1
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Lin Y, Yang Z, Yang C, Hu H, He H, Niu T, Liu M, Wang D, Sun Y, Shen Y, Li X, Yan H, Kong Y, Huang X. C4OH is a potential newborn screening marker-a multicenter retrospective study of patients with beta-ketothiolase deficiency in China. Orphanet J Rare Dis 2021; 16:224. [PMID: 34001203 PMCID: PMC8130433 DOI: 10.1186/s13023-021-01859-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 05/06/2021] [Indexed: 12/27/2022] Open
Abstract
Background Beta-ketothiolase deficiency (BKTD) is an autosomal recessive disorder caused by biallelic mutation of ACAT1 that affects both isoleucine catabolism and ketolysis. There is little information available regarding the incidence, newborn screening (NBS), and mutational spectrum of BKTD in China. Results We collected NBS, biochemical, clinical, and ACAT1 mutation data from 18 provinces or municipalities in China between January 2009 and May 2020, and systematically assessed all available published data from Chinese BKTD patients. A total of 16,088,190 newborns were screened and 14 patients were identified through NBS, with an estimated incidence of 1 per 1 million newborns in China. In total, twenty-nine patients were genetically diagnosed with BKTD, 12 of which were newly identified. Most patients exhibited typical blood acylcarnitine and urinary organic acid profiles. Interestingly, almost all patients (15/16, 94%) showed elevated 3-hydroxybutyrylcarnitine (C4OH) levels. Eighteen patients presented with acute metabolic decompensations and displayed variable clinical symptoms. The acute episodes of nine patients were triggered by infections, diarrhea, or an inflammatory response to vaccination. Approximately two-thirds of patients had favorable outcomes, one showed a developmental delay and three died. Twenty-seven distinct variants were identified in ACAT1, among which five were found to be novel. Conclusion This study presented the largest series of BKTD cohorts in China. Our results indicated that C4OH is a useful marker for the detection of BKTD. The performance of BKTD NBS could be improved by the addition of C4OH to the current panel of 3-hydroxyisovalerylcarnitine and tiglylcarnitine markers in NBS. The mutational spectrum and molecular profiles of ACAT1 in the Chinese population were expanded with five newly identified variants. Supplementary Information The online version contains supplementary material available at 10.1186/s13023-021-01859-5.
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Affiliation(s)
- Yiming Lin
- Department of Genetics and Metabolism, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, 3333 Binsheng Road, Hangzhou, 310052, China.,Neonatal Disease Screening Center, Quanzhou Maternity and Children's Hospital, Quanzhou, China
| | - Zhantao Yang
- Continuing Medical Education and Research Center, Dian Diagnostics Group Co., Ltd, 329 Jinpeng Street, Xihu District, Hangzhou, 310030, China
| | - Chiju Yang
- Jining Maternal and Child Health Family Service Center, Jining, China
| | - Haili Hu
- Neonatal Disease Screening Center, Hefei Maternal and Child Health, Family Planning Service Center, Anhui, China
| | - Haiyan He
- Wuhu Maternal and Child Health Family Planning Service Center, Anhui, China
| | - Tingting Niu
- Shandong Provincial Maternal and Child Health Care Hospital, Shandong, China
| | - Mingfang Liu
- Liaocheng Maternal and Child Health Hospital, Shandong, China
| | - Dongjuan Wang
- Center for Clinical Molecular Medicine/Newborn Screening Center, Children's Hospital, Chongqing Medical University, Chongqing, China
| | - Yun Sun
- Nanjing Maternity and Child Health Care Hospital, Women's Hospital of Nanjing Medical University, Jiangsu, China
| | - Yuyan Shen
- Neonatal Disease Screening Center, Huaihua Maternal and Child Health Hospital, Huaihua, China
| | - Xiaole Li
- Third Affiliated Hospital of Zhengzhou University, Henan, China
| | - Huiming Yan
- Department of Genetic Medicine, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan, China
| | - Yuanyuan Kong
- Department of Newborn Screening, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, 251 Yaojiayuan Road, Chaoyang District, Beijing, 100026, China
| | - Xinwen Huang
- Department of Genetics and Metabolism, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, 3333 Binsheng Road, Hangzhou, 310052, China.
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2
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Abdelkreem E, Harijan RK, Yamaguchi S, Wierenga RK, Fukao T. Mutation update on ACAT1 variants associated with mitochondrial acetoacetyl-CoA thiolase (T2) deficiency. Hum Mutat 2019; 40:1641-1663. [PMID: 31268215 PMCID: PMC6790690 DOI: 10.1002/humu.23831] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2019] [Revised: 05/27/2019] [Accepted: 05/31/2019] [Indexed: 02/05/2023]
Abstract
Mitochondrial acetoacetyl‐CoA thiolase (T2, encoded by the ACAT1 gene) deficiency is an inherited disorder of ketone body and isoleucine metabolism. It typically manifests with episodic ketoacidosis. The presence of isoleucine‐derived metabolites is the key marker for biochemical diagnosis. To date, 105 ACAT1 variants have been reported in 149 T2‐deficient patients. The 56 disease‐associated missense ACAT1 variants have been mapped onto the crystal structure of T2. Almost all these missense variants concern residues that are completely or partially buried in the T2 structure. Such variants are expected to cause T2 deficiency by having lower in vivo T2 activity because of lower folding efficiency and/or stability. Expression and activity data of 30 disease‐associated missense ACAT1 variants have been measured by expressing them in human SV40‐transformed fibroblasts. Only two variants (p.Cys126Ser and p.Tyr219His) appear to have equal stability as wild‐type. For these variants, which are inactive, the side chains point into the active site. In patients with T2 deficiency, the genotype does not correlate with the clinical phenotype but exerts a considerable effect on the biochemical phenotype. This could be related to variable remaining residual T2 activity in vivo and has important clinical implications concerning disease management and newborn screening.
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Affiliation(s)
- Elsayed Abdelkreem
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu, Japan.,Department of Pediatrics, Faculty of Medicine, Sohag University, Sohag, Egypt
| | - Rajesh K Harijan
- Department of Biochemistry, Albert Einstein College of Medicine, New York, New York
| | - Seiji Yamaguchi
- Department of Pediatrics, Shimane University School of Medicine, Izumo, Japan
| | | | - Toshiyuki Fukao
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu, Japan
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3
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Yang Y, Jiang SH, Liu S, Han XY, Wang Y, Wang LL, Yu B. Two Infants With Beta-Ketothiolase Deficiency Identified by Newborn Screening in China. Front Genet 2019; 10:451. [PMID: 31156707 PMCID: PMC6530354 DOI: 10.3389/fgene.2019.00451] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 04/30/2019] [Indexed: 11/13/2022] Open
Abstract
Beta-ketothiolase deficiency (BKTD) is an autosomal recessive disease caused by a defect of mitochondrial acetoacetyl-CoA thiolase. Beginning in 2014, we carried out newborn screening by tandem mass spectrometry (MS/MS) followed by next-generation sequencing (NGS) and identified two infants with BKTD among 203,750 newborns born in Jiangsu Province, China. Both infants showed the characteristic chemical abnormalities of BKTD. We used NGS to confirm variants in the ACAT1. Patient 1 had the compound heterozygous variants c.721dupA and c.928G > C. Patient 2 had compound heterozygosity for the c.238+1G > A and c.1163G > T variants. c.721dupA, c.928G > C and c.1163G > T were suspected to be likely pathogenic, whereas c.238+1G > A was determined to be pathogenic. None of the four variants have been reported in the literature. Patient 1 presented with onset of metabolic acidosis and neonatal hypoglycemia 8 days after birth, whereas patient 2 was detected through neonatal disease screening but had no clinical manifestations. These findings contribute to our understanding of the clinical characteristics and genetic basis of BKTD.
