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Doshi HP, Vachharajani HH, Tchan MC, Nasreddine MA, Billmore KE. Metabolic crisis in maple syrup urine disease: an unusual complication of a rare disease: a case report. Anaesth Intensive Care 2024; 52:64-68. [PMID: 37994838 DOI: 10.1177/0310057x231183981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2023]
Abstract
A 19-year-old woman with known maple syrup urine disease presented to hospital with metabolic crisis in the setting of influenza type A infection and intractable vomiting, rapidly progressing to acute cerebral oedema manifesting as refractory seizures and decreased level of consciousness needing emergency intubation and mechanical ventilation, continuous veno-venous haemodiafiltration and thiopentone coma. A computed tomography scan and magnetic resonance imaging of the brain demonstrated classic signs of cerebral oedema secondary to a metabolic crisis from the metabolic disorder. Her management posed multiple challenges to all teams involved due to lack of familiarity and experience in managing this clinical scenario in the adult intensive care setting.
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Affiliation(s)
- Hemang P Doshi
- Department of Intensive Care Services, Westmead Hospital, Sydney, Australia
| | | | - Michael C Tchan
- Department of Genetic Medicine, Westmead Hospital, Sydney, Australia
| | | | - Kate E Billmore
- Department of Genetic Medicine, Westmead Hospital, Sydney, Australia
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2
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Pontoizeau C, Gaborit C, Tual N, Simon-Sola M, Rotaru I, Benoist M, Colella P, Lamazière A, Brassier A, Arnoux JB, Rötig A, Ottolenghi C, de Lonlay P, Mingozzi F, Cavazzana M, Schiff M. Successful treatment of severe MSUD in Bckdhb -/- mice with neonatal AAV gene therapy. J Inherit Metab Dis 2024; 47:41-49. [PMID: 36880392 DOI: 10.1002/jimd.12604] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 02/11/2023] [Accepted: 03/02/2023] [Indexed: 03/08/2023]
Abstract
Maple syrup urine disease (MSUD) is rare autosomal recessive metabolic disorder caused by the dysfunction of the mitochondrial branched-chain 2-ketoacid dehydrogenase (BCKD) enzyme complex leading to massive accumulation of branched-chain amino acids and 2-keto acids. MSUD management, based on a life-long strict protein restriction with nontoxic amino acids oral supplementation represents an unmet need as it is associated with a poor quality of life, and does not fully protect from acute life-threatening decompensations or long-term neuropsychiatric complications. Orthotopic liver transplantation is a beneficial therapeutic option, which shows that restoration of only a fraction of whole-body BCKD enzyme activity is therapeutic. MSUD is thus an ideal target for gene therapy. We and others have tested AAV gene therapy in mice for two of the three genes involved in MSUD, BCKDHA and DBT. In this study, we developed a similar approach for the third MSUD gene, BCKDHB. We performed the first characterization of a Bckdhb-/- mouse model, which recapitulates the severe human phenotype of MSUD with early-neonatal symptoms leading to death during the first week of life with massive accumulation of MSUD biomarkers. Based on our previous experience in Bckdha-/- mice, we designed a transgene carrying the human BCKDHB gene under the control of a ubiquitous EF1α promoter, encapsidated in an AAV8 capsid. Injection in neonatal Bckdhb-/- mice at 1014 vg/kg achieved long-term rescue of the severe MSUD phenotype of Bckdhb-/- mice. These data further validate the efficacy of gene therapy for MSUD opening perspectives towards clinical translation.
