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Tajima G, Hara K, Tsumura M, Kagawa R, Sakura F, Sasai H, Yuasa M, Shigematsu Y, Okada S. Newborn Screening with (C16 + C18:1)/C2 and C14/C3 for Carnitine Palmitoyltransferase II Deficiency throughout Japan Has Revealed C12/C0 as an Index of Higher Sensitivity and Specificity. Int J Neonatal Screen 2023; 9:62. [PMID: 37987475 PMCID: PMC10660675 DOI: 10.3390/ijns9040062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 10/19/2023] [Accepted: 10/25/2023] [Indexed: 11/22/2023] Open
Abstract
Carnitine palmitoyltransferase (CPT) II deficiency is a long-chain fatty acid oxidation disorder. It manifests as (1) a lethal neonatal form, (2) a hypoglycemic form, or (3) a myopathic form. The second form can cause sudden infant death and is more common among Japanese people than in other ethnic groups. Our study group had earlier used (C16 + C18:1)/C2 to conduct a pilot newborn screening (NBS) study, and found that the use of C14/C3 for screening yielded lower rates of false positivity; in 2018, as a result, nationwide NBS for CPT II deficiency started. In this study, we evaluated the utility of these ratios in 71 NBS-positive infants and found that the levels of both C14/C3 and (C16 + C18:1)/C2 in patients overlapped greatly with those of infants without the disease. Among the levels of acylcarnitines with various chain lengths (C18 to C2) and levels of free carnitine (C0) as well as their ratios of various patterns, C12/C0 appeared to be a promising index that could reduce false-positive results without missing true-positive cases detected by current indices. Although some cases of the myopathic form may go undetected even with C12/C0, its use will help prevent life-threatening onset of the hypoglycemic form of CPT II deficiency.
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Affiliation(s)
- Go Tajima
- Division of Neonatal Screening, Research Institute, National Center for Child Health and Development, 2-10-1 Okura, Setagaya-ku, Tokyo 157-8535, Japan
- Department of Pediatrics, Hiroshima University Graduate School of Biomedical and Health Sciences, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan; (K.H.); (M.T.); (R.K.); (F.S.); (S.O.)
| | - Keiichi Hara
- Department of Pediatrics, Hiroshima University Graduate School of Biomedical and Health Sciences, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan; (K.H.); (M.T.); (R.K.); (F.S.); (S.O.)
- Department of Pediatrics, National Hospital Organization Kure Medical Center and Chugoku Cancer Center, 3-1 Aoyama-cho, Kure 737-0023, Japan
| | - Miyuki Tsumura
- Department of Pediatrics, Hiroshima University Graduate School of Biomedical and Health Sciences, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan; (K.H.); (M.T.); (R.K.); (F.S.); (S.O.)
| | - Reiko Kagawa
- Department of Pediatrics, Hiroshima University Graduate School of Biomedical and Health Sciences, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan; (K.H.); (M.T.); (R.K.); (F.S.); (S.O.)
| | - Fumiaki Sakura
- Department of Pediatrics, Hiroshima University Graduate School of Biomedical and Health Sciences, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan; (K.H.); (M.T.); (R.K.); (F.S.); (S.O.)
- Department of Technology Development, Kazusa DNA Research Institute, Kisarazu 292-0818, Japan
| | - Hideo Sasai
- Department of Early Diagnosis and Preventive Medicine for Rare Intractable Pediatric Diseases, Graduate School of Medicine, Gifu University, 1-1 Yanagido, Gifu 501-1194, Japan;
| | - Miori Yuasa
- Department of Pediatrics, Faculty of Medical Sciences, University of Fukui, 23-3 Matsuoka-Shimoaizuki, Eiheiji-cho, Fukui 910-1193, Japan; (M.Y.); (Y.S.)
| | - Yosuke Shigematsu
- Department of Pediatrics, Faculty of Medical Sciences, University of Fukui, 23-3 Matsuoka-Shimoaizuki, Eiheiji-cho, Fukui 910-1193, Japan; (M.Y.); (Y.S.)
| | - Satoshi Okada
- Department of Pediatrics, Hiroshima University Graduate School of Biomedical and Health Sciences, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan; (K.H.); (M.T.); (R.K.); (F.S.); (S.O.)
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Zhou D, Cheng Y, Yin X, Miao H, Hu Z, Yang J, Zhang Y, Wu B, Huang X. Newborn Screening for Mitochondrial Carnitine-Acylcarnitine Cycle Disorders in Zhejiang Province, China. Front Genet 2022; 13:823687. [PMID: 35360862 PMCID: PMC8964036 DOI: 10.3389/fgene.2022.823687] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Accepted: 01/20/2022] [Indexed: 11/18/2022] Open
Abstract
Background: Disorders of mitochondrial carnitine–acylcarnitine cycle is a heterogeneous group of hereditary diseases of mitochondrial β-oxidation of fatty acids tested in NBS program in Zhejiang province, China. Large-scale studies reporting disorders of mitochondrial carnitine–acylcarnitine cycle among Chinese population in NBS are limited. The aim of this study was to explain the incidence and biochemical, clinical, and genetic characteristics of disorders of mitochondrial carnitine–acylcarnitine cycle in NBS. Methods: From January 2009 to June 2021, 4,070,375 newborns were screened by tandem mass spectrometry. Newborns with elevated C0 levels and/or C0/(C16 + C18) ratios were identified as having CPT1D, whereas those with decreased C0 levels and/or C0/(C16 + C18) ratios and/or elevated C12-C18:1 level were identified as having CPT2D or CACTD. Suspected positive patients were further subjected to genetic analysis. All confirmed patients received biochemical and nutritional treatment, as well as follow-up sessions. Results: Overall, 20 patients (12 with CPT1D, 4 with CPT2D, and 4 with CACTD) with disorders of mitochondrial carnitine–acylcarnitine cycle were diagnosed by NBS. The overall incidence of these disorders was one in 203,518 newborns. In toal, 11 patients with CPT1D exhibited increased C0 levels and C0/(C16 + C18) ratios. In all patients of CPT2D, all long chain acyl-carnitines levels were elevated except for case 14 having normal C12 levels. In all patients with CACTD, all long chain acyl-carnitines levels were elevated except for case 17 having normal C12, C18, and C18:1 levels. Most patients with CPT1D were asymptomatic. Overall, two of 4 patients with CPT2D did not present any clinical symptom, but other two patients died. In 4 cases with CACTD, the disease was onset after birth, and 75% patients died. In total, 14 distinct mutations were identified in CPT1A gene, of which 11 were novel and c.1910C > A (p.S637T), c.740C > T (p.P247L), and c.1328T > C (p.L443P) were the most common mutations. Overall, 3 novel mutations were identified in CPT2 gene, and the most frequent mutation was c.1711C > A (p.P571T). The most common variant in SLC25A20 gene was c.199-10T > G. Conclusion: Disorders of mitochondrial carnitine–acylcarnitine cycle can be detected by NBS, and the combined incidence of these disorders in newborns was rare in Zhejiang province, China. Most patients presented typical acylcarnitine profiles. Most patients with CPT1D presented normal growth and development, whereas those with CPT2D/CACTD exhibited a high mortality rate. Several novel CPT1A and CPT2 variants were identified, which expanded the variant spectrum.