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Affiliation(s)
- Yuqi Yang
- Changzhou Maternity and Child Health Care Hospital, Nanjing Medical University, Changzhou, China
| | - Shu hong Jiang
- Changzhou Maternity and Child Health Care Hospital, Nanjing Medical University, Changzhou, China
| | - Shuang Liu
- Lianyungang Maternal and Child Health Hospital, Yangzhou University, Lianyungang, China
| | - Xiao ya Han
- Changzhou Maternity and Child Health Care Hospital, Nanjing Medical University, Changzhou, China
| | - Ying Wang
- Changzhou Maternity and Child Health Care Hospital, Nanjing Medical University, Changzhou, China
| | - Lei lei Wang
- Lianyungang Maternal and Child Health Hospital, Yangzhou University, Lianyungang, China
| | - Bin Yu
- Changzhou Maternity and Child Health Care Hospital, Nanjing Medical University, Changzhou, China
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4
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Fukao T, Sasai H, Aoyama Y, Otsuka H, Ago Y, Matsumoto H, Abdelkreem E. Recent advances in understanding beta-ketothiolase (mitochondrial acetoacetyl-CoA thiolase, T2) deficiency. J Hum Genet 2018; 64:99-111. [PMID: 30393371 DOI: 10.1038/s10038-018-0524-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 09/18/2018] [Accepted: 10/03/2018] [Indexed: 02/08/2023]
Abstract
Beta-ketothiolase (mitochondrial acetoacetyl-CoA thiolase, T2) deficiency (OMIM #203750, *607809) is an inborn error of metabolism that affects isoleucine catabolism and ketone body metabolism. This disorder is clinically characterized by intermittent ketoacidotic crises under ketogenic stresses. In addition to a previous 26-case series, four series of T2-deficient patients were recently reported from different regions. In these series, most T2-deficient patients developed their first ketoacidotic crises between the ages of 6 months and 3 years. Most patients experienced less than three metabolic crises. Newborn screening (NBS) for T2 deficiency is performed in some countries but some T2-deficient patients have been missed by NBS. Therefore, T2 deficiency should be considered in patients with severe metabolic acidosis, even in regions where NBS for T2 deficiency is performed. Neurological manifestations, especially extrapyramidal manifestations, can occur as sequelae to severe metabolic acidosis; however, this can also occur in patients without any apparent metabolic crisis or before the onset of metabolic crisis.
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Affiliation(s)
- Toshiyuki Fukao
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu, 500-1194, Japan. .,Division of Clinical Genetics, Gifu University Hospital, Gifu, Japan.
| | - Hideo Sasai
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu, 500-1194, Japan
| | - Yuka Aoyama
- Department of Biomedical Sciences, College of Life and Health Sciences, Education and Training Center of Medical Technology, Chubu University, Kasugai, Japan
| | - Hiroki Otsuka
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu, 500-1194, Japan
| | - Yasuhiko Ago
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu, 500-1194, Japan
| | - Hideki Matsumoto
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu, 500-1194, Japan
| | - Elsayed Abdelkreem
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu, 500-1194, Japan.,Department of Pediatrics, Faculty of Medicine, Sohag University, Sohag, Egypt
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5
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Marshall AC, Bond CS, Bruning JB. Structure of Aspergillus fumigatus Cytosolic Thiolase: Trapped Tetrahedral Reaction Intermediates and Activation by Monovalent Cations. ACS Catal 2018. [DOI: 10.1021/acscatal.7b02873] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Andrew C. Marshall
- Institute
for Photonics and Advanced Sensing (IPAS), School of Biological Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Charles S. Bond
- School
of Molecular Sciences, The University of Western Australia, Crawley, Western Australia 6009, Australia
| | - John B. Bruning
- Institute
for Photonics and Advanced Sensing (IPAS), School of Biological Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia
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6
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Su L, Li X, Lin R, Sheng H, Feng Z, Liu L. Clinical and molecular analysis of 6 Chinese patients with isoleucine metabolism defects: identification of 3 novel mutations in the HSD17B10 and ACAT1 gene. Metab Brain Dis 2017; 32:2063-2071. [PMID: 28875337 DOI: 10.1007/s11011-017-0097-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2017] [Accepted: 08/16/2017] [Indexed: 01/16/2023]
Abstract
Hydroxysteroid (17β) dehydrogenase 10 (HSD10) and mitochondrial acetoacetyl-CoA thiolase (β-KT) are two adjacent enzymes for the degradation of isoleucine, thus HSD10 and β-KT deficiencies are confusing at an early stage because of nearly the same elevation of typical metabolites in urine, such as 2-methyl-3-hydroxybutyric acid (2M3HBA) and tiglylglycine (TG). In order to better understand the differences between these two disorders, we described the clinical and molecular characteristics of two HSD10 deficiency patients and four β-KT deficiency patients. β-KT deficiency patients had a much more favorable outcome than that of HSD10 deficiency patients, indicating that the multifunction of HSD10, especially neurosteroid metabolic activity, other than only enzymatic degradation of isoleucine, is involved in the pathogenesis of HSD10 deficiency. Two different mutations, a novel mutation p.Ile175Met and a reported mutation p.Arg226Gln, were detected in the HSD17B10 gene of HSD10 deficiency patients. Six different mutations, including four known mutations: p.Ala333Pro, p.Thr297Lys, c.83_84delAT, c.1006-1G > C, and two novel mutations: p.Thr277Pro and c.121-3C > G were identified in the ACAT1 gene of β-KT deficiency patients. In general, DNA diagnosis played an important role in distinguishing between these two disorders.
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MESH Headings
- 3-Hydroxyacyl CoA Dehydrogenases/genetics
- Acetyl-CoA C-Acetyltransferase/genetics
- Acetyl-CoA C-Acyltransferase/deficiency
- Acetyl-CoA C-Acyltransferase/genetics
- Acetyl-CoA C-Acyltransferase/metabolism
- Amino Acid Metabolism, Inborn Errors/diagnosis
- Amino Acid Metabolism, Inborn Errors/diagnostic imaging
- Amino Acid Metabolism, Inborn Errors/genetics
- Amino Acid Metabolism, Inborn Errors/metabolism
- Brain/diagnostic imaging
- Child, Preschool
- China
- Diagnosis, Differential
- Dyskinesias/diagnosis
- Dyskinesias/diagnostic imaging
- Dyskinesias/genetics
- Dyskinesias/metabolism
- Epilepsy/genetics
- Epilepsy/metabolism
- Female
- Humans
- Infant
- Isoleucine/metabolism
- Male
- Mental Retardation, X-Linked/diagnosis
- Mental Retardation, X-Linked/diagnostic imaging
- Mental Retardation, X-Linked/genetics
- Mental Retardation, X-Linked/metabolism
- Models, Molecular
- Mutation
- Retrospective Studies
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Affiliation(s)
- Ling Su
- Southern Medical University, Guangzhou, 510515, China
| | - Xiuzhen Li
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Road, Guangzhou, 510623, China
| | - Ruizhu Lin
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Road, Guangzhou, 510623, China
| | - Huiying Sheng
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Road, Guangzhou, 510623, China
| | - Zhichun Feng
- Southern Medical University, Guangzhou, 510515, China.