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Affiliation(s)
- Clément Pontoizeau
- Necker Hospital, APHP, Biochemistry, Metabolomics Unit, University Paris Cité, Paris, France
- Necker Hospital, APHP, Reference Center for Inborn Error of Metabolism, Pediatrics Department, University Paris Cité, Paris, France
- Inserm UMR_S1163, Institut Imagine, Paris, France
| | | | - Nolan Tual
- Inserm UMR_S1163, Institut Imagine, Paris, France
| | | | - Irina Rotaru
- Inserm UMR_S1163, Institut Imagine, Paris, France
| | | | | | | | - Anaïs Brassier
- Necker Hospital, APHP, Reference Center for Inborn Error of Metabolism, Pediatrics Department, University Paris Cité, Paris, France
| | - Jean-Baptiste Arnoux
- Necker Hospital, APHP, Reference Center for Inborn Error of Metabolism, Pediatrics Department, University Paris Cité, Paris, France
| | - Agnès Rötig
- Inserm UMR_S1163, Institut Imagine, Paris, France
| | - Chris Ottolenghi
- Necker Hospital, APHP, Biochemistry, Metabolomics Unit, University Paris Cité, Paris, France
- Necker Hospital, APHP, Reference Center for Inborn Error of Metabolism, Pediatrics Department, University Paris Cité, Paris, France
- Inserm UMR_S1163, Institut Imagine, Paris, France
| | - Pascale de Lonlay
- Necker Hospital, APHP, Reference Center for Inborn Error of Metabolism, Pediatrics Department, University Paris Cité, Paris, France
- Inserm U1151, Institut Necker Enfants Malades, Paris, France
| | | | - Marina Cavazzana
- Inserm UMR_S1163, Institut Imagine, Paris, France
- Necker Hospital, APHP, Biotherapies Department and Clinical Investigation Center, Inserm, University Paris Cité, Paris, France
| | - Manuel Schiff
- Necker Hospital, APHP, Reference Center for Inborn Error of Metabolism, Pediatrics Department, University Paris Cité, Paris, France
- Inserm UMR_S1163, Institut Imagine, Paris, France
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3
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Nasrallah F, Hadj-Taieb S, Sanhaji H, Kaabachi N, Feki M. Analysis of Branched Amino Acids by UPLC as an Alternative Method for the Management of Patients with MUSD. Clin Lab 2023; 69. [PMID: 38084699 DOI: 10.7754/clin.lab.2023.230613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
BACKGROUND Maple syrup urine disease (MSUD) is a severe life-threatening metabolic disorder. Patients' poor outcomes could be prevented by early diagnosis and regular monitoring, which mainly depend on the analysis of branched amino acids (BCAAs) in plasma. The study aimed to test whether the analysis of BCAAs by ultra-performance liquid chromatography (UPLC) is an alternative to an analysis by ion-exchange chromatography (IEC) for the diagnosis and monitoring of MSUD. METHODS The two methods analyzed fifty plasma samples obtained from treated and untreated patients with MSUD. Data were analyzed using Passing-Bablok and Bland-Altman methods. RESULTS The slope of the regression lines was equal or close to one for the three BCAAs, indicating no significant proportional differences between the two methods. A slight positive or negative bias was found for leucine and alloisoleucine, respectively. However, for each amino acid, one or two measurement pairs were out of statistical interval of agreement. Despite small analytical differences, the two methods could be considered in clinical agreement since the differences have no impact on the diagnosis and management of patients. CONCLUSIONS UPLC and IEC methods are in clinical agreement for plasma BCAAs analysis. The UPLC method could be used simultaneously or interchangeably with the IEC method for diagnosing and monitoring MSUD patients. However, for reasons of practicability, the alternative method should only be used when the usual method cannot be carried out.