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Affiliation(s)
- Duo Zhou
- Department of Genetics and Metabolism, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, National Regional Medical Center for Children, Hangzhou, China
| | - Yi Cheng
- Department of Genetics and Metabolism, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, National Regional Medical Center for Children, Hangzhou, China
| | - Xiaoshan Yin
- School of Health in Social Science, The University of Edinburg, Edinburg, United Kingdom
| | - Haixia Miao
- Department of Genetics and Metabolism, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, National Regional Medical Center for Children, Hangzhou, China
| | - Zhenzhen Hu
- Department of Genetics and Metabolism, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, National Regional Medical Center for Children, Hangzhou, China
| | - Jianbin Yang
- Department of Genetics and Metabolism, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, National Regional Medical Center for Children, Hangzhou, China
| | - Yu Zhang
- Zhejiang Bosheng Biotechnology Co, Ltd, Hangzhou, China
| | - Benqing Wu
- Children's Medical Center, University of Chinese Academy of Science - Shenzhen Hospital, Shenzhen, China
| | - Xinwen Huang
- Department of Genetics and Metabolism, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, National Regional Medical Center for Children, Hangzhou, China
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Shelihan I, Rossignol E, Décarie J, Bonnefont J, Brivet M, Brunel‐Guitton C, Mitchell GA. Infantile onset carnitine palmitoyltransferase 2 deficiency: Cortical polymicrogyria, schizencephaly, and gray matter heterotopias in an adolescent with normal development. JIMD Rep 2022; 63:3-10. [PMID: 35028265 PMCID: PMC8743346 DOI: 10.1002/jmd2.12243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 06/21/2021] [Accepted: 07/19/2021] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE To report an adolescent with infantile-onset carnitine palmitoyltransferase 2 (CPT2) deficiency and cerebral malformations and to review the occurrence of brain malformations in CPT2 deficiency. The patient presented clinically at age 5 months with dehydration and hepatomegaly. He also has an unrelated condition, X-linked nephrogenic diabetes insipidus. He had recurrent rhabdomyolysis but normal psychomotor development. At age 17 years, he developed spontaneous focal seizures. Cerebral magnetic resonance imaging revealed extensive left temporo-parieto-occipital polymicrogyria, white matter heterotopias, and schizencephaly. Neuronal migration defects were previously reported in lethal neonatal CPT2 deficiency but not in later-onset forms. DESIGN AND METHODS We searched PubMed, Google Scholar, and the bibliographies of the articles found by these searches, for cerebral malformations in CPT2 deficiency. All antenatal, neonatal, infantile, and adult-onset cases were included. Exclusion criteria included insufficient information about age of clinical onset and lack of confirmation of CPT2 deficiency by enzymatic assay or genetic testing. For each report, we noted the presence of cerebral malformations on brain imaging or pathological examination. RESULTS Of 26 neonatal-onset CPT2-deficient patients who met the inclusion criteria, brain malformations were reported in 16 (61.5%). In 19 infantile-onset cases, brain malformations were not reported, but only 3 of the 19 reports (15.8%) include brain imaging or neuropathology data. In 276 adult-onset cases, no brain malformations were reported. CONCLUSION To the best of our knowledge, this is the first report of cerebral malformations in an infantile onset CPT2-deficient patient. Brain imaging should be considered in patients with CPTII deficiency and neurological manifestations, even in those with later clinical onset.
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Affiliation(s)
- Ivan Shelihan
- Divisions of Medical Genetics (IS, CBG, GM) and Neurology (ER), Department of PediatricsCHU Sainte‐Justine and Université de MontréalMontrealQuebecCanada
| | - Elsa Rossignol
- Divisions of Medical Genetics (IS, CBG, GM) and Neurology (ER), Department of PediatricsCHU Sainte‐Justine and Université de MontréalMontrealQuebecCanada
- Department of NeurosciencesCHU Sainte‐Justine and Université de MontréalMontreal, QCQuebecCanada
| | - Jean‐Claude Décarie
- Department of Medical ImagingCHU Sainte‐Justine and Université de MontréalMontrealQuebecCanada
| | - Jean‐Paul Bonnefont
- Medical Genetics FederationNecker Enfants Malades Hospital and IMAGINE InstituteParisFrance
| | - Michèle Brivet
- Medical Genetics FederationNecker Enfants Malades Hospital and IMAGINE InstituteParisFrance
| | - Catherine Brunel‐Guitton
- Biochemical Diseases, Department of Pediatrics, Faculty of MedicineUniversity of British Columbia, BC Children's HospitalVancouverBritishColumbia
| | - Grant A. Mitchell
- Divisions of Medical Genetics (IS, CBG, GM) and Neurology (ER), Department of PediatricsCHU Sainte‐Justine and Université de MontréalMontrealQuebecCanada
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Meinhardt B, Motlagh Scholle L, Seifert F, Anwand M, Pietzsch M, Zierz S. Cardiolipin Stabilizes and Increases Catalytic Efficiency of Carnitine Palmitoyltransferase II and Its Variants S113L, P50H, and Y479F. Int J Mol Sci 2021; 22:4831. [PMID: 34063237 PMCID: PMC8125234 DOI: 10.3390/ijms22094831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 04/28/2021] [Accepted: 04/29/2021] [Indexed: 11/29/2022] Open
Abstract
Muscle carnitine palmitoyltransferase II (CPT II) deficiency is associated with various mutations in CPT2 gene. In the present study, the impact of the two CPT II variants P50H and Y479F were characterized in terms of stability and activity in vitro in comparison to wildtype (WT) and the well investigated variant S113L. While the initial enzyme activity of all variants showed wild-type-like behavior, the activity half-lives of the variants at different temperatures were severely reduced. This finding was validated by the investigation of thermostability of the enzymes using nano differential scanning fluorimetry (nanoDSF). Further, it was studied whether the protein stabilizing diphosphatidylglycerol cardiolipin (CL) has an effect on the variants. CL indeed had a positive effect on the stability. This effect was strongest for WT and least pronounced for variant P50H. Additionally, CL improved the catalytic efficiency for CPT II WT and the investigated variants by twofold when carnitine was the varied substrate due to a decrease in KM. However, there was no influence detected for the variation of substrate palmitoyl-CoA. The functional consequences of the stabilization by CL in vivo remain open.