- Department of Neonatology, Affiliated Bayi Children's Hospital, Clinical Medical College in PLA Army General Hospital, Southern Medical University, Beijing, 100007, China.
| | - Li Liu
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Road, Guangzhou, 510623, China.
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7
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Grünert SC, Schmitt RN, Schlatter SM, Gemperle-Britschgi C, Balcı MC, Berg V, Çoker M, Das AM, Demirkol M, Derks TGJ, Gökçay G, Uçar SK, Konstantopoulou V, Christoph Korenke G, Lotz-Havla AS, Schlune A, Staufner C, Tran C, Visser G, Schwab KO, Fukao T, Sass JO. Clinical presentation and outcome in a series of 32 patients with 2-methylacetoacetyl-coenzyme A thiolase (MAT) deficiency. Mol Genet Metab 2017; 122:67-75. [PMID: 28689740 DOI: 10.1016/j.ymgme.2017.06.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2017] [Revised: 06/25/2017] [Accepted: 06/25/2017] [Indexed: 12/21/2022]
Abstract
2-methylacetoacetyl-coenzyme A thiolase (MAT) deficiency, also known as beta-ketothiolase deficiency, is an inborn error of ketone body utilization and isoleucine catabolism. It is caused by mutations in the ACAT1 gene and may present with metabolic ketoacidosis. In order to obtain a more comprehensive view on this disease, we have collected clinical and biochemical data as well as information on ACAT1 mutations of 32 patients from 12 metabolic centers in five countries. Patients were between 23months and 27years old, more than half of them were offspring of a consanguineous union. 63% of the study participants presented with a metabolic decompensation while most others were identified via newborn screening or family studies. In symptomatic patients, age at manifestation ranged between 5months and 6.8years. Only 7% developed a major mental disability while the vast majority was cognitively normal. More than one third of the identified mutations in ACAT1 are intronic mutations which are expected to disturb splicing. We identified several novel mutations but, in agreement with previous reports, no clear genotype-phenotype correlation could be found. Our study underlines that the prognosis in MAT deficiency is good and MAT deficient individuals may remain asymptomatic, if diagnosed early and preventive measures are applied.
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Affiliation(s)
- Sarah Catharina Grünert
- Department of General Pediatrics, Adolescent Medicine and Neonatology, Medical Center - University of Freiburg, Faculty of Medicine, Freiburg, Germany
| | - Robert Niklas Schmitt
- Department of General Pediatrics, Adolescent Medicine and Neonatology, Medical Center - University of Freiburg, Faculty of Medicine, Freiburg, Germany
| | - Sonja Marina Schlatter
- Department of General Pediatrics, Adolescent Medicine and Neonatology, Medical Center - University of Freiburg, Faculty of Medicine, Freiburg, Germany
| | - Corinne Gemperle-Britschgi
- Clinical Chemistry & Biochemistry and Children's Research Center, University Children's Hospital, Zürich, Switzerland
| | - Mehmet Cihan Balcı
- Division of Pediatric Nutrition and Metabolism, Department of Pediatrics, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey
| | | | - Mahmut Çoker
- Metabolism Unit, Department of Pediatrics, Ege University Medical Faculty, Izmir, Turkey
| | - Anibh M Das
- University Children's Hospital, Hannover Medical School, Hannover, Germany
| | - Mübeccel Demirkol
- Division of Pediatric Nutrition and Metabolism, Department of Pediatrics, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey
| | - Terry G J Derks
- Section of Metabolic Diseases, Beatrix Children's Hospital, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Gülden Gökçay
- Division of Pediatric Nutrition and Metabolism, Department of Pediatrics, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey
| | - Sema Kalkan Uçar
- Metabolism Unit, Department of Pediatrics, Ege University Medical Faculty, Izmir, Turkey
| | | | | | | | - Andrea Schlune
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, University Children's Hospital, Heinrich Heine University, Düsseldorf, Germany
| | - Christian Staufner
- Department of General Pediatrics, Division of Neuropediatrics and Pediatric Metabolic Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Christel Tran
- Center for Molecular Diseases, Divison of Genetic Medicine, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - Gepke Visser
- Wilhelmina Children's Hospital, University Medical Centre Utrecht, Utrecht, The Netherlands
| | - Karl Otfried Schwab
- Department of General Pediatrics, Adolescent Medicine and Neonatology, Medical Center - University of Freiburg, Faculty of Medicine, Freiburg, Germany
| | - Toshiyuki Fukao
- Department of Pediatrics, Graduate School of Medicine, Gifu University, and Division of Clinical Genetics, Gifu University Hospital, Gifu, Japan
| | - Jörn Oliver Sass
- Department of General Pediatrics, Adolescent Medicine and Neonatology, Medical Center - University of Freiburg, Faculty of Medicine, Freiburg, Germany; Clinical Chemistry & Biochemistry and Children's Research Center, University Children's Hospital, Zürich, Switzerland; Bioanalytics & Biochemistry, Department of Natural Sciences, University of Applied Sciences, Rheinbach, Germany.
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8
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Abdelkreem E, Alobaidy H, Aoyama Y, Mahmoud S, Abd El Aal M, Fukao T. Two Libyan siblings with beta-ketothiolase deficiency: A case report and review of literature. EGYPTIAN JOURNAL OF MEDICAL HUMAN GENETICS 2017. [DOI: 10.1016/j.ejmhg.2016.11.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
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9
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Clinical and Mutational Characterizations of Ten Indian Patients with Beta-Ketothiolase Deficiency. JIMD Rep 2016; 35:59-65. [PMID: 27928777 DOI: 10.1007/8904_2016_26] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 11/13/2016] [Accepted: 11/16/2016] [Indexed: 02/05/2023] Open
Abstract
Beta-ketothiolase deficiency (mitochondrial acetoacetyl-CoA thiolase (T2) deficiency) is an inherited disease of isoleucine catabolism and ketone body utilization caused by ACAT1 mutations. We identified ten Indian patients who manifested with ketoacidotic episodes of variable severity. The patients showed increased urinary excretion of isoleucine-catabolic intermediates: 2-methyl-3-hydroxybutyrate, 2-methylacetoacetate, and tiglylglycine. Six patients had a favorable outcome, one died, and three developed neurodevelopmental sequela. Mutational analysis revealed a common (p.Met193Arg) and four novel (p.Ile323Thr, p.Ala215Asn, c.1012_1015dup, and c.730+1G>A) ACAT1 mutations. Transient expression analyses of wild-type and mutant cDNA were performed at 30, 37, and 40°C. A p.Ile323Thr mutant T2 was detected with relative enzyme activity and protein amount of 20% and 25%, respectively, compared with wild type at 37°C; it was more prevalent at 30°C but ablated at 40°C. These findings showed that p.Ile323Thr had a significant residual T2 activity with temperature-sensitive instability. Neither residual enzymatic activity nor mutant T2 protein was identified in p.Met193Arg, p.Ala215Asn, and c.1012_1015dup mutations using supernatants; however, these mutant T2 proteins were detected in insoluble pellets by immunoblot analysis. Expression analyses confirmed pathogenicity of these mutations. T2 deficiency has a likely high incidence in India and p.Met193Arg may be a common mutation in the Indian population.