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Al Shidhani A, Al Hinai A, Al Thihli K, Al Mandhari H, Al Yaarubi S, Ullah I, Al-Hashmi N, Al Murshedi F. Congenital Hyperinsulinism and Maple Syrup Urine Disease: A Challenging Combination. J Clin Res Pediatr Endocrinol 2023; 15:302-306. [PMID: 34738771 PMCID: PMC10448551 DOI: 10.4274/jcrpe.galenos.2021.2021.0173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 09/28/2021] [Indexed: 12/01/2022] Open
Abstract
Congenital hyperinsulinism (CHI) is the most common cause of persistent hypoglycemia in infancy. CHI is a challenging disease to diagnose and manage. Moreover, complicating the course of the disease with another metabolic disease, in this case maple syrup urine disease (MSUD), adds more challenges to the already complex management. We report a term neonate who developed symptomatic, non-ketotic hypoglycemia with a blood glucose (BG) level of 1.9 mmol/L at 21-hours of life. A critical sample at that time showed high serum insulin and C-peptide levels confirming the diagnosis of CHI. Tandem mass spectrometry done at the same time was suggestive of MSUD which was confirmed by high performance liquid chromatography. The diagnosis of both conditions was subsequently confirmed by molecular genetic testing. His hypoglycemia was managed with high glucose infusion with medical therapy for CHI and branched chain amino acids (BCAA) restricted medical formula. At the age of four months, a near-total pancreatectomy was done, due to the failure of conventional therapy. Throughout his complicated course, he required meticulous monitoring of his BG and modified plasma amino acid profile aiming to maintain the BG at ≥3.9 mmol/L and levels of the three BCAAs at the disease therapeutic targets for his age. The patient is currently 29 months old and has normal growth and development. This patient is perhaps the only known case of the co-occurrence of CHI with MSUD. Both hypoglycemia and leucine encephalopathy can result in death or permanent neurological damage. The management of CHI and MSUD in combination is very challenging.
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Affiliation(s)
- Azza Al Shidhani
- Sultan Qaboos University Hospital, Department of Child Health, Muscat, Oman
| | | | - Khalid Al Thihli
- Sultan Qaboos University Hospital, Department of Genetics, Muscat, Oman
| | - Hilal Al Mandhari
- Sultan Qaboos University Hospital, Department of Child Health, Muscat, Oman
| | - Saif Al Yaarubi
- Sultan Qaboos University Hospital, Department of Child Health, Muscat, Oman
| | - Irfan Ullah
- Sultan Qaboos University Hospital, Department of Child Health, Muscat, Oman
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Chen T, Lu D, Xu F, Ji W, Zhan X, Gao X, Qiu W, Zhang H, Liang L, Gu X, Han L. Newborn screening of maple syrup urine disease and the effect of early diagnosis. Clin Chim Acta 2023; 548:117483. [PMID: 37421976 DOI: 10.1016/j.cca.2023.117483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 07/03/2023] [Accepted: 07/05/2023] [Indexed: 07/10/2023]
Abstract
BACKGROUND Maple syrup urine disease (MSUD) is a rare disease for which newborn screening (NBS) is feasible but not universally applied in China. We shared our experiences with MSUD NBS. METHODS Tandem mass spectrometry-based NBS for MSUD was implemented in January 2003, and diagnostic methods included urine organic acid analysis via gas chromatography-mass spectrometry and genetic analysis. RESULTS Six MSUD patients were identified from 1.3 million newborns, yielding an incidence of 1:219,472, in Shanghai, China. The areas under the curve (AUCs) of total leucine (Xle), Xle/phenylalanine ratio, and Xle/alanine ratio were all 1.000. Some amino acid and acylcarnitine concentrations were markedly low in MSUD patients. 47 MSUD patients identified here and in other centers were investigated, which included 14 patients identified by NBS and 33 patients diagnosed clinically. Forty-four patients were subclassified into classic (n = 29), intermediate (n = 11) and intermittent (n = 4) subtypes. Due to earlier diagnosis and treatment, screened classic patients showed a higher survival rate (62.5%, 5/8) than clinically diagnosed classic patients (5.2%, 1/19). Overall, 56.8% (25/44) of MSUD patients and 77.8% (21/27) of classic patients carried variants in the BCKDHB gene. Among 61 identified genetic variants, 16 novel variants were identified. CONCLUSION MSUD NBS in Shanghai, China, enabled earlier detection and increased survivorship in the screened population.