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Affiliation(s)
- Beate Meinhardt
- Department of Neurology, Martin-Luther-University Halle-Wittenberg, Ernst-Grube-Str. 40, 06120 Halle (Saale), Germany; (L.M.S.); (S.Z.)
| | - Leila Motlagh Scholle
- Department of Neurology, Martin-Luther-University Halle-Wittenberg, Ernst-Grube-Str. 40, 06120 Halle (Saale), Germany; (L.M.S.); (S.Z.)
| | - Franziska Seifert
- Department of Pharmaceutical Technology and Biopharmacy, Institute of Pharmacy, Martin-Luther-University Halle-Wittenberg, Weinbergweg 22, 06120 Halle (Saale), Germany; (F.S.); (M.A.); (M.P.)
| | - Martina Anwand
- Department of Pharmaceutical Technology and Biopharmacy, Institute of Pharmacy, Martin-Luther-University Halle-Wittenberg, Weinbergweg 22, 06120 Halle (Saale), Germany; (F.S.); (M.A.); (M.P.)
| | - Markus Pietzsch
- Department of Pharmaceutical Technology and Biopharmacy, Institute of Pharmacy, Martin-Luther-University Halle-Wittenberg, Weinbergweg 22, 06120 Halle (Saale), Germany; (F.S.); (M.A.); (M.P.)
| | - Stephan Zierz
- Department of Neurology, Martin-Luther-University Halle-Wittenberg, Ernst-Grube-Str. 40, 06120 Halle (Saale), Germany; (L.M.S.); (S.Z.)
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Bo R, Musha I, Yamada K, Kobayashi H, Hasegawa Y, Awano H, Arao M, Kikuchi T, Taketani T, Ohtake A, Yamaguchi S, Iijima K. Need for strict clinical management of patients with carnitine palmitoyltransferase II deficiency: Experience with two cases detected by expanded newborn screening. Mol Genet Metab Rep 2020; 24:100611. [PMID: 32489884 PMCID: PMC7260588 DOI: 10.1016/j.ymgmr.2020.100611] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 05/21/2020] [Accepted: 05/22/2020] [Indexed: 12/31/2022] Open
Abstract
In Japan, carnitine palmitoyltransferase II (CPTII) deficiency has been included as one of the primary target diseases in the expanded newborn mass screening program since 2018. However, many cases of the severe infantile hepatocardiomuscular form of CPTII deficiency showed severe neurodevelopmental delay or sudden death, which indicated that management of CPTII deficiency in the acute phase remains to be studied in detail. Herein, we discuss two cases diagnosed by newborn mass screening. Patient 1 was under strict clinical management from the neonatal period, with >20 admissions in 14 months, while Patient 2 was managed using a relatively relaxed approach, with only 2 admissions in the same period. Patient 1 showed normal development; however, Patient 2 expired at the age of 1 year 2 months. To develop strategies for preventing sudden deaths in patients with CPTII deficiency, this retrospective study focused on detailed clinical management practices and biochemical findings during the acute phase. We also investigated the correlation between conventional biomarkers (such as creatine kinase) and long-chain acylcarnitines. We propose that strict monitoring and immediate medical attention, even in case of slight fever or minor abdominal symptoms, can help prevent sudden death in patients with CPTII deficiency. Considering the higher morbidity rate of such patients, strict and acute management of CPTII deficiency cannot be overemphasized.
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Affiliation(s)
- Ryosuke Bo
- Department of Pediatrics, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.,Department of Pediatrics, Shimane University Faculty of Medicine, 89-1 En-ya-cho, Izumo 693-8501, Japan
| | - Ikuma Musha
- Department of Pediatrics, Faculty of Medicine, Saitama Medical University, 38 Morohongo, Moroyama-cho, Saitama 350-0495, Japan
| | - Kenji Yamada
- Department of Pediatrics, Shimane University Faculty of Medicine, 89-1 En-ya-cho, Izumo 693-8501, Japan
| | - Hironori Kobayashi
- Department of Pediatrics, Shimane University Faculty of Medicine, 89-1 En-ya-cho, Izumo 693-8501, Japan
| | - Yuki Hasegawa
- Department of Pediatrics, Shimane University Faculty of Medicine, 89-1 En-ya-cho, Izumo 693-8501, Japan
| | - Hiroyuki Awano
- Department of Pediatrics, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan
| | - Masato Arao
- Department of Pediatrics, Faculty of Medicine, Saitama Medical University, 38 Morohongo, Moroyama-cho, Saitama 350-0495, Japan
| | - Toru Kikuchi
- Department of Pediatrics, Faculty of Medicine, Saitama Medical University, 38 Morohongo, Moroyama-cho, Saitama 350-0495, Japan
| | - Takeshi Taketani
- Department of Pediatrics, Shimane University Faculty of Medicine, 89-1 En-ya-cho, Izumo 693-8501, Japan
| | - Akira Ohtake
- Department of Pediatrics, Faculty of Medicine, Saitama Medical University, 38 Morohongo, Moroyama-cho, Saitama 350-0495, Japan
| | - Seiji Yamaguchi
- Department of Pediatrics, Shimane University Faculty of Medicine, 89-1 En-ya-cho, Izumo 693-8501, Japan
| | - Kazumoto Iijima
- Department of Pediatrics, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan
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Joshi PR, Zierz S. Muscle Carnitine Palmitoyltransferase II (CPT II) Deficiency: A Conceptual Approach. Molecules 2020; 25:molecules25081784. [PMID: 32295037 PMCID: PMC7221885 DOI: 10.3390/molecules25081784] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 04/08/2020] [Accepted: 04/11/2020] [Indexed: 11/16/2022] Open
Abstract
Carnitine palmitoyltransferase (CPT) catalyzes the transfer of long- and medium-chain fatty acids from cytoplasm into mitochondria, where oxidation of fatty acids takes place. Deficiency of CPT enzyme is associated with rare diseases of fatty acid metabolism. CPT is present in two subforms: CPT I at the outer mitochondrial membrane and carnitine palmitoyltransferase II (CPT II) inside the mitochondria. Deficiency of CPT II results in the most common inherited disorder of long-chain fatty acid oxidation affecting skeletal muscle. There is a lethal neonatal form, a severe infantile hepato-cardio-muscular form, and a rather mild myopathic form characterized by exercise-induced myalgia, weakness, and myoglobinuria. Total CPT activity (CPT I + CPT II) in muscles of CPT II-deficient patients is generally normal. Nevertheless, in some patients, not detectable to reduced total activities are also reported. CPT II protein is also shown in normal concentration in patients with normal CPT enzymatic activity. However, residual CPT II shows abnormal inhibition sensitivity towards malonyl-CoA, Triton X-100 and fatty acid metabolites in patients. Genetic studies have identified a common p.Ser113Leu mutation in the muscle form along with around 100 different rare mutations. The biochemical consequences of these mutations have been controversial. Hypotheses include lack of enzymatically active protein, partial enzyme deficiency and abnormally regulated enzyme. The recombinant enzyme experiments that we recently conducted have shown that CPT II enzyme is extremely thermoliable and is abnormally inhibited by different emulsifiers and detergents such as malonyl-CoA, palmitoyl-CoA, palmitoylcarnitine, Tween 20 and Triton X-100. Here, we present a conceptual overview on CPT II deficiency based on our own findings and on results from other studies addressing clinical, biochemical, histological, immunohistological and genetic aspects, as well as recent advancements in diagnosis and therapeutic strategies in this disorder.
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Ivin N, Della Torre V, Sanders F, Youngman M. Rhabdomyolysis caused by carnitine palmitoyltransferase 2 deficiency: A case report and systematic review of the literature. J Intensive Care Soc 2019; 21:165-173. [PMID: 32489413 DOI: 10.1177/1751143719889766] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Carnitine palmitoyltransferase 2 deficiency is an inherited metabolic disorder involving a deficiency in a mitochondrial enzyme necessary for long chain fatty acid oxidation, and therefore decreased utilisation of fatty acids. The adult form of this condition leads to recurrent rhabdomyolysis triggered by exercise, fasting and infection. It is a very rare condition with only a few hundred reported cases worldwide. Here we present a case of severe rhabdomyolysis in the context of carnitine palmitoyltransferase 2 deficiency in which major organ involvement was avoided, and organ support was not needed. This prompted us to perform a systematic review of the existing case reports in the literature to ascertain the most frequent patterns of organ involvement and assess the outcomes that are seen in these patients. Our findings suggest that these patients most frequently develop isolated renal failure, often requiring renal replacement therapy; however, the outcomes following this are very good, supporting the early involvement of intensive care teams.
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Affiliation(s)
- Nicholas Ivin
- Critical Care Unit, West Suffolk Hospital, NHS Foundation Trust, Bury St Edmunds, UK
| | - Valentina Della Torre
- Department of Critical Care, Imperial College Healthcare NHS Trust, St Mary's Hospital, London, UK
| | - Francis Sanders
- Critical Care Unit, West Suffolk Hospital, NHS Foundation Trust, Bury St Edmunds, UK
| | - Matthew Youngman
- Critical Care Unit, West Suffolk Hospital, NHS Foundation Trust, Bury St Edmunds, UK
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Carnitine palmitoyltransferase II deficiency with a focus on newborn screening. J Hum Genet 2018; 64:87-98. [PMID: 30514913 DOI: 10.1038/s10038-018-0530-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 10/23/2018] [Accepted: 10/25/2018] [Indexed: 11/08/2022]
Abstract
Carnitine palmitoyltransferase (CPT) II deficiency is one of the most common forms of mitochondrial fatty acid oxidation disorder. Its clinical phenotypes are classified into the muscle, severe infantile, and lethal neonatal forms. Among Caucasians, the muscle form predominates, and the c.338C > T (p.S113L) variant is detected in most cases, whereas among the Japanese, c.1148T > A (p.F383Y) is the variant allele occurring with the highest frequency and can apparently cause symptoms of the severe infantile form. Newborn screening (NBS) for this potentially fatal disease has not been established. We encountered an infantile case of CPT II deficiency not detected in NBS using C16 and C18:1 concentrations as indices, and therefore we adopted the (C16 + C18:1)/C2 ratio as an alternative primary index. As a result, the disease was diagnosed in nine of 31 NBS-positive subjects. The values for (C16 + C18:1)/C2 in the affected newborns partly overlapped with those in unaffected ones. Among several other indices proposed previously, C14/C3 has emerged as a more promising index. Based on these findings, nationwide NBS for CPT II deficiency using both (C16 + C18:1)/C2 and C14/C3 as indices was officially approved and started in April 2018. We diagnosed the disease in four young children presenting with symptoms of the muscle form, whose values for the new indices were not elevated. Although it is still difficult to detect all cases of the muscle form of CPT II deficiency in NBS, our system is expected to save many affected children in Japan with the severe infantile form predominating.
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Tajima G, Hara K, Tsumura M, Kagawa R, Okada S, Sakura N, Maruyama S, Noguchi A, Awaya T, Ishige M, Ishige N, Musha I, Ajihara S, Ohtake A, Naito E, Hamada Y, Kono T, Asada T, Sasai H, Fukao T, Fujiki R, Ohara O, Bo R, Yamada K, Kobayashi H, Hasegawa Y, Yamaguchi S, Takayanagi M, Hata I, Shigematsu Y, Kobayashi M. Newborn screening for carnitine palmitoyltransferase II deficiency using (C16+C18:1)/C2: Evaluation of additional indices for adequate sensitivity and lower false-positivity. Mol Genet Metab 2017; 122:67-75. [PMID: 28801073 DOI: 10.1016/j.ymgme.2017.07.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 07/27/2017] [Accepted: 07/28/2017] [Indexed: 11/21/2022]
Abstract
BACKGROUND Carnitine palmitoyltransferase (CPT) II deficiency is one of the most common forms of mitochondrial fatty acid oxidation disorder (FAOD). However, newborn screening (NBS) for this potentially fatal disease has not been established partly because reliable indices are not available. METHODS We diagnosed CPT II deficiency in a 7-month-old boy presenting with hypoglycemic encephalopathy, which apparently had been missed in the NBS using C16 and C18:1 concentrations as indices. By referring to his acylcarnitine profile from the NBS, we adopted the (C16+C18:1)/C2 ratio (cutoff 0.62) and C16 concentration (cutoff 3.0nmol/mL) as alternative indices for CPT II deficiency such that an analysis of a dried blood specimen collected at postnatal day five retroactively yielded the correct diagnosis. Thereafter, positive cases were assessed by measuring (1) the fatty acid oxidation ability of intact lymphocytes and/or (2) CPT II activity in the lysates of lymphocytes. The diagnoses were then further confirmed by genetic analysis. RESULTS The disease was diagnosed in seven of 21 newborns suspected of having CPT II deficiency based on NBS. We also analyzed the false-negative patient and five symptomatic patients for comparison. Values for the NBS indices of the false-negative, symptomatic patient were lower than those of the seven affected newborns. Although it was difficult to differentiate the false-negative patient from heterozygous carriers and false-positive subjects, the fatty acid oxidation ability of the lymphocytes and CPT II activity clearly confirmed the diagnosis. Among several other indices proposed previously, C14/C3 completely differentiated the seven NBS-positive patients and the false-negative patient from the heterozygous carriers and the false-positive subjects. Genetic analysis revealed 16 kinds of variant alleles. The most prevalent, detected in ten alleles in nine patients from eight families, was c.1148T>A (p.F383Y), a finding in line with those of several previous reports on Japanese patients. CONCLUSIONS These findings suggested that CPT II deficiency can be screened by using (C16+C18:1)/C2 and C16 as indices. An appropriate cutoff level is required to achieve adequate sensitivity albeit at the cost of a considerable increase in the false-positive rate, which might be reduced by using additional indices such as C14/C3.
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Affiliation(s)
- Go Tajima
- Department of Pediatrics, Hiroshima University Graduate School of Biomedical & Health Sciences, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan; Division of Neonatal Screening, Research Institute, National Center for Child Health and Development, 2-10-1 Okura, Setagaya-ku, Tokyo 157-8535, Japan.
| | - Keiichi Hara
- Department of Pediatrics, Hiroshima University Graduate School of Biomedical & Health Sciences, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan; Department of Pediatrics, National Hospital Organization Kure Medical Center and Chugoku Cancer Center, 3-1 Aoyama-cho, Kure 737-0023, Japan.
| | - Miyuki Tsumura
- Department of Pediatrics, Hiroshima University Graduate School of Biomedical & Health Sciences, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan.
| | - Reiko Kagawa
- Department of Pediatrics, Hiroshima University Graduate School of Biomedical & Health Sciences, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan.
| | - Satoshi Okada
- Department of Pediatrics, Hiroshima University Graduate School of Biomedical & Health Sciences, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan.
| | - Nobuo Sakura
- Nursing House for Severe Motor and Intellectual Severities Suzugamine, 104-27 Minaga, Itsukaichi-cho, Saeki-ku, Hiroshima 731-5122, Japan.
| | - Shinsuke Maruyama
- Department of Pediatrics, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8520, Japan.
| | - Atsuko Noguchi
- Department of Pediatrics, Akita University Graduate School of Medicine, 44-2 Hasunuma, Hiroomote, Akita 010-8543, Japan.
| | - Tomonari Awaya
- Department of Pediatrics, Kyoto University Hospital, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan.
| | - Mika Ishige
- Department of Pediatrics and Child Health, Nihon University School of Medicine, 1-6 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8309, Japan.
| | - Nobuyuki Ishige
- Division of Newborn Screening, Tokyo Health Service Association, 1-2-59 Ichiga-Sadohara, Shinjuku-ku, Tokyo 162-8460, Japan.
| | - Ikuma Musha
- Department of Pediatrics, Faculty of Medicine, Saitama Medical University, 38 Morohongo, Moroyama-cho, Saitama 350-0495, Japan.
| | - Sayaka Ajihara
- Department of Pediatrics, Faculty of Medicine, Saitama Medical University, 38 Morohongo, Moroyama-cho, Saitama 350-0495, Japan.
| | - Akira Ohtake
- Department of Pediatrics, Faculty of Medicine, Saitama Medical University, 38 Morohongo, Moroyama-cho, Saitama 350-0495, Japan.
| | - Etsuo Naito
- Department of Pediatrics, Japanese Red Cross Tokushima Hinomine Rehabilitation Center, 4-1 Shinbiraki, Chuden-cho, Komatsushima, Tokushima 773-0015, Japan.
| | - Yusuke Hamada
- Department of Pediatrics, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka 565-0871, Japan.
| | - Tomotaka Kono
- Division of Endocrinology and Metabolism, Saitama Children's Medical Center, 1-2 Shintoshin, Chuo-ku, Saitama 330-8777, Japan.
| | - Tomoko Asada
- Department of Pediatrics, Faculty of Medicine, University of Miyazaki Hospital, 5200 Kihara, Kiyotake-cho, Miyazaki 889-1692, Japan.
| | - Hideo Sasai
- Department of Pediatrics, Graduate School of Medicine, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan.
| | - Toshiyuki Fukao
- Department of Pediatrics, Graduate School of Medicine, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan.
| | - Ryoji Fujiki
- Department of Technology Development, Kazusa DNA Research Institute, Kisarazu, Chiba 292-0818, Japan.
| | - Osamu Ohara
- Department of Technology Development, Kazusa DNA Research Institute, Kisarazu, Chiba 292-0818, Japan.
| | - Ryosuke Bo
- Department of Pediatrics, Shimane University Faculty of Medicine, 89-1 En-ya-cho, Izumo 693-8501, Japan; Department of Pediatrics, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.
| | - Kenji Yamada
- Department of Pediatrics, Shimane University Faculty of Medicine, 89-1 En-ya-cho, Izumo 693-8501, Japan.
| | - Hironori Kobayashi
- Department of Pediatrics, Shimane University Faculty of Medicine, 89-1 En-ya-cho, Izumo 693-8501, Japan.
| | - Yuki Hasegawa
- Department of Pediatrics, Shimane University Faculty of Medicine, 89-1 En-ya-cho, Izumo 693-8501, Japan.