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10
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Otsuka H, Sasai H, Nakama M, Aoyama Y, Abdelkreem E, Ohnishi H, Konstantopoulou V, Sass JO, Fukao T. Exon 10 skipping in ACAT1 caused by a novel c.949G>A mutation located at an exonic splice enhancer site. Mol Med Rep 2016; 14:4906-4910. [PMID: 27748876 DOI: 10.3892/mmr.2016.5819] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Accepted: 08/25/2016] [Indexed: 02/05/2023] Open
Abstract
Beta-ketothiolase deficiency, also known as mitochondrial acetoacetyl-CoA thiolase (T2) deficiency, is an autosomal recessive disease caused by mutations in the acetyl‑CoA acetyltransferase 1 (ACAT1) gene. A German T2‑deficient patient that developed a severe ketoacidotic episode at the age of 11 months, was revealed to be a compound heterozygote of a previously reported null mutation, c.472A>G (p.N158D) and a novel mutation, c.949G>A (p.D317N), in ACAT1. The c.949G>A mutation was suspected to cause aberrant splicing as it is located within an exonic splicing enhancer sequence (c. 947CTGACGC) that is a potential binding site for serine/arginine‑rich splicing factor 1. A mutation in this sequence, c.951C>T, results in exon 10 skipping. A minigene construct was synthesized that included exon 9‑truncated intron 9‑exon 10‑truncated intron 10‑exon 11, and the splicing of this minigene revealed that the c.949G>A mutant construct caused exon 10 skipping in a proportion of the transcripts. Furthermore, additional substitution of G for C at the first nucleotide of exon 10 (c.941G>C) abolished the effect of the c.949G>A mutation. Transient expression analysis of the c.949G>A mutant cDNA revealed no residual T2 activity in the mutated D317N enzyme. Therefore, c.949G>A (D317N) is a pathogenic missense mutation, and diminishes the effect of an exonic splicing enhancer and causes exon 10 skipping. The present study demonstrates that a missense mutation, or even a synonymous substitution, may disrupt enzyme function by interference with splicing.
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Affiliation(s)
- Hiroki Otsuka
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu 501‑1194, Japan
| | - Hideo Sasai
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu 501‑1194, Japan
| | - Mina Nakama
- Division of Clinical Genetics, Gifu University Hospital, Gifu 501‑1194, Japan
| | - Yuka Aoyama
- Department of Biomedical Sciences, College of Life and Health Sciences, Education and Training Center of Medical Technology, Chubu University, Kasugai 487‑8501, Japan
| | - Elsayed Abdelkreem
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu 501‑1194, Japan
| | - Hidenori Ohnishi
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu 501‑1194, Japan
| | | | - Jörn Oliver Sass
- Bioanalytics and Biochemistry, Department of Natural Sciences, University of Applied Sciences, D‑53359 Rheinbach, Germany
| | - Toshiyuki Fukao
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu 501‑1194, Japan
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11
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Abdelkreem E, Otsuka H, Sasai H, Aoyama Y, Hori T, Abd El Aal M, Mahmoud S, Fukao T. Beta-Ketothiolase Deficiency. JOURNAL OF INBORN ERRORS OF METABOLISM AND SCREENING 2016. [DOI: 10.1177/2326409816636644] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Affiliation(s)
- Elsayed Abdelkreem
- Department of Pediatrics, Faculty of Medicine, Sohag University, Sohag, Egypt
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu, Japan
| | - Hiroki Otsuka
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu, Japan
| | - Hideo Sasai
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu, Japan
| | - Yuka Aoyama
- Department of Biomedical Sciences, College of Life and Health Sciences, Education and Training Center of Medical Technology, Chubu University, Kasugai, Japan
| | - Tomohiro Hori
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu, Japan
| | - Mohamed Abd El Aal
- Department of Pediatrics, Faculty of Medicine, Sohag University, Sohag, Egypt
| | - Shaimaa Mahmoud
- Department of Pediatrics, Faculty of Medicine, Sohag University, Sohag, Egypt
| | - Toshiyuki Fukao
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu, Japan
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12
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Nakouzi G, Kreidieh K, Yazbek S. A review of the diverse genetic disorders in the Lebanese population: highlighting the urgency for community genetic services. J Community Genet 2014; 6:83-105. [PMID: 25261319 DOI: 10.1007/s12687-014-0203-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 09/16/2014] [Indexed: 01/19/2023] Open
Abstract
The review lists the genetic diseases reported in Lebanese individuals, surveys genetic programs and services, and highlights the absence of basic genetic health services at the individual and community level. The incidence of individual diseases is not determined, yet the variety of genetic diseases reported is tremendous, most of which follow autosomal recessive inheritance reflecting the social norms in the population, including high rates of consanguinity, which favor the increase in incidence of these diseases. Genetic services including all activities for the diagnosis, care, and prevention of genetic diseases at community level are extremely inadequate. Services are limited to some clinical and laboratory diagnostic services with no genetic counseling. These services are localized within the capital thus preventing their accessibility to high-risk communities. Screening programs, which are at the core of public health prevention services, are minimal and not nationally mandated. The absence of adequate genetic services is attributed to many factors undermining the importance of genetic diseases and their burden on society, the most important of which is genetic illiteracy at all levels of the population, including high-risk families, the general public, and most importantly health care providers and public health officials. Thus, a country like Lebanon, where genetic diseases are expected to be highly prevalent, is in utmost need for community genetics services. Strategies need to be developed to familiarize public health officials and medical professionals with medical genetics leading to a public health infrastructure that delivers community genetics services for the prevention and care of genetic disorders at community level.
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Affiliation(s)
- Ghunwa Nakouzi
- Department of Clinical Pathology, Cleveland Clinic Hospital, Cleveland, OH, USA
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13
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Fukao T, Mitchell G, Sass JO, Hori T, Orii K, Aoyama Y. Ketone body metabolism and its defects. J Inherit Metab Dis 2014; 37:541-51. [PMID: 24706027 DOI: 10.1007/s10545-014-9704-9] [Citation(s) in RCA: 148] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/01/2014] [Revised: 03/01/2014] [Accepted: 03/10/2014] [Indexed: 12/17/2022]
Abstract
Acetoacetate (AcAc) and 3-hydroxybutyrate (3HB), the two main ketone bodies of humans, are important vectors of energy transport from the liver to extrahepatic tissues, especially during fasting, when glucose supply is low. Blood total ketone body (TKB) levels should be evaluated in the context of clinical history, such as fasting time and ketogenic stresses. Blood TKB should also be evaluated in parallel with blood glucose and free fatty acids (FFA). The FFA/TKB ratio is especially useful for evaluation of ketone body metabolism. Defects in ketogenesis include mitochondrial HMG-CoA synthase (mHS) deficiency and HMG-CoA lyase (HL) deficiency. mHS deficiency should be considered in non-ketotic hypoglycemia if a fatty acid beta-oxidation defect is suspected, but cannot be confirmed. Patients with HL deficiency can develop hypoglycemic crises and neurological symptoms even in adolescents and adults. Succinyl-CoA-3-oxoacid CoA transferase (SCOT) deficiency and beta-ketothiolase (T2) deficiency are two defects in ketolysis. Permanent ketosis is pathognomonic for SCOT deficiency. However, patients with "mild" SCOT mutations may have nonketotic periods. T2-deficient patients with "mild" mutations may have normal blood acylcarnitine profiles even in ketoacidotic crises. T2 deficient patients cannot be detected in a reliable manner by newborn screening using acylcarnitines. We review recent data on clinical presentation, metabolite profiles and the course of these diseases in adults, including in pregnancy.
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Affiliation(s)
- Toshiyuki Fukao
- Department of Pediatrics, Graduate School of Medicine, Gifu University, 1-1 Yanagido, Gifu, 501-1194, Japan,
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14
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Shiasi Arani K, Soltani B. First report of 3-oxothiolase deficiency in iran. Int J Endocrinol Metab 2014; 12:e10960. [PMID: 24782902 PMCID: PMC3997948 DOI: 10.5812/ijem.10960] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Revised: 05/18/2013] [Accepted: 07/04/2013] [Indexed: 11/16/2022] Open
Abstract
INTRODUCTION Mitochondrial acetoacetyl-CoA thiolase (3-oxothiolase) deficiency is a rare metabolic disorder involving ketone body metabolism characterized by acute attacks of vomiting, acidosis, ketosis, and lethargy along with some laboratory criteria including excessive excretion of 2-methyl-3-hydroxybutyric acid in urine. CASE PRESENTATION This is a case report of 3-oxothiolase deficiency in a young Iranian boy with presentation of intractable vomiting and severe metabolic acidosis following a common cold in six months of age with abundant urinary 2-methyl-3- hydroxybutyric acid. DISCUSSION This is the first Iranian 3-oxothiolase deficiency case report as searched in the literature. Because of the high rate of consanguineous marriages in Iran, physicians should consider the 3-oxothiolase deficiency in the differential diagnosis of any patient with intractable vomiting and severe metabolic acidosis.
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Affiliation(s)
- Kobra Shiasi Arani
- Research Center for Biochemistry and Nutrition in Metabolic Disorders, Kashan University of Medical Sciences, Kashan, IR Iran
- Corresponding author: Kobra Shiasi Arani, Research Center for Biochemistry and Nutrition in Metabolic Disorders, Kashan University of Medical Sciences, Kashan, IR Iran. Tel: +98-3615550026, E-mail:
| | - Babak Soltani
- Research Center for Biochemistry and Nutrition in Metabolic Disorders, Kashan University of Medical Sciences, Kashan, IR Iran
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15
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Fukao T, Aoyama Y, Murase K, Hori T, Harijan RK, Wierenga RK, Boneh A, Kondo N. Development of MLPA for human ACAT1 gene and identification of a heterozygous Alu-mediated deletion of exons 3 and 4 in a patient with mitochondrial acetoacetyl-CoA thiolase (T2) deficiency. Mol Genet Metab 2013; 110:184-7. [PMID: 23920042 DOI: 10.1016/j.ymgme.2013.07.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Revised: 07/08/2013] [Accepted: 07/08/2013] [Indexed: 01/15/2023]
Abstract
Mitochondrial acetoacetyl-CoA thiolase deficiency is an autosomal recessive disorder, characterized by intermittent ketoacidosis. We developed a multiplex ligation-dependent probe amplification method for mutation detection in the ACAT1 gene, which encodes this enzyme, and validated it using DNAs from two previously reported patients having partial deletion and duplication in this gene. Using this method, we identified a heterozygous deletion including exons 3-4 in a third patient, likely due to Alu-mediated non-equal homologous recombination between Alu sequences.
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Affiliation(s)
- Toshiyuki Fukao
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Yanagido 1-1, Gifu 501-1194, Japan.
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16
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Buhaş D, Bernard G, Fukao T, Décarie JC, Chouinard S, Mitchell GA. A treatable new cause of chorea: beta-ketothiolase deficiency. Mov Disord 2013; 28:1054-6. [PMID: 23818432 DOI: 10.1002/mds.25538] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 02/18/2013] [Accepted: 03/27/2013] [Indexed: 11/09/2022] Open
Affiliation(s)
- Daniela Buhaş
- Department of Medical Genetics, Montreal Children's Hospital, Montréal, Quebéc, Canada
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17
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Fukao T, Maruyama S, Ohura T, Hasegawa Y, Toyoshima M, Haapalainen AM, Kuwada N, Imamura M, Yuasa I, Wierenga RK, Yamaguchi S, Kondo N. Three Japanese Patients with Beta-Ketothiolase Deficiency Who Share a Mutation, c.431A>C (H144P) in ACAT1 : Subtle Abnormality in Urinary Organic Acid Analysis and Blood Acylcarnitine Analysis Using Tandem Mass Spectrometry. JIMD Rep 2011; 3:107-15. [PMID: 23430882 DOI: 10.1007/8904_2011_72] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2010] [Revised: 06/10/2011] [Accepted: 06/20/2011] [Indexed: 02/06/2023] Open
Abstract
Mitochondrial acetoacetyl-CoA thiolase (T2) deficiency affects both isoleucine catabolism and ketone body metabolism. The disorder is characterized by intermittent ketoacidotic episodes. We report three Japanese patients. One patient (GK69) experienced two ketoacidotic episodes at the age of 9 months and 3 years, and no further episodes until the age of 25 years. She had two uncomplicated pregnancies. GK69 was a compound heterozygote of the c.431A>C (H144P) and c.1168T>C (S390P) mutations in T2 (ACAT1) gene. She was not suspected of having T2 deficiency during her childhood, but she was diagnosed as T2 deficient at the age of 25 years by enzyme assay using fibroblasts. The other two patients were identical twin siblings who presented their first ketoacidotic crisis simultaneously at the age of 3 years 4 months. One of them (GK77b) died during the first crisis and the other (GK77) survived. Even during severe crises, C5-OH and C5:1 were within normal ranges in their blood acylcarnitine profiles and trace amounts of tiglylglycine and small amounts of 2-methyl-3-hydroxybutyrate were detected in their urinary organic acid profiles. They were H144P homozygotes. This H144P mutation has retained the highest residual T2 activity in the transient expression analysis of mutant cDNA thus far, while the S390P mutation did not retain any residual T2 activity. The "mild" H144P mutation may result in subtle profiles in blood acylcarnitine and urinary organic acid analyses. T2-deficient patients with "mild" mutations have severe ketoacidotic crises but their chemical phenotypes may be subtle even during acute crises.