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Affiliation(s)
- Ting Chen
- Department of Pediatric Endocrinology and Genetic Metabolism, Shanghai Institute for Pediatric Research, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200092, China
| | - Deyun Lu
- Department of Pediatric Endocrinology and Genetic Metabolism, Shanghai Institute for Pediatric Research, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200092, China
| | - Feng Xu
- Department of Pediatric Endocrinology and Genetic Metabolism, Shanghai Institute for Pediatric Research, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200092, China
| | - Wenjun Ji
- Department of Pediatric Endocrinology and Genetic Metabolism, Shanghai Institute for Pediatric Research, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200092, China
| | - Xia Zhan
- Department of Pediatric Endocrinology and Genetic Metabolism, Shanghai Institute for Pediatric Research, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200092, China
| | - Xiaolan Gao
- Department of Pediatric Endocrinology and Genetic Metabolism, Shanghai Institute for Pediatric Research, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200092, China
| | - Wenjuan Qiu
- Department of Pediatric Endocrinology and Genetic Metabolism, Shanghai Institute for Pediatric Research, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200092, China
| | - Huiwen Zhang
- Department of Pediatric Endocrinology and Genetic Metabolism, Shanghai Institute for Pediatric Research, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200092, China
| | - Lili Liang
- Department of Pediatric Endocrinology and Genetic Metabolism, Shanghai Institute for Pediatric Research, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200092, China
| | - Xuefan Gu
- Department of Pediatric Endocrinology and Genetic Metabolism, Shanghai Institute for Pediatric Research, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200092, China
| | - Lianshu Han
- Department of Pediatric Endocrinology and Genetic Metabolism, Shanghai Institute for Pediatric Research, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200092, China.
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Ozcelik F, Arslan S, Ozguc Caliskan B, Kardas F, Ozkul Y, Dundar M. PPM1K defects cause mild maple syrup urine disease: The second case in the literature. Am J Med Genet A 2023; 191:1360-1365. [PMID: 36706222 DOI: 10.1002/ajmg.a.63129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Revised: 01/11/2023] [Accepted: 01/13/2023] [Indexed: 01/29/2023]
Abstract
Maple syrup urine disease (MSUD) is an inborn error of metabolism caused by the insufficient catabolism of branched-chain amino acids. BCKDHA, BCKDHB, DBT, and DLD encode the subunits of the branched-chain α-ketoacid dehydrogenase complex, which is responsible for the catabolism of these amino acids. Biallelic pathogenic variants in BCKDHA, BCKDHB, or DBT are characteristic of MSUD. In addition, a patient with a PPM1K defect was previously reported. PPM1K dephosphorylates and activates the enzyme complex. We report a patient with MSUD with mild findings and elevated BCAA levels carrying a novel homozygous start-loss variant in PPM1K. Our study offers further evidence that PPM1K variants cause mild MSUD.
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Affiliation(s)
- Firat Ozcelik
- Department of Medical Genetics, Erciyes University, Kayseri, Turkey
| | - Sezai Arslan
- Division of Nutrition and Metabolism, Department of Pediatrics, Erciyes University, Kayseri, Turkey
| | | | - Fatih Kardas
- Division of Nutrition and Metabolism, Department of Pediatrics, Erciyes University, Kayseri, Turkey
| | - Yusuf Ozkul
- Department of Medical Genetics, Erciyes University, Kayseri, Turkey
| | - Munis Dundar
- Department of Medical Genetics, Erciyes University, Kayseri, Turkey
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Liu Q, Li F, Zhou J, Liu X, Peng J, Gong L. Neonatal maple syrup urine disease case report and literature review. Medicine (Baltimore) 2022; 101:e32174. [PMID: 36550798 PMCID: PMC9771221 DOI: 10.1097/md.0000000000032174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
RATIONALE The main clinical symptoms of maple syrup urine disease (MSUD) are dehydration, acidosis, nervous system symptoms and intellectual disability. The brain imaging findings were mainly caused by cytotoxic edema. The lesions usually occur at the site consistent with the myelination process of normal neonates. The distribution is mostly symmetric, and the diffusion is obviously limited. PATIENT CONCERNS Herein, we report a rare case of an 8-day-old female patient who presented with abnormal symptoms, such as difficulty eating, convulsions, slow reaction, difficulty in correcting hypoglycemia and severe metabolic disorders. Brain magnetic resonance imaging (MRI) revealed abnormal signal intensity mainly involving the brainstem, cervical spinal cord, bilateral cerebellar hemispheres, basal ganglia, thalamus, precentral gyrus, and postcentral gyrus with characteristic hyperintensity on diffusion-weighted imaging (DWI) sequence. MSUD is rarely reported, while cervical spinal cord involvement is extremely rare. DIAGNOSES Blood tandem mass spectrometry, urine organic acid detection, and genetic disease overall genetic tests were performed to further confirm the diagnosis of MSUD. INTERVENTIONS Under general anesthesia, she underwent open surgical procedures for liver transplantation. OUTCOMES The child was in a stable condition after liver transplantation, and the diet was not restricted. LESSONS MSUD in neonates is rare. Our case report and literature review was aim to describe the clinic and imaging characteristics of it, and highlight physicians must be aware of this entity in newborns so as to reduce misdiagnosis due to unfamiliarity.