| | - Seiji Yamaguchi
- Department of Pediatrics, Shimane University Faculty of Medicine, 89-1 En-ya-cho, Izumo 693-8501, Japan.
| | - Masaki Takayanagi
- Department of Nursing, Faculty of Health Care and Medical Sport, Teikyo Heisei University, 6-19 Chiharadai-Nishi, Ichihara 290-0192, Japan.
| | - Ikue Hata
- Department of Pediatrics, Faculty of Medical Sciences, University of Fukui, 23-3 Matsuoka-Shimoaizuki, Eiheiji-cho, Fukui 910-1193, Japan.
| | - Yosuke Shigematsu
- Department of Pediatrics, Faculty of Medical Sciences, University of Fukui, 23-3 Matsuoka-Shimoaizuki, Eiheiji-cho, Fukui 910-1193, Japan.
| | - Masao Kobayashi
- Department of Pediatrics, Hiroshima University Graduate School of Biomedical & Health Sciences, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan.
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10
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Postmortem genetic analysis of sudden unexpected death in infancy: neonatal genetic screening may enable the prevention of sudden infant death. J Hum Genet 2017; 62:989-995. [DOI: 10.1038/jhg.2017.79] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 06/27/2017] [Accepted: 06/27/2017] [Indexed: 11/08/2022]
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11
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Yamada K, Bo R, Kobayashi H, Hasegawa Y, Ago M, Fukuda S, Yamaguchi S, Taketani T. A newborn case with carnitine palmitoyltransferase II deficiency initially judged as unaffected by acylcarnitine analysis soon after birth. Mol Genet Metab Rep 2017; 11:59-61. [PMID: 28516040 PMCID: PMC5426073 DOI: 10.1016/j.ymgmr.2017.04.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 04/26/2017] [Accepted: 04/26/2017] [Indexed: 11/27/2022] Open
Abstract
Carnitine palmitoyltransferase II (CPT-2) deficiency, an autosomal recessive disorder of fatty acid oxidation, can be detected by newborn screening using tandem mass spectrometry (TMS). Our case was a boy born at 38 weeks and 6 days of gestation via normal vaginal delivery; his elder sister was affected with CPT-2 deficiency. Acylcarnitine (AC) was analyzed in both dried blood spots (DBS) and serum 2 h after birth to determine whether the boy was also affected. His C16 and C18:1 AC levels in DBS were in the normal range, while his serum long-chain AC levels were marginally increased but lower than those of his sister. After the samples were taken, he was treated with glucose infusion to prevent any catabolism for 2 days. On day 4, the long-chain AC levels in both DBS and serum obtained were higher than those on day 0 and were equivalent to those of his sister. Genetic testing confirmed the presence of the same mutation found in his sister, a homozygous F383Y mutation in the CPT2 gene, thus leading to the diagnosis of CPT-2 deficiency. The sample for TMS should be taken between days 1 and 7. If the sample is not obtained at an appropriate time, correct diagnosis may not be made, as in our case. Although early diagnosis is required, samples taken within 24 h after birth should not be used for TMS.
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Affiliation(s)
- Kenji Yamada
- Department of Pediatrics, Shimane University Faculty of Medicine, 89-1 En-ya-cho, Izumo, Shimane 693-8501, Japan
| | - Ryosuke Bo
- Department of Pediatrics, Kobe University School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe, Hyogo 650-0017, Japan
| | - Hironori Kobayashi
- Department of Pediatrics, Shimane University Faculty of Medicine, 89-1 En-ya-cho, Izumo, Shimane 693-8501, Japan
| | - Yuki Hasegawa
- Department of Pediatrics, Shimane University Faculty of Medicine, 89-1 En-ya-cho, Izumo, Shimane 693-8501, Japan
| | - Mako Ago
- Department of Pediatrics, Shimane University Faculty of Medicine, 89-1 En-ya-cho, Izumo, Shimane 693-8501, Japan
| | - Seiji Fukuda
- Department of Pediatrics, Shimane University Faculty of Medicine, 89-1 En-ya-cho, Izumo, Shimane 693-8501, Japan
| | - Seiji Yamaguchi
- Department of Pediatrics, Shimane University Faculty of Medicine, 89-1 En-ya-cho, Izumo, Shimane 693-8501, Japan
| | - Takeshi Taketani
- Department of Pediatrics, Shimane University Faculty of Medicine, 89-1 En-ya-cho, Izumo, Shimane 693-8501, Japan
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12
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Shima A, Yasuno T, Yamada K, Yamaguchi M, Kohno R, Yamaguchi S, Kido H, Fukuda H. First Japanese Case of Carnitine Palmitoyltransferase II Deficiency with the Homozygous Point Mutation S113L. Intern Med 2016; 55:2659-61. [PMID: 27629963 DOI: 10.2169/internalmedicine.55.6288] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Carnitine palmitoyltransferase II (CPT II) deficiency is a rare inherited disorder related to recurrent episodes of rhabdomyolysis. The adult myopathic form of CPT II deficiency is relatively benign and difficult to diagnose. The point mutation S113L in CPT2 is very common in Caucasian patients, whereas F383Y is the most common mutation among Japanese patients. We herein present a case of CPT II deficiency in a Japanese patient homozygous for the missense mutation S113L. The patient showed a decreased frequency of rhabdomyolysis recurrence after the administration of a diet containing medium-chain triglyceride oil and supplementation with carnitine and bezafibrate.
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Affiliation(s)
- Atsushi Shima
- Department of Neurology, Saiseikai Noe Hospital, Japan
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13
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Metabolic autopsy with next generation sequencing in sudden unexpected death in infancy: Postmortem diagnosis of fatty acid oxidation disorders. Mol Genet Metab Rep 2015. [PMID: 28649538 PMCID: PMC5471402 DOI: 10.1016/j.ymgmr.2015.09.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The recent introduction of metabolic autopsy in the field of forensic science has made it possible to detect hidden inherited metabolic diseases. Since the next generation sequencing (NGS) has recently become available for use in postmortem examinations, we used NGS to perform metabolic autopsy in 15 sudden unexpected death in infancy cases. Diagnostic results revealed a case of carnitine palmitoyltransferase II deficiency and some cases of fatty acid oxidation-related gene variants. Metabolic autopsy performed with NGS is a useful method, especially when postmortem biochemical testing is not available. This is the first metabolic autopsy performed with next generation sequencing (NGS). We detected one case of CPT II deficiency and three cases of FAOD-related rare variants. Some of them had no specific abnormality except for genetic variants. These cases would be undetected without NGS. We advocate metabolic autopsy performed with NGS.