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Affiliation(s)
- Toshiyuki Fukao
- Department of Pediatrics, Graduate School of Medicine, Gifu University, 1-1 Yanagido, Gifu, 501-1194, Japan,
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18
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Sarafoglou K, Matern D, Redlinger-Grosse K, Bentler K, Gaviglio A, Harding CO, Rinaldo P. Siblings with mitochondrial acetoacetyl-CoA thiolase deficiency not identified by newborn screening. Pediatrics 2011; 128:e246-50. [PMID: 21669895 DOI: 10.1542/peds.2010-3918] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Screened for by all state newborn screening (NBS) programs in the United States, mitochondrial acetoacetyl-coenzyme A thiolase (T2), or β-ketothiolase, deficiency is a rare autosomal recessive disorder that causes ketoacidosis and hypoglycemia/hyperglycemia. Outcomes vary from normal development to severe cognitive impairment or even death after an acute episode of ketoacidosis. The classical biochemical profile of T2 deficiency is a result of null mutations in both alleles of the ACAT1 gene and consists of persistently increased urinary excretion of ketones, characteristic organic acids, and tiglylglycine as well as abnormal blood or plasma acylcarnitine profiles in acute and stable conditions. Early diagnosis and aggressive management can prevent further episodes of ketoacidosis and lead to normal development. We report the cases of 3 children, all subsequently found to have mutations predicted to be associated with no residual T2 enzymatic activity, but only 1 was identified by NBS in Minnesota since 2001. To our knowledge, this is the first description of compound heterozygotes for null mutations associated with no enzymatic activity exhibiting normal urinary organic acid, blood, and plasma acylcarnitine profiles when clinically well, thereby explaining the false-negative NBS results. We suggest that T2 deficiency may be underrecognized, because the incidence of T2 deficiency in Minnesota, on the basis of these 3 cases, is 1 in 232 000, higher than the reported <1 in 1 million incidence. Our cases emphasize that T2 deficiency must be considered in patients who present with ketoacidosis disproportionately severe to the triggering illness despite normal NBS results or nonspecific biochemical findings in blood and urine during asymptomatic periods.
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Affiliation(s)
- Kyriakie Sarafoglou
- Department of Pediatrics, University of Minnesota Medical School, MMC 8404 13-124 PWB, 516 Delaware St SE, Minneapolis, MN 55455, USA.
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19
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Catanzano F, Ombrone D, Di Stefano C, Rossi A, Nosari N, Scolamiero E, Tandurella I, Frisso G, Parenti G, Ruoppolo M, Andria G, Salvatore F. The first case of mitochondrial acetoacetyl-CoA thiolase deficiency identified by expanded newborn metabolic screening in Italy: the importance of an integrated diagnostic approach. J Inherit Metab Dis 2010; 33 Suppl 3:S91-4. [PMID: 20157782 PMCID: PMC3757262 DOI: 10.1007/s10545-009-9028-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2009] [Revised: 11/19/2009] [Accepted: 12/04/2009] [Indexed: 10/26/2022]
Abstract
A pilot expanded newborn screening programme to detect inherited metabolic disorders by means of liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) began in the Campania region, southern Italy, in 2007. By October 2009, >8,800 dried blood samples on filter paper from 11 hospitals had been screened. Within this screening programme, we identified a case of mitochondrial acetoacetyl-coenzyme A (CoA) thiolase deficiency [β-ketothiolase (β-KT) deficiency] by analysing the acylcarnitine profile from a dried blood spot with LC-MS/MS. Gas chromatography coupled with mass spectrometry analysis of urinary organic acids and LC-MS/MS analysis of urinary acylcarnitines were in line with this disorder. In fact, concentrations were well beyond the cut-off values of tiglyl carnitine, 3-hydroxybutyrylcarnitine and 2-methyl-3-hydroxybutyrylcarnitine, 2-methyl-3-hydroxybutyric acid and tiglyl glycine. The absence of 2-methylacetoacetic acid in urine may be attributed to: (i) the instability of this β-ketoacid because it undergoes spontaneous decarboxylation to 2-butanone, which is highly volatile and thus difficult to detect, and (ii) the good health of the patient in the first days of life. β-KT deficiency was subsequently diagnosed in the patient's older sister, who showed increased levels of the same metabolites but also small amounts of 2-methylacetoacetic acid, which is considered a key marker for β-KT diagnosis. Genomic analysis revealed mutation c.1189C >G in exon 12 of the ACAT1 gene, which results in a severe defect because of the p.H397D amino acid change in both alleles of both patients.
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Affiliation(s)
- Francesca Catanzano
- CEINGE–Biotecnologie Avanzate, Napoli, Dipartimento di Scienze Biologiche ed Ambientali, Università del Sannio, Benevento, Naples, Italy
| | - Daniela Ombrone
- CEINGE–Biotecnologie Avanzate, Napoli, Dipartimento di Biochimica e Biotecnologie Mediche, Università degli Studi di Napoli “Federico II”, Via Comunale Margherita 482, 80145 Naples, Italy
| | | | - Anna Rossi
- Ospedale San Luca, Vallo della Lucania, Salerno, Italy
| | | | - Emanuela Scolamiero
- CEINGE–Biotecnologie Avanzate, Napoli, Dipartimento di Biochimica e Biotecnologie Mediche, Università degli Studi di Napoli “Federico II”, Via Comunale Margherita 482, 80145 Naples, Italy
| | - Igor Tandurella
- CEINGE–Biotecnologie Avanzate, Napoli, Dipartimento di Biochimica e Biotecnologie Mediche, Università degli Studi di Napoli “Federico II”, Via Comunale Margherita 482, 80145 Naples, Italy
| | - Giulia Frisso
- CEINGE–Biotecnologie Avanzate, Napoli, Dipartimento di Biochimica e Biotecnologie Mediche, Università degli Studi di Napoli “Federico II”, Via Comunale Margherita 482, 80145 Naples, Italy
| | - Giancarlo Parenti
- Dipartimento di Pediatria, Università degli Studi di Napoli “Federico II”, Naples, Italy
| | - Margherita Ruoppolo
- CEINGE–Biotecnologie Avanzate, Napoli, Dipartimento di Biochimica e Biotecnologie Mediche, Università degli Studi di Napoli “Federico II”, Via Comunale Margherita 482, 80145 Naples, Italy
| | - Generoso Andria
- Dipartimento di Pediatria, Università degli Studi di Napoli “Federico II”, Naples, Italy
| | - Francesco Salvatore
- CEINGE – Biotecnologie Avanzate, Via S. Pansini 5, 80131 Naples, Italy
- IRCCS – Fondazione SDN, Via Crispi 8, Naples, Italy
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20
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Fukao T, Horikawa R, Naiki Y, Tanaka T, Takayanagi M, Yamaguchi S, Kondo N. A novel mutation (c.951C>T) in an exonic splicing enhancer results in exon 10 skipping in the human mitochondrial acetoacetyl-CoA thiolase gene. Mol Genet Metab 2010; 100:339-44. [PMID: 20488739 DOI: 10.1016/j.ymgme.2010.03.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2010] [Revised: 03/16/2010] [Accepted: 03/16/2010] [Indexed: 12/25/2022]
Abstract
Mitochondrial acetoacetyl-CoA thiolase (T2) deficiency is an inherited disorder affecting isoleucine catabolism and ketone body metabolism. A Japanese female developed a severe ketoacidotic attack at the age of 7 months. Urinary organic acid analysis showed elevated excretion of 2-methyl-3-hydroxybutyrate but not tiglylglycine. She was diagnosed as having T2 deficiency by enzyme assay using fibroblasts. Mutation analysis revealed a compound heterozygote of c.556G>T(D186Y) and c.951C>T(D317D). Since c.951C>T does not cause amino acid change, we performed cDNA analysis and found that exon 10 skipping had occurred in the c.951C>T allele. A computer search using an ESE finder showed that an exonic splicing enhancer sequence, SF2/ASF, was located in CTGA(951)CGC. We hypothesized that the exonic splicing enhancer is necessary for accurate splicing since the first nucleotide of exon 10 is C, which weakens the splice acceptor site of intron 9. We made a mini gene construct including exon 9-truncated intron 9-exon 10-truncated intron 10-exon 11 for a splicing experiment. We also made three mutant constructs which alter the SF2/ASF site (947C>T, 951C>T, 952G>A). An min-gene splicing experiment clearly showed that exon 10 skipping was induced in all three mutant constructs. Moreover, additional substitution of G for C at the first nucleotide of exon 10 resulted in normal splicing in these three mutants. These results confirmed that c.951C>T diminished the effect of the exonic splicing enhancer and caused exon 10 skipping.
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Affiliation(s)
- Toshiyuki Fukao
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu 501-1194, Japan.
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21
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Fukao T, Nguyen HT, Nguyen NT, Vu DC, Can NTB, Pham ATV, Nguyen KN, Kobayashi H, Hasegawa Y, Bui TP, Niezen-Koning KE, Wanders RJA, de Koning T, Nguyen LT, Yamaguchi S, Kondo N. A common mutation, R208X, identified in Vietnamese patients with mitochondrial acetoacetyl-CoA thiolase (T2) deficiency. Mol Genet Metab 2010; 100:37-41. [PMID: 20156697 DOI: 10.1016/j.ymgme.2010.01.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2009] [Revised: 01/15/2010] [Accepted: 01/15/2010] [Indexed: 10/19/2022]
Abstract
Mitochondrial acetoacetyl-CoA thiolase (T2) deficiency is an inborn error of metabolism affecting isoleucine catabolism and ketone body utilization. This disorder is clinically characterized by intermittent ketoacidotic episodes with no clinical symptoms between episodes. In general, T2 gene mutations are heterogeneous. No common mutations have been identified and more than 70 mutations have been identified in 70 patients with T2 deficiency (including unpublished data). We herein identified a common mutation, R208X, in Vietnamese patients. We identified R208X homozygously in six patients and heterozygously in two patients among eight Vietnamese patients. This R208X mutation was also identified heterozygously in two Dutch patients, however, R208X mutant alleles in the Vietnamese have a different haplotype from that in the Dutch, when analyzed using Msp I and Taq I polymorphisms in the T2 gene. The R208X mutant allele was not so frequent in the Vietnamese since we could not find that mutant allele in 400 healthy Vietnamese controls using the Nla III restriction enzyme assay. DNA diagnosis of T2 deficiency may be applicable to the Vietnamese population.
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Affiliation(s)
- Toshiyuki Fukao
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu 501-1194, Japan.
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22
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Thümmler S, Dupont D, Acquaviva C, Fukao T, de Ricaud D. Different clinical presentation in siblings with mitochondrial acetoacetyl-CoA thiolase deficiency and identification of two novel mutations. TOHOKU J EXP MED 2010; 220:27-31. [PMID: 20046049 DOI: 10.1620/tjem.220.27] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Mitochondrial acetoacetyl-CoA thiolase (T2) catalyzes 2-methylacetoacetyl-CoA cleavage into acetyl-CoA and propionyl-CoA in isoleucine catabolism and interconversion between acetyl-CoA and acetoacetyl-CoA in ketone body metabolism. T2 deficiency is a rare metabolic disease of autosomal recessive inheritance. The disorder is characterized by intermittent ketoacidotic episodes. The onset of clinical symptoms is in the infant or toddler period. The frequency of episodes declines with age, stopping before adolescence. Here we report two siblings with this disorder. The proband (GK65) is a French girl born from non-consanguineous parents. She presented several ketoacidotic episodes with 5 hospitalizations from age 2 to 4 years, the first of them complicated by ketoacidotic coma. Minor episodes, which are generally provoked by infections or high protein intake, still persist at age of 16 years. Molecular analysis of the T2 gene has revealed the compound heterozygosity of c.578T>C (M193T) and IVS8+5g>t. The latter mutation results in skipping of exon 8. In contrast, the younger brother (GK65b) had a unique ketoacidotic crisis at the age of 6 years that is the oldest-age first crisis among T2-deficient patients reported thus far. Despite the mild phenotype, he carried the same T2 gene mutations as his sister (GK65). Furthermore, T2 catalytic activity and T2 protein were not detected in the fibroblasts derived from GK65 and GK65b. In conclusion, the siblings with the same T2 gene mutations present different clinical severity. Diagnostic testing for asymptomatic siblings is important in the management of T2-deficient families.
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23
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Fukao T, Boneh A, Aoki Y, Kondo N. A novel single-base substitution (c.1124A>G) that activates a 5-base upstream cryptic splice donor site within exon 11 in the human mitochondrial acetoacetyl-CoA thiolase gene. Mol Genet Metab 2008; 94:417-421. [PMID: 18511318 DOI: 10.1016/j.ymgme.2008.04.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2008] [Revised: 04/17/2008] [Accepted: 04/17/2008] [Indexed: 10/22/2022]
Abstract
Most mutations related to aberrant splicing occur in conserved splice acceptor and donor sites. Some exonic mutations also affect splicing. We identified and characterized a point mutation (c.1124A>G) in an Australian patient (GK43) with mitochondrial acetoacetyl-CoA thiolase (T2) deficiency. GK43 is a homozygote of c.1124A>G, which activates a cryptic splice donor site 5 bases upstream from c.1124A>G within exon 11, causing aberrant splicing in most transcripts. The aberrant splicing results in c.1120-1163 (44-base) deletion, causing a frameshift in T2 mRNA. A mini-gene splicing experiment confirmed that the c.1124A>G substitution was responsible for this aberrant splicing. This cryptic splice site has a Shapiro and Senapathy score (70.0) in a normal sequence but if mutated, the score (84.3) becomes higher than the one in the authentic splice donor site of intron 11 (81.4). This is an example in which a point mutation activates a cryptic splice donor site motif that is used preferentially over a downstream authentic splice site.
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Affiliation(s)
- Toshiyuki Fukao
- Department of Pediatrics, Graduate School of Medicine, Gifu University, 1-1 Yanagido, Gifu 501-1194, Japan; Division of Medical Information Sciences, United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, Gifu 501-1194, Japan
| | - Avihu Boneh
- Metabolic Service, Murdoch Childrens Research Institute, Royal Children's Hospital, Department of Paediatrics, University of Melbourne, Australia
| | - Yusuke Aoki
- Department of Pediatrics, Graduate School of Medicine, Gifu University, 1-1 Yanagido, Gifu 501-1194, Japan
| | - Naomi Kondo
- Department of Pediatrics, Graduate School of Medicine, Gifu University, 1-1 Yanagido, Gifu 501-1194, Japan
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24
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Fukao T, Zhang G, Rolland MO, Zabot MT, Guffon N, Aoki Y, Kondo N. Identification of an Alu-mediated tandem duplication of exons 8 and 9 in a patient with mitochondrial acetoacetyl-CoA thiolase (T2) deficiency. Mol Genet Metab 2007; 92:375-8. [PMID: 17719254 DOI: 10.1016/j.ymgme.2007.07.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2007] [Revised: 07/10/2007] [Accepted: 07/10/2007] [Indexed: 02/04/2023]
Abstract
A tandem repeat of exons 8 and 9 was identified in the cDNA for mitochondrial acetoacetyl-CoA thiolase (T2) in a typical T2 deficient patient. Routine mutation analysis using PCR at the genomic level had failed to identify any mutations. Alu element-mediated unequal homologous recombination between an Alu-Jo in intron 7 and another Alu-Jo in intron 9 appears to be responsible for this duplication.