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Affiliation(s)
- Qiao Liu
- Department of Medical Imaging Center, Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Fang Li
- Department of Medical Imaging Center, Ganzhou People’s Hospital, Ganzhou, China
| | - Jingjing Zhou
- Department of Medical Imaging Center, Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Xiaoyu Liu
- Department of Medical Imaging Center, Ganzhou People’s Hospital, Ganzhou, China
| | - Jidong Peng
- Department of Medical Imaging Center, Ganzhou People’s Hospital, Ganzhou, China
| | - Lianggeng Gong
- Department of Medical Imaging Center, Second Affiliated Hospital of Nanchang University, Nanchang, China
- * Correspondence: Lianggeng Gong, Department of Medical Imaging Center, Second Affiliated Hospital of Nanchang University, Nanchang, China (e-mail: )
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8
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Zhang C, Feng X, Yao L, Hao S, Hui L, Chen X, Zheng L, Wang X, Zhang Q, Cao Z. [Genetic analysis of two Chinese families with maple syrup urine disease]. Zhonghua Yi Xue Yi Chuan Xue Za Zhi 2022; 39:689-693. [PMID: 35810422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
OBJECTIVE To carry out genetic analysis for 3 children from two Chinese families affected with maple syrup urine disease (MSUD). METHODS Target capture - next-generation sequencing and Sanger sequencing were used to detect pathogenic variants associated with MSUD. RESULTS The proband from family 1 was found to harbor homozygous c.560G>T (p.Gly187Val) variant of the BCKDHB gene (NM_000056), whilst the two patients from family 2 were found to harbor compound heterozygous variants c.197-2A>G (splicing)/c.218delT (p.F74Sfs*4) of the BCKDHB gene. Among these, the c.560G>T and c.218delT variants were unreported previously. CONCLUSION The new variants discovered in this study have expanded the mutational spectrum of the BCKDHB gene.
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Affiliation(s)
- Chuan Zhang
- 1National Research Institute for Health and Family Planning, National Human Genetic Resources Center, Beijing 100081, China.
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Fang X, Zhu X, Feng Y, Bai Y, Zhao X, Liu N, Kong X. Genetic analysis by targeted next-generation sequencing and novel variation identification of maple syrup urine disease in Chinese Han population. Sci Rep 2021; 11:18939. [PMID: 34556729 PMCID: PMC8460745 DOI: 10.1038/s41598-021-98357-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 09/07/2021] [Indexed: 11/25/2022] Open
Abstract
Maple syrup urine disease (MSUD) is a rare autosomal recessive disorder that affects the degradation of branched chain amino acids (BCAAs). Only a few cases of MSUD have been documented in Mainland China. In this report, 8 patients (4 females and 4 males) with MSUD from 8 unrelated Chinese Han families were diagnosed at the age of 6 days to 4 months. All the coding regions and exon/intron boundaries of BCKDHA, BCDKHB, DBT and DLD genes were analyzed by targeted NGS in the 8 MSUD pedigrees. Targeted NGS revealed 2 pedigrees with MSUD Ia, 5 pedigrees with Ib, 1 pedigree with MSUD II. Totally, 13 variants were detected, including 2 variants (p.Ala216Val and p.Gly281Arg) in BCKDHA gene, 10 variants (p.Gly95Ala, p.Ser171Pro, p.Phe175Leu, p.Arg183Trp, p.Lys222Thr, p.Arg285Ter, p.Arg111Ter, p.S184Pfs*46, p.Arg170Cys, p.I160Ffs*25) in BCKDHB gene, 1 variant (p.Arg431Ter) in DBT gene. In addition, 4 previously unidentified variants (p.Gly281Arg in BCKDHA gene, p.Ser171Pro, p.Gly95Ala and p.Lys222Thr in BCKDHB gene) were identified. NGS plus Sanger sequencing detection is effective and accurate for gene diagnosis. Computational structural modeling indicated that these novel variations probably affect structural stability and considered as likely pathogenic variants.
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Affiliation(s)
- Xiaohua Fang
- Obstetrics and Gynecology Department, Genetics and Prenatal Diagnosis Center, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, People's Republic of China
| | - Xiaofan Zhu
- Obstetrics and Gynecology Department, Genetics and Prenatal Diagnosis Center, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, People's Republic of China
| | - Yin Feng
- Obstetrics and Gynecology Department, Genetics and Prenatal Diagnosis Center, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, People's Republic of China
| | - Ying Bai
- Obstetrics and Gynecology Department, Genetics and Prenatal Diagnosis Center, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, People's Republic of China
| | - Xuechao Zhao
- Obstetrics and Gynecology Department, Genetics and Prenatal Diagnosis Center, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, People's Republic of China
| | - Ning Liu
- Obstetrics and Gynecology Department, Genetics and Prenatal Diagnosis Center, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, People's Republic of China.
| | - Xiangdong Kong
- Obstetrics and Gynecology Department, Genetics and Prenatal Diagnosis Center, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, People's Republic of China.
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O'Reilly D, Crushell E, Hughes J, Ryan S, Rogers Y, Borovickova I, Mayne P, Riordan M, Awan A, Carson K, Hunter K, Lynch B, Shahwan A, Rüfenacht V, Häberle J, Treacy EP, Monavari AA, Knerr I. Maple syrup urine disease: Clinical outcomes, metabolic control, and genotypes in a screened population after four decades of newborn bloodspot screening in the Republic of Ireland. J Inherit Metab Dis 2021; 44:639-655. [PMID: 33300147 DOI: 10.1002/jimd.12337] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 11/05/2020] [Accepted: 12/07/2020] [Indexed: 12/27/2022]
Abstract
Since 1972, 18 patients (10 females/8 males) have been detected by newborn bloodspot screening (NBS) with neonatal-onset maple syrup urine disease (MSUD) in Ireland. Patients were stratified into three clusters according to clinical outcome at the time of data collection, including developmental, clinical, and IQ data. A fourth cluster comprised of two early childhood deaths; a third patient died as an adult. We present neuroimaging and electroencephalography together with clinical and biochemical data. Incidence of MSUD (1972-2018) was 1 in 147 975. Overall good clinical outcomes were achieved with 15/18 patients alive and with essentially normal functioning (with only the lowest performing cluster lying beyond a single SD on their full scale intelligence quotient). Molecular genetic analysis revealed genotypes hitherto not reported, including a possible digenic inheritance state for the BCKDHA and DBT genes in one family. Treatment has been based on early implementation of emergency treatment, diet, close monitoring, and even dialysis in the setting of acute metabolic decompensation. A plasma leucine ≥400 μmol/L (outside therapeutic range) was more frequently observed in infancy or during adolescence, possibly due to infections, hormonal changes, or noncompliance. Children require careful management during metabolic decompensations in early childhood, and this represented a key risk period in our cohort. A high level of metabolic control can be achieved through diet with early implementation of a "sick day" regime and, in some cases, dialysis as a rescue therapy. The Irish cohort, despite largely classical phenotypes, achieved good outcomes in the NBS era, underlining the importance of early diagnosis and skilled multidisciplinary team management.
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Affiliation(s)
- Daniel O'Reilly
- National Centre for Inherited Metabolic Disorders, Children's Health Ireland at Temple Street, Dublin, Ireland
| | - Ellen Crushell
- National Centre for Inherited Metabolic Disorders, Children's Health Ireland at Temple Street, Dublin, Ireland
| | - Joanne Hughes
- National Centre for Inherited Metabolic Disorders, Children's Health Ireland at Temple Street, Dublin, Ireland
| | - Stephanie Ryan
- Department of Paediatric Radiology, Children's Health Ireland at Temple Street, Dublin, Ireland
| | - Yvonne Rogers
- National Centre for Inherited Metabolic Disorders, Children's Health Ireland at Temple Street, Dublin, Ireland
| | - Ingrid Borovickova
- Metabolic Laboratory, Children's Health Ireland at Temple Street, Dublin, Ireland
- National Newborn Screening Laboratory, Children's Health Ireland at Temple Street, Dublin, Ireland
| | - Philip Mayne
- Metabolic Laboratory, Children's Health Ireland at Temple Street, Dublin, Ireland
- National Newborn Screening Laboratory, Children's Health Ireland at Temple Street, Dublin, Ireland
| | - Michael Riordan
- Department of Nephrology, Children's Health Ireland at Temple Street, Dublin, Ireland
| | - Atif Awan
- Department of Nephrology, Children's Health Ireland at Temple Street, Dublin, Ireland
| | - Kevin Carson
- Paediatric Intensive Care Unit, Children's Health Ireland at Temple Street, Dublin, Ireland
| | - Kim Hunter
- Paediatric Intensive Care Unit, Children's Health Ireland at Temple Street, Dublin, Ireland
| | - Bryan Lynch
- Department of Neurology, Children's Health Ireland at Temple Street, Dublin, Ireland
| | - Amre Shahwan
- Department of Neurology, Children's Health Ireland at Temple Street, Dublin, Ireland
| | - Véronique Rüfenacht
- Division of Metabolism and Children's Research Centre, University Children's Hospital, Zurich, Switzerland
| | - Johannes Häberle
- Division of Metabolism and Children's Research Centre, University Children's Hospital, Zurich, Switzerland
| | - Eileen P Treacy
- Adult Metabolic Services/National Centre for Inherited Metabolic Disorders, Mater Misericordiae University Hospital, Dublin, Ireland
| | - Ahmad A Monavari
- National Centre for Inherited Metabolic Disorders, Children's Health Ireland at Temple Street, Dublin, Ireland
| | - Ina Knerr
- National Centre for Inherited Metabolic Disorders, Children's Health Ireland at Temple Street, Dublin, Ireland
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11
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Sun WH, Wu BB, Wang YQ, Wu MY, Dong XR, Zhang YP, Lu W, Zhang P, Yang B, Zhang M, Wu HJ, Zhou WH. Identification of eight novel mutations in 11 Chinese patients with maple syrup urine disease. World J Pediatr 2020; 16:401-410. [PMID: 32193832 DOI: 10.1007/s12519-020-00349-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 02/18/2020] [Indexed: 12/17/2022]
Abstract
BACKGROUND Maple syrup urine disease (MSUD) is an autosomal recessive inherited disorder that affects the degradation of branched-chain amino acids and is associated with acute and chronic brain dysfunction. This study presents 11 new patients with MSUD and describes the clinical characteristics and gene mutations reported in Chinese individuals. METHODS During 2011-2018, 11 pedaitric patients with MSUD from 11 Chinese families were analyzed based on clinical characteristics and mass spectrometry, with confirmation via gene sequencing. Novel mutations affecting protein function were predicted with Mutation-Taster, PolyPhen-2, CADD and SIFT software. 3D models of the mutated proteins were generated by using the SWISS-MODEL online server, and the models were visualized in PyMOL. The characteristics and gene mutations in patients with MSUD were analyzed retrospectively. