouver, BC, Canada
| | - Yohan Bossé
- Institut Universitaire de Cardiologie Et de Pneumologie de Québec-Université Laval, Québec City, QC, Canada
| | - Philippe Joubert
- Institut Universitaire de Cardiologie Et de Pneumologie de Québec-Université Laval, Québec City, QC, Canada
| | - Wim Timens
- Department of Pathology and Medical Biology, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands
| | - Maarten van den Berge
- Department of Pulmonary Diseases, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - David Nickle
- Global Health, University of Washington, Seattle, WA, USA
- Gossamer Bio, 3013 Science Park Road, San Diego, CA, USA
| | - Ke Hao
- Department of Genetics and Genomic Sciences and Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine At Mount Sinai, New York, NY, USA
| | - Don D Sin
- Centre for Heart Lung Innovation, University of British Columbia, St. Paul's Hospital, Vancouver, BC, Canada
- Division of Respiratory Medicine, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
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Cao J, O'Day DR, Pliner HA, Kingsley PD, Deng M, Daza RM, Zager MA, Aldinger KA, Blecher-Gonen R, Zhang F, Spielmann M, Palis J, Doherty D, Steemers FJ, Glass IA, Trapnell C, Shendure J. A human cell atlas of fetal gene expression. Science 2020; 370:370/6518/eaba7721. [PMID: 33184181 DOI: 10.1126/science.aba7721] [Citation(s) in RCA: 334] [Impact Index Per Article: 83.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 09/10/2020] [Indexed: 12/14/2022]
Abstract
The gene expression program underlying the specification of human cell types is of fundamental interest. We generated human cell atlases of gene expression and chromatin accessibility in fetal tissues. For gene expression, we applied three-level combinatorial indexing to >110 samples representing 15 organs, ultimately profiling ~4 million single cells. We leveraged the literature and other atlases to identify and annotate hundreds of cell types and subtypes, both within and across tissues. Our analyses focused on organ-specific specializations of broadly distributed cell types (such as blood, endothelial, and epithelial), sites of fetal erythropoiesis (which notably included the adrenal gland), and integration with mouse developmental atlases (such as conserved specification of blood cells). These data represent a rich resource for the exploration of in vivo human gene expression in diverse tissues and cell types.
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Affiliation(s)
- Junyue Cao
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA, USA
| | - Diana R O'Day
- Department of Pediatrics, University of Washington School of Medicine, Seattle, WA, USA
| | - Hannah A Pliner
- Brotman Baty Institute for Precision Medicine, Seattle, WA, USA
| | - Paul D Kingsley
- Department of Pediatrics, University of Rochester Medical Center, Rochester, NY, USA
| | - Mei Deng
- Department of Pediatrics, University of Washington School of Medicine, Seattle, WA, USA
| | - Riza M Daza
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA, USA
| | - Michael A Zager
- Brotman Baty Institute for Precision Medicine, Seattle, WA, USA.,Center for Data Visualization, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Kimberly A Aldinger
- Department of Pediatrics, University of Washington School of Medicine, Seattle, WA, USA.,Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, USA
| | - Ronnie Blecher-Gonen
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA, USA
| | | | - Malte Spielmann
- Human Molecular Genomics Group, Max Planck Institute for Molecular Genetics, Berlin, Germany.,Institute of Human Genetics, University of Lübeck, Lübeck, Germany
| | - James Palis
- Department of Pediatrics, University of Rochester Medical Center, Rochester, NY, USA
| | - Dan Doherty
- Department of Pediatrics, University of Washington School of Medicine, Seattle, WA, USA.,Brotman Baty Institute for Precision Medicine, Seattle, WA, USA.,Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, USA
| | | | - Ian A Glass
- Department of Pediatrics, University of Washington School of Medicine, Seattle, WA, USA.,Brotman Baty Institute for Precision Medicine, Seattle, WA, USA.,Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, USA
| | - Cole Trapnell
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA, USA. .,Brotman Baty Institute for Precision Medicine, Seattle, WA, USA.,Allen Discovery Center for Cell Lineage Tracing, Seattle, WA, USA
| | - Jay Shendure
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA, USA. .,Brotman Baty Institute for Precision Medicine, Seattle, WA, USA.,Allen Discovery Center for Cell Lineage Tracing, Seattle, WA, USA.,Howard Hughes Medical Institute, Seattle, WA, USA
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5
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Bene J, Szabo A, Komlósi K, Melegh B. Mass Spectrometric Analysis of L-carnitine and its Esters: Potential Biomarkers of Disturbances in Carnitine Homeostasis. Curr Mol Med 2020; 20:336-354. [PMID: 31729298 PMCID: PMC7231908 DOI: 10.2174/1566524019666191113120828] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 10/31/2019] [Accepted: 11/01/2019] [Indexed: 12/31/2022]
Abstract
PURPOSE After a golden age of classic carnitine research three decades ago, the spread of mass spectrometry opened new perspectives and a much better understanding of the carnitine system is available nowadays. In the classic period, several human and animal studies were focused on various distinct physiological functions of this molecule and these revealed different aspects of carnitine homeostasis in normal and pathological conditions. Initially, the laboratory analyses were based on the classic or radioenzymatic assays, enabling only the determination of free and total carnitine levels and calculation of total carnitine esters' amount without any information on the composition of the acyl groups. The introduction of mass spectrometry allowed the measurement of free carnitine along with the specific and sensitive determination of different carnitine esters. Beyond basic research, mass spectrometry study of carnitine esters was introduced into the newborn screening program because of being capable to detect more than 30 metabolic disorders simultaneously. Furthermore, mass spectrometry measurements were performed to investigate different disease states affecting carnitine homeostasis, such as diabetes, chronic renal failure, celiac disease, cardiovascular diseases, autism spectrum disorder or inflammatory bowel diseases. RESULTS This article will review the recent advances in the field of carnitine research with respect to mass spectrometric analyses of acyl-carnitines in normal and various pathological states. CONCLUSION The growing number of publications using mass spectrometry as a tool to investigate normal physiological conditions or reveal potential biomarkers of primary and secondary carnitine deficiencies shows that this tool brought a new perspective to carnitine research.
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Affiliation(s)
- Judit Bene
- Department of Medical Genetics, Clinical Center, Medical School, University of Pécs, Pécs, Hungary
- Szentágothai Research Centre, University of Pécs, Pécs, Hungary
| | - Andras Szabo
- Department of Medical Genetics, Clinical Center, Medical School, University of Pécs, Pécs, Hungary
- Szentágothai Research Centre, University of Pécs, Pécs, Hungary
| | - Katalin Komlósi
- Department of Medical Genetics, Clinical Center, Medical School, University of Pécs, Pécs, Hungary
| | - Bela Melegh
- Department of Medical Genetics, Clinical Center, Medical School, University of Pécs, Pécs, Hungary
- Szentágothai Research Centre, University of Pécs, Pécs, Hungary
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6
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Zhang Y, Li H, Liu J, Yan H, Liu Q, Wei X, Xi H, Jia Z, Wu L, Wang H. Molecular investigation in Chinese patients with primary carnitine deficiency. Mol Genet Genomic Med 2019; 7:e901. [PMID: 31364285 PMCID: PMC6732302 DOI: 10.1002/mgg3.901] [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: 01/25/2019] [Revised: 07/15/2019] [Accepted: 07/17/2019] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Primary carnitine deficiency (PCD) is an autosomal recessive disorder of carnitine transportation caused by mutations in the SLC22A5 that lead to low serum carnitine levels and decreased intracellular carnitine accumulation. Characteristic clinical findings are hypoketotic hypoglycemia and skeletal and cardiac myopathy. OBJECTIVE To genetically diagnose 24 unrelated Chinese patients with PCD, including 18 infants and six adults. METHODS The entire coding region and the intron-exon boundaries of SLC22A5 were amplified by polymerase chain reaction (PCR). In silico analyses and reverse transcription-polymerase chain reaction (RT-PCR) were used to predict variants' impact on protein structure and function. RESULTS Disease-causing variants in the SLC22A5 were identified in all 24 subjects, and c.288delG, c.495C>A, c.774_775insTCG, c.824+1G>A, and c.1418G>T were novel. The novel variant c.824+1G>A caused a truncated protein p.Phe276Tyrfs*8. CONCLUSIONS We identified 13 variants in the SLC22A5 in 24 PCD patients, and five of these variants are novel mutations. c.824+1G>A was confirmed to alter mRNA splicing by reverse transcription PCR. Furthermore, our findings broaden the mutation spectrum of SLC22A5 and the understanding of the diverse and variable effects of PCD variants.
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Affiliation(s)
- Yanghui Zhang
- Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan, China.,NHC Key Laboratory of Birth Defects Research, Prevention and Treatment (Hunan Provincial Maternal and Child Health Care Hospital), Changsha, Hunan, China
| | - Haoxian Li
- Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan, China.,NHC Key Laboratory of Birth Defects Research, Prevention and Treatment (Hunan Provincial Maternal and Child Health Care Hospital), Changsha, Hunan, China
| | - Jing Liu
- Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan, China.,NHC Key Laboratory of Birth Defects Research, Prevention and Treatment (Hunan Provincial Maternal and Child Health Care Hospital), Changsha, Hunan, China
| | - Huiming Yan
- Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan, China.,NHC Key Laboratory of Birth Defects Research, Prevention and Treatment (Hunan Provincial Maternal and Child Health Care Hospital), Changsha, Hunan, China
| | - Qin Liu
- Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan, China.,NHC Key Laboratory of Birth Defects Research, Prevention and Treatment (Hunan Provincial Maternal and Child Health Care Hospital), Changsha, Hunan, China
| | - Xianda Wei
- National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, Shandong, China
| | - Hui Xi
- Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan, China.,NHC Key Laboratory of Birth Defects Research, Prevention and Treatment (Hunan Provincial Maternal and Child Health Care Hospital), Changsha, Hunan, China
| | - Zhengjun Jia
- Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan, China.,NHC Key Laboratory of Birth Defects Research, Prevention and Treatment (Hunan Provincial Maternal and Child Health Care Hospital), Changsha, Hunan, China
| | - Lingqian Wu
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Hua Wang
- Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan, China.,NHC Key Laboratory of Birth Defects Research, Prevention and Treatment (Hunan Provincial Maternal and Child Health Care Hospital), Changsha, Hunan, China
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Guevara-Campos J, González-Guevara L, Guevara-González J, Cauli O. First Case Report of Primary Carnitine Deficiency Manifested as Intellectual Disability and Autism Spectrum Disorder. Brain Sci 2019; 9:brainsci9060137. [PMID: 31200524 PMCID: PMC6628273 DOI: 10.3390/brainsci9060137] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 06/12/2019] [Accepted: 06/12/2019] [Indexed: 12/26/2022] Open
Abstract
Systemic primary carnitine deficiency (PCD) is a genetic disorder caused by decreased or absent organic cation transporter type 2 (OCTN2) carnitine transporter activity, resulting in low serum carnitine levels and decreased carnitine accumulation inside cells. In early life, PCD is usually diagnosed as a metabolic decompensation, presenting as hypoketotic hypoglycemia, Reye syndrome, or sudden infant death; in childhood, PCD presents with skeletal or cardiac myopathy. However, the clinical presentation of PCD characterized by autism spectrum disorder (ASD) with intellectual disability (ID) has seldom been reported in the literature. In this report, we describe the clinical features of a seven-year-old girl diagnosed with PCD who presented atypical features of the disease, including a developmental delay involving language skills, concentration, and attention span, as well as autistic features and brain alterations apparent in magnetic resonance imaging. We aim to highlight the difficulties related to the diagnostic and therapeutic approaches used to diagnose such patients. The case reported here presented typical signs of PCD, including frequent episodes of hypoglycemia, generalized muscle weakness, decreased muscle mass, and physical growth deficits. A molecular genetic study confirmed the definitive diagnosis of the disease (c.1345T>G (p.Y449D)) in gene SLC22A5, located in exon 8. PCD can be accompanied by less common clinical signs, which may delay its diagnosis because the resulting global clinical picture can closely resemble other metabolic disorders. In this case, the patient was prescribed a carnitine-enriched diet, as well as oral carnitine at a dose of 100 mg/kg/day. PCD has a better prognosis if it is diagnosed and treated early; however, a high level of clinical suspicion is required for its timely and accurate diagnosis.
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Affiliation(s)
- José Guevara-Campos
- "Felipe Guevara Rojas" Hospital, Pediatrics Service, University of Oriente, El Tigre-Anzoátegui 6034, Venezuela.
| | - Lucía González-Guevara
- "Felipe Guevara Rojas" Hospital, Epilepsy and Encephalography Unit, El Tigre-Anzoátegui 6034, Venezuela.
| | | | - Omar Cauli
- Department of Nursing, University of Valencia, 46010 Valencia, Spain.
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Wilson C, Knoll D, de Hora M, Kyle C, Glamuzina E, Webster D. The decision to discontinue screening for carnitine uptake disorder in New Zealand. J Inherit Metab Dis 2019; 42:86-92. [PMID: 30740730 DOI: 10.1002/jimd.12030] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
When screening for carnitine uptake disorder (CUD), the New Zealand (NZ) newborn screening (NBS) service identified infants as screen-positive if they had initial and repeat free carnitine (C0) levels of less than 5.0 μmol/L. Since 2006, the NBS service has identified two infants with biochemical and genetic features consistent with neonatal CUD and nine mothers with features consistent with maternal CUD. A review of the literature suggests that these nine women reflect less than half the true prevalence and that CUD is relatively common. However, the NZ results (two infants) suggest a very low sensitivity and positive predictive value of NBS. While patients presenting with significant disease due to CUD are well described, the majority of adults with CUD are asymptomatic. Nonetheless, treatment with high-dose oral L-carnitine is recommended. Compliance with oral L-carnitine is likely to be poor long term. This may represent a specific risk as treatment could repress the usual compensatory mechanisms seen in CUD, such that a sudden discontinuation of treatment may be dangerous. L-carnitine is metabolized to trimethylamine-N-oxide (TMAO) and treated patients have extremely high plasma TMAO levels. TMAO is an independent risk factor for atherosclerosis and, thus, caution should be exercised regarding long-term treatment with high-dose carnitine of asymptomatic patients who may have a biochemical profile without disease. Due to these concerns, the NZ Newborn Metabolic Screening Programme (NMSP) initiated a review via a series of advisory and governance committees and decided to discontinue screening for CUD.
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Affiliation(s)
- Callum Wilson
- National Metabolic Service, Starship Children's Hospital, P.O. Box 92024, Auckland 1142, New Zealand
| | - Detlef Knoll
- Newborn Metabolic Screening Unit, Auckland City Hospital, Auckland, New Zealand
| | - Mark de Hora
- Newborn Metabolic Screening Programme, LabPlus, Auckland City Hospital, Auckland, New Zealand
| | - Campbell Kyle
- LabPlus, Auckland City Hospital, Auckland, New Zealand
| | - Emma Glamuzina
- National Metabolic Service, Starship Children's Hospital, P.O. Box 92024, Auckland 1142, New Zealand
| | - Dianne Webster
- Newborn Metabolic Screening Programme, LabPlus, Auckland City Hospital, Auckland, New Zealand
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9
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Dehkordi EH, Sobhani P, Asadpour N, Hashemipour M, Mostofizadeh N. Twin Brothers with Carnitine Membrane Transporter Deficiency: A Case Study. Adv Biomed Res 2018; 7:106. [PMID: 30069437 PMCID: PMC6050976 DOI: 10.4103/2277-9175.235779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Carnitine membrane transporter deficiency or primary carnitine deficiency (PCD) is an autosomal recessive disorder of fatty acid oxidation, in which the transport of carnitine into cells is impaired. Carnitine plays an important role in transporting fatty acids into the mitochondria and carnitine deficiency block oxidation of long-chain fatty acids in the mitochondria that leads to heart and hepatic disease, myopathy, nonketotic hypoglycemia, and neurological complications. PCD has a wide range of symptoms and can reveal itself as symptomatic cardiomyopathy or even asymptomatic. In this study, we reported twin brothers with PCD. One of them had symptoms of disease and cardiomyopathy and was under treatment with carnitine. Another twin was asymptomatic and was diagnosed during follow-up period of his brother.
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Affiliation(s)
- Elham Hashemi Dehkordi
- Department of Pediatric Endocrinology, Isfahan University of Medical Sciences, Isfahan, Iran.,Child Growth and Development Research Center, Research Institute for Primordial Prevention of Noncommunicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Payam Sobhani
- Department of Pediatric Endocrinology, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Nabiolah Asadpour
- Department of Pediatric Cardiology, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Mahin Hashemipour
- Department of Pediatric Endocrinology, Isfahan University of Medical Sciences, Isfahan, Iran.,Child Growth and Development Research Center, Research Institute for Primordial Prevention of Noncommunicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran.,Endocrine and Metabolism Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Neda Mostofizadeh
- Department of Pediatric Endocrinology, Isfahan University of Medical Sciences, Isfahan, Iran.,Child Growth and Development Research Center, Research Institute for Primordial Prevention of Noncommunicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran
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Guo K, Zhou X, Chen X, Wu Y, Liu C, Kong Q. Expanded Newborn Screening for Inborn Errors of Metabolism and Genetic Characteristics in a Chinese Population. Front Genet 2018; 9:122. [PMID: 29731766 PMCID: PMC5920142 DOI: 10.3389/fgene.2018.00122] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 03/26/2018] [Indexed: 12/24/2022] Open
Abstract
The incidence of inborn errors of metabolisms (IEMs) varies dramatically in different countries and regions. Expanded newborn screening for IEMs by tandem mass spectrometry (MS/MS) is an efficient approach for early diagnosis and presymptomatic treatment to prevent severe permanent sequelae and death. To determine the characteristics of IEMs and IEMs-associated mutations in newborns in Jining area, China, 48,297 healthy neonates were recruited for expanded newborn screening by MS/MS. The incidence of IEMs was 1/1178 in Jining, while methylmalonic acidemia, phenylketonuria, and primary carnitine deficiency ranked the top 3 of all detected IEMs. Thirty mutations in nine IEMs-associated genes were identified in 28 confirmed cases. As 19 cases with the mutations in phenylalanine hydroxylase (PAH), solute carrier family 22 member 5 (SLC22A5), and methylmalonic aciduria (cobalamin deficiency) cblC type with homocystinuria (MMACHC) genes, respectively, it suggested that mutations in the PAH, SLC22A5, and MMACHC genes are the predominant causes of IEMs, leading to the high incidence of phenylketonuria, primary carnitine deficiency, and methylmalonic acidemia, respectively. Our work indicated that the overall incidence of IEMs is high and the mutations in PAH, SLC22A5, and MMACHC genes are the leading causes of IEMs in Jining area. Therefore, it is critical to increase the coverage of expanded newborn screening by MS/MS and prenatal genetic consulting in Jining area.
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Affiliation(s)
- Kejian Guo
- Jining Maternal and Child Health Care Hospital, Jining, China
| | - Xuan Zhou
- Department of Psychiatry, Jining Medical University, Jining, China.,Shandong Key Laboratory of Behavioral Medicine, Jining Medical University, Jining, China
| | - Xigui Chen
- Jining Maternal and Child Health Care Hospital, Jining, China
| | - Yili Wu
- Department of Psychiatry, Jining Medical University, Jining, China.,Shandong Key Laboratory of Behavioral Medicine, Jining Medical University, Jining, China.,Collaborative Innovation Center for Birth Defect Research and Transformation of Shandong Province, Jining Medical University, Jining, China
| | - Chuanxin Liu
- Department of Psychiatry, Jining Medical University, Jining, China.,Collaborative Innovation Center for Birth Defect Research and Transformation of Shandong Province, Jining Medical University, Jining, China
| | - Qingsheng Kong
- Collaborative Innovation Center for Birth Defect Research and Transformation of Shandong Province, Jining Medical University, Jining, China.,Department of Biochemistry, Jining Medical University, Jining, China
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Frigeni M, Balakrishnan B, Yin X, Calderon FRO, Mao R, Pasquali M, Longo N. Functional and molecular studies in primary carnitine deficiency. Hum Mutat 2017; 38:1684-1699. [PMID: 28841266 DOI: 10.1002/humu.23315] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 08/13/2017] [Accepted: 08/17/2017] [Indexed: 12/30/2022]
Abstract
Primary carnitine deficiency is caused by a defect in the OCTN2 carnitine transporter encoded by the SLC22A5 gene. It can cause hypoketotic hypoglycemia or cardiomyopathy in children, and sudden death in children and adults. Fibroblasts from affected patients have reduced carnitine transport. We evaluated carnitine transport in fibroblasts from 358 subjects referred for possible carnitine deficiency. Carnitine transport was reduced to 20% or less of normal in fibroblasts of 140 out of 358 subjects. Sequencing of the 10 exons and flanking regions of the SLC22A5 gene in 95 out of 140 subjects identified causative variants in 84% of the alleles. The missense variants identified in our patients and others previously reported (n = 92) were expressed in CHO cells. Carnitine transport was impaired by 73 out of 92 variants expressed. Prediction algorithms (Polyphen-2, SIFT) correctly predicted the functional effects of expressed variants in about 80% of cases. These results indicate that mutations in the coding region of the SLC22A5 gene cannot be identified in about 16% of the alleles causing primary carnitine deficiency. Prediction algorithms failed to determine the functional effects of amino acid substitutions in this transmembrane protein in about 20% of cases. Therefore, functional studies in fibroblasts remain the best strategy to confirm or exclude a diagnosis of primary carnitine deficiency.
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Affiliation(s)
- Marta Frigeni
- Division of Medical Genetics/Pediatrics, University of Utah, Salt Lake City, Utah
| | - Bijina Balakrishnan
- Division of Medical Genetics/Pediatrics, University of Utah, Salt Lake City, Utah
| | - Xue Yin
- Division of Medical Genetics/Pediatrics, University of Utah, Salt Lake City, Utah
| | - Fernanda R O Calderon
- ARUP Institute for Clinical and Experimental Pathology®, ARUP Laboratories, Salt Lake City, Utah.,Department of Pathology, University of Utah, Salt Lake City, Utah
| | - Rong Mao
- ARUP Institute for Clinical and Experimental Pathology®, ARUP Laboratories, Salt Lake City, Utah.,Department of Pathology, University of Utah, Salt Lake City, Utah
| | - Marzia Pasquali
- Division of Medical Genetics/Pediatrics, University of Utah, Salt Lake City, Utah.,ARUP Institute for Clinical and Experimental Pathology®, ARUP Laboratories, Salt Lake City, Utah.,Department of Pathology, University of Utah, Salt Lake City, Utah
| | - Nicola Longo
- Division of Medical Genetics/Pediatrics, University of Utah, Salt Lake City, Utah.,ARUP Institute for Clinical and Experimental Pathology®, ARUP Laboratories, Salt Lake City, Utah.,Department of Pathology, University of Utah, Salt Lake City, Utah
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Longo N, Frigeni M, Pasquali M. Carnitine transport and fatty acid oxidation. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:2422-35. [PMID: 26828774 DOI: 10.1016/j.bbamcr.2016.01.023] [Citation(s) in RCA: 470] [Impact Index Per Article: 58.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 01/27/2016] [Accepted: 01/28/2016] [Indexed: 12/14/2022]
Abstract
Carnitine is essential for the transfer of long-chain fatty acids across the inner mitochondrial membrane for subsequent β-oxidation. It can be synthesized by the body or assumed with the diet from meat and dairy products. Defects in carnitine biosynthesis do not routinely result in low plasma carnitine levels. Carnitine is accumulated by the cells and retained by kidneys using OCTN2, a high affinity organic cation transporter specific for carnitine. Defects in the OCTN2 carnitine transporter results in autosomal recessive primary carnitine deficiency characterized by decreased intracellular carnitine accumulation, increased losses of carnitine in the urine, and low serum carnitine levels. Patients can present early in life with hypoketotic hypoglycemia and hepatic encephalopathy, or later in life with skeletal and cardiac myopathy or sudden death from cardiac arrhythmia, usually triggered by fasting or catabolic state. This disease responds to oral carnitine that, in pharmacological doses, enters cells using the amino acid transporter B(0,+). Primary carnitine deficiency can be suspected from the clinical presentation or identified by low levels of free carnitine (C0) in the newborn screening. Some adult patients have been diagnosed following the birth of an unaffected child with very low carnitine levels in the newborn screening. The diagnosis is confirmed by measuring low carnitine uptake in the patients' fibroblasts or by DNA sequencing of the SLC22A5 gene encoding the OCTN2 carnitine transporter. Some mutations are specific for certain ethnic backgrounds, but the majority are private and identified only in individual families. Although the genotype usually does not correlate with metabolic or cardiac involvement in primary carnitine deficiency, patients presenting as adults tend to have at least one missense mutation retaining residual activity. This article is part of a Special Issue entitled: Mitochondrial Channels edited by Pierre Sonveaux, Pierre Maechler and Jean-Claude Martinou.
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Affiliation(s)
- Nicola Longo
- Division of Medical Genetics, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA; Department of Pathology, University of Utah, and ARUP Laboratories, 500 Chipeta Way, Salt Lake City, UT, USA.
| | - Marta Frigeni
- Division of Medical Genetics, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Marzia Pasquali
- Department of Pathology, University of Utah, and ARUP Laboratories, 500 Chipeta Way, Salt Lake City, UT, USA
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