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Affiliation(s)
- Toshiyuki Fukao
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Yanagido 1-1, Gifu 501-1194, Japan.
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25
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Sakurai S, Fukao T, Haapalainen AM, Zhang G, Yamada K, Lilliu F, Yano S, Robinson P, Gibson MK, Wanders RJA, Mitchell GA, Wierenga RK, Kondo N. Kinetic and expression analyses of seven novel mutations in mitochondrial acetoacetyl-CoA thiolase (T2): identification of a Km mutant and an analysis of the mutational sites in the structure. Mol Genet Metab 2007; 90:370-8. [PMID: 17236799 DOI: 10.1016/j.ymgme.2006.12.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2006] [Revised: 12/03/2006] [Accepted: 12/03/2006] [Indexed: 11/19/2022]
Abstract
Mitochondrial acetoacetyl-CoA thiolase (T2) deficiency is an inborn error of metabolism that affects isoleucine catabolism and ketone body metabolism. We identified 7 novel and 2 previously reported mutations in six T2-deficient patients. Transient expression analysis of wild-type and eight mutant cDNAs was performed at 40, 37 and 30 degrees C. Although no significant residual activity was detected, mutant proteins were detected in the N158D, N158S, R208Q, Y219H and N282H mutants. Accumulation of these mutant proteins was temperature-sensitive with the highest expression levels at lower temperatures. Expression of Q73P and N353K cDNAs yielded neither residual T2 protein nor enzyme activity. An E252del mutant T2 was detected with a relative protein amount and enzyme activity of 30% and 25%, respectively, in comparison to the wild-type at 37 degrees C. The E252del mutant protein was more stable at 30 degrees C expression than 37 degrees C, but was essentially undetectable at 40 degrees C, indicating its temperature-sensitive instability. Kinetic studies revealed a twofold K(m) elevation for substrates coenzyme A and acetoacetyl-CoA in the E252del mutant, while V(max) was comparable to the wild-type. We conclude that the E252del is a temperature-sensitive K(m) mutant. This correlates well with the effect predicted from the T2 tertiary structure analysis, using the crystal structure of the human T2 homotetramer. The probable effect of the other mutations on the T2 tertiary structure was also evaluated.
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Affiliation(s)
- Satomi Sakurai
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu, Gifu, Japan
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Korman SH. Inborn errors of isoleucine degradation: a review. Mol Genet Metab 2006; 89:289-99. [PMID: 16950638 DOI: 10.1016/j.ymgme.2006.07.010] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2006] [Revised: 07/27/2006] [Accepted: 07/27/2006] [Indexed: 11/28/2022]
Abstract
Three inborn errors have been identified in the pathway of isoleucine degradation. Deficiency of beta-ketothiolase (beta-KT, also known as T2, mitochondrial acetoacetyl-CoA thiolase and acetyl-CoA acetyltransferase 1) is a well-described disorder which presents with acute episodic ketoacidosis. In contrast, short/branched-chain acyl-CoA dehydrogenase (SBCAD) and 2-methyl-3-hydroxybutyryl-CoA dehydrogenase (MHBD) deficiencies are recently described and relatively rare defects which present with predominantly neurological manifestations, although acute metabolic decompensation may occur in the early newborn period. Careful examination of urine organic acids is required for identification and differential diagnosis of these disorders, with awareness that the abnormalities may be subtle and variable. Tandem MS analysis of acylcarnitines may reveal elevated C5 (SBCAD) or C5:1 and/or OH-C5 species (MHBD and beta-KT deficiencies) but the abnormalities are non-diagnostic and may be intermittent or absent. Confirmation of diagnosis is therefore advisable by specific enzyme assay and/or mutation analysis of the ACAT1 (beta-KT), ACADSB (SBCAD) or HADH2 (MHBD) genes. The latter is located on the X chromosome, accounting for the milder clinical phenotype in females. If beta-KT deficiency is diagnosed early and treated by fasting avoidance and modest protein restriction, ketoacidosis episodes can be prevented and the prognosis is excellent. The role of treatment in SBCAD deficiency remains unclear pending further delineation of its clinical phenotype and pathogenicity, particularly regarding asymptomatic individuals detected by expanded newborn screening. The ineffectiveness of isoleucine restriction in MHBD deficiency is consistent with the additional roles of this multifunctional enzyme in sex steroid and neurosteroid metabolism and its interaction with amyloid-beta peptide.
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Affiliation(s)
- Stanley H Korman
- Metabolic Diseases Unit, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel.
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Zhang G, Fukao T, Sakurai S, Yamada K, Michael Gibson K, Kondo N. Identification of Alu-mediated, large deletion-spanning exons 2-4 in a patient with mitochondrial acetoacetyl-CoA thiolase deficiency. Mol Genet Metab 2006; 89:222-6. [PMID: 16935016 DOI: 10.1016/j.ymgme.2006.06.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2006] [Revised: 06/19/2006] [Accepted: 06/19/2006] [Indexed: 10/24/2022]
Abstract
Mitochondrial acetoacetyl-CoA thiolase (T2) deficiency is a rare inherited metabolic disorder affecting isoleucine catabolism and ketone body metabolism. So far, more than 39 different mutations have been identified in 60 T2-deficient patients. However, no large deletions have been reported. We herein report the first case of a large T2 gene deletion from intron 1 to intron 4 in a T2-deficient patient (GK41). cDNA analysis revealed that an aberrant cDNA with exons 2-5 skipping was a major transcript, associated with a minor transcript of exons 2-4 skipping with a 94-bp insertion composed of an intron 1 sequence. Genomic analysis indicated an absence of PCR amplification of exons 2-4 and gene deletion was revealed by Southern blot analysis. Cloning and sequencing long range PCR products revealed a 6.4kb deletion. Alu element-mediated unequal homologous recombination between an Alu-Sx in intron 1 and another Alu-Y in intron 4 appears to be responsible for this deletion.
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Affiliation(s)
- Gaixiu Zhang
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu, Gifu 501-1194, Japan
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Pasquali M, Monsen G, Richardson L, Alston M, Longo N. Biochemical findings in common inborn errors of metabolism. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2006; 142C:64-76. [PMID: 16602099 DOI: 10.1002/ajmg.c.30086] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The application of tandem mass spectrometry (MS/MS) to newborn screening has led to the detection of patients with a wider spectrum of inborn errors of metabolism. A definitive diagnosis can often be established early enough to start treatment before symptoms appear. Here, we review common biochemical findings in disorders caused by deficiency of 3-methylcrotonyl-CoA carboxylase, isobutyryl-CoA dehydrogenase, 2-methyl-3-hydroxybutyryl-CoA dehydrogenase, 3-ketothiolase, 2-methylbutyryl-CoA dehydrogenase, and medium chain acyl CoA dehydrogenase. The diagnosis of these disorders requires biochemical confirmation by measurement of plasma acylcarnitine profile, urine organic acids, and urine acylglycine profiles followed by measurement of enzyme activity or detection of causative mutations. Early treatment can improve the outcome of these disorders.
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Affiliation(s)
- Marzia Pasquali
- University of Utah, and ARUP Laboratories, 500 Chipeta Way, Salt Lake City, UT 84108, USA.
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