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14
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Abstract
Rhabdomyolysis is characterized by severe acute muscle injury resulting in muscle pain, weakness, and/or swelling with release of myofiber contents into the bloodstream. Symptoms develop over hours to days after an inciting factor and may be associated with dark pigmentation of the urine. Serum creatine kinase and urine myoglobin levels are markedly elevated. Clinical examination, history, laboratory studies, muscle biopsy, and genetic testing are useful tools for diagnosis of rhabdomyolysis, and they can help differentiate acquired from inherited causes of rhabdomyolysis. Acquired causes include substance abuse, medication or toxic exposures, electrolyte abnormalities, endocrine disturbances, and autoimmune myopathies. Inherited predisposition to rhabdomyolysis can occur with disorders of glycogen metabolism, fatty acid β-oxidation, and mitochondrial oxidative phosphorylation. Less common inherited causes of rhabdomyolysis include structural myopathies, channelopathies, and sickle-cell disease. This review focuses on the differentiation of acquired and inherited causes of rhabdomyolysis and proposes a practical diagnostic algorithm. Muscle Nerve 51: 793-810, 2015.
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Affiliation(s)
- Jessica R Nance
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Andrew L Mammen
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,Muscle Disease Unit, Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Building 50, Room 1146, Bethesda, Maryland, 20892, USA
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15
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Abstract
BACKGROUND Mutations of the CPT II gene cause CPT II deficiency, an inborn metabolic error affecting mitochondrial fatty acid β-oxidation. Associations and mechanisms of CPT II gene with acute encephalitis need to be elucidated. We aimed to investigate the associations of CPT II gene variants and CPT II activity with development of acute encephalitis. METHODS A total of 440 blood-unrelated Chinese children with acute encephalitis and 229 healthy controls were enrolled in this case control study. Sequencing of 5 exons of the CPT II gene was carried out to look for the variants associated with acute encephalitis. CPT II activity and blood adenosine triphosphate concentration were examined during high fever and convalescent phase to confirm the hypothesis. RESULTS Polymorphism of rs2229291 in CPT II gene was significantly associated with an increased risk of acute encephalitis (P = 0.031), where as rs1799821 displayed a decrease risk (P = 0.018). Positive association was found between rs2229291 and patients with fever at onset of seizure and degree of pathogenetic condition (P = 0.018 and P = 0.023), but not for rs1799821. CPT II activity of patients with rs2229291 reduced greatly during high fever compared with the convalescent phase. CONCLUSIONS rs2229291 and rs1799821 variants in CPT II gene might be 1 of the predisposing factors of acute encephalitis.
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16
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Three novel mutations in the carnitine-acylcarnitine translocase (CACT) gene in patients with CACT deficiency and in healthy individuals. J Hum Genet 2013; 58:788-93. [PMID: 24088670 DOI: 10.1038/jhg.2013.103] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Revised: 09/04/2013] [Accepted: 09/06/2013] [Indexed: 11/09/2022]
Abstract
Carnitine-acylcarnitine translocase (CACT) and carnitine palmitoyltransferase II (CPT2) are key enzymes for transporting long-chain fatty acids into mitochondria. Deficiencies of these enzymes, which are clinically characterized by life-threatening non-ketotic hypoglycemia and rhabdomyolysis, cannot be distinguished by acylcarnitine analysis performed using tandem mass spectrometry. We had previously reported the CPT2 genetic structure and its role in CPT2 deficiency. Here, we analyzed the CACT gene in 2 patients diagnosed clinically with CACT deficiency, 18 patients with non-traumatic rhabdomyolysis and 58 healthy individuals, all of whom were confirmed to have normal CPT2 genotypes. To facilitate CACT genotyping, we used heat-denaturing high-performance liquid chromatography (DHPLC), which helped identify five distinct patterns. The abnormal heteroduplex fragments were subjected to CACT-specific DNA sequencing. We found that one patient with CACT deficiency, Case 1, carried c.576G>A and c.199-10t>g mutations, whereas Case 2 was heterozygous for c.106-2a>t and c.576G>A. We also found that one patient with non-traumatic rhabdomyolysis and one healthy individual were heterozygous for c.804delG and the synonymous mutation c.516T>C, respectively. In summary, c.576G>A, c.106-2a>t and c.516T>C are novel CACT gene mutations. Among the five mutations identified, three were responsible for CACT deficiency. We have also demonstrated the successful screening of CACT mutations by DHPLC.
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17
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Kobayashi Y, Ishikawa N, Tsumura M, Fujii Y, Okada S, Shigematsu Y, Kobayashi M. Acute severe encephalopathy related to human herpesvirus-6 infection in a patient with carnitine palmitoyltransferase 2 deficiency carrying thermolabile variants. Brain Dev 2013; 35:449-53. [PMID: 22854105 DOI: 10.1016/j.braindev.2012.06.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2012] [Revised: 05/28/2012] [Accepted: 06/29/2012] [Indexed: 11/27/2022]
Abstract
We describe a male infant with carnitine palmitoyltransferase 2 (CPT2) deficiency who presented with acute encephalopathy related to human herpesvirus-6 (HHV-6) infection. He was hospitalized for pylexia and status epilepticus, diagnosed with acute encephalopathy, and treated with intensive supportive care including mechanical ventilation, support for hypothermia, and control of the intracranial pressure, that caused severe neurological sequelae. HHV-6 was detected in his cerebrospinal fluid, indicating HHV-6 related encephalopathy. In the acute phase, acylcarnitine analysis of blood suggested a defect of long chain fatty acid β-oxidation, and CPT2 deficiency was genetically confirmed. In addition, other gene alterations that have been previously reported as "thermolabile variants" were found. Some patients with the infantile form of CPT2 deficiency present with acute encephalopathy, but others do not develop encephalopathy. The correlation between phenotype and genotype has not been clarified. Our case may contribute to the elucidation of the genetic factor involved in acute encephalopathy in CPT2 deficiency.
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Affiliation(s)
- Yoshiyuki Kobayashi
- Department of Pediatrics, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima, Japan.
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18
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Akamizu T, Sakura N, Shigematsu Y, Tajima G, Ohtake A, Hosoda H, Iwakura H, Ariyasu H, Kangawa K. Analysis of plasma ghrelin in patients with medium-chain acyl-CoA dehydrogenase deficiency and glutaric aciduria type II. Eur J Endocrinol 2012; 166:235-40. [PMID: 22048973 DOI: 10.1530/eje-11-0785] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE Ghrelin requires a fatty acid modification for binding to the GH secretagogue receptor. Acylation of the Ser3 residue of ghrelin is essential for its biological activities. We hypothesized that acyl-CoA is the fatty acid substrate for ghrelin acylation. Because serum octanoyl-CoA levels are altered by fatty acid oxidation disorders, we examined circulating ghrelin levels in affected patients. MATERIALS AND METHODS Blood levels of acyl (A) and des-acyl (D) forms of ghrelin and acylcarnitine of patients with medium-chain acyl-CoA dehydrogenase (MCAD) deficiency and glutaric aciduria type II (GA2) were measured. RESULTS Plasma acyl ghrelin levels and A/D ratios increased in patients with MCAD deficiency or GA2 when compared with normal subjects. Reverse-phase HPLC confirmed that n-octanoylated ghrelin levels were elevated in these patients. CONCLUSION Changing serum medium-chain acylcarnitine levels may affect circulating acyl ghrelin levels, suggesting that acyl-CoA is the substrate for ghrelin acylation.
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Affiliation(s)
- Takashi Akamizu
- The First Department of Medicine, Wakayama Medical University, 811-1 Kimi-idera, Wakayama 641-8509, Japan.
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Saini-Chohan HK, Mitchell RW, Vaz FM, Zelinski T, Hatch GM. Delineating the role of alterations in lipid metabolism to the pathogenesis of inherited skeletal and cardiac muscle disorders: Thematic Review Series: Genetics of Human Lipid Diseases. J Lipid Res 2011; 53:4-27. [PMID: 22065858 DOI: 10.1194/jlr.r012120] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
As the specific composition of lipids is essential for the maintenance of membrane integrity, enzyme function, ion channels, and membrane receptors, an alteration in lipid composition or metabolism may be one of the crucial changes occurring during skeletal and cardiac myopathies. Although the inheritance (autosomal dominant, autosomal recessive, and X-linked traits) and underlying/defining mutations causing these myopathies are known, the contribution of lipid homeostasis in the progression of these diseases needs to be established. The purpose of this review is to present the current knowledge relating to lipid changes in inherited skeletal muscle disorders, such as Duchenne/Becker muscular dystrophy, myotonic muscular dystrophy, limb-girdle myopathic dystrophies, desminopathies, rostrocaudal muscular dystrophy, and Dunnigan-type familial lipodystrophy. The lipid modifications in familial hypertrophic and dilated cardiomyopathies, as well as Barth syndrome and several other cardiac disorders associated with abnormal lipid storage, are discussed. Information on lipid alterations occurring in these myopathies will aid in the design of improved methods of screening and therapy in children and young adults with or without a family history of genetic diseases.
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Affiliation(s)
- Harjot K Saini-Chohan
- Department of Pharmacology and Therapeutics, Academic Medical Center, Amsterdam, The Netherlands
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20
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Yamamoto T, Tanaka H, Kobayashi H, Okamura K, Tanaka T, Emoto Y, Sugimoto K, Nakatome M, Sakai N, Kuroki H, Yamaguchi S, Matoba R. Retrospective review of Japanese sudden unexpected death in infancy: the importance of metabolic autopsy and expanded newborn screening. Mol Genet Metab 2011; 102:399-406. [PMID: 21227726 DOI: 10.1016/j.ymgme.2010.12.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Accepted: 12/07/2010] [Indexed: 11/29/2022]
Abstract
Sudden unexpected death in infancy is defined as sudden unexpected death occurring before 12 months of age. The common causes of sudden unexpected death in infancy are infection, cardiovascular anomaly, child abuse, and metabolic disorders. However, the many potential inherited metabolic disorders are difficult to diagnose at autopsy and may therefore be underdiagnosed as a cause of sudden unexpected death in infancy. In the present study we retrospectively reviewed 30 Japanese sudden unexpected death in infancy cases encountered between 2006 and 2009 at our institute. With postmortem blood acylcarnitine analysis and histological examination of the liver, we found two cases of long-chain fatty acid oxidation defects. Molecular analysis revealed that the one patient had a compound heterozygote for a novel mutation (p.L644S) and a disease-causing mutation (p.F383Y) in the carnitine palmitoyltransferase 2 gene. Furthermore, retrospective acylcarnitine analysis of the newborn screening card of this patient was consistent with carnitine palmitoyltransferase II deficiency. Metabolic autopsy and expanded newborn screening would be helpful for forensic scientists and pediatricians to diagnose fatty acid oxidation disorders and prevent sudden unexpected death in infancy.
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Affiliation(s)
- Takuma Yamamoto
- Department of Legal Medicine, Osaka University Graduate School of Medicine, 2-2 Yamada-Oka, Suita, Osaka 565-0871, Japan
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21
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Abstract
PURPOSE OF REVIEW The aim of this review is to provide an update on disorders of lipid metabolism affecting skeletal muscle exclusively or predominantly and to summarize recent clinical, genetic, and therapeutic studies in this field. RECENT FINDINGS Over the past 5 years, new clinical phenotypes and genetic loci have been described, unusual pathogenic mechanisms have been elucidated, and novel pharmacological approaches have been developed. At least one genetic defect responsible for the myopathic form of CoQ10 deficiency has been identified, causing a disorder that is allelic with the late-onset riboflavine-responsive form of multiple acyl-coenzyme A dehydrogenation deficiency. Novel mechanisms involved in the lipolytic breakdown of cellular lipid depots have been described and have led to the identification of genes and mutations responsible for multisystemic neutral lipid storage disorders, characterized by accumulation of triglyceride in multiple tissues, including muscle. SUMMARY Defects in lipid metabolism can affect either the mitochondrial transport and oxidation of exogenous fatty acid or the catabolism of endogenous triglycerides. These disorders impair energy production and almost invariably involve skeletal muscle, causing progressive myopathy with muscle weakness, or recurrent acute episodes of rhabdomyolysis triggered by exercise, fasting, or infections. Clinical and genetic characterization of these disorders has important implications both for accurate diagnostic approach and for development of therapeutic strategies.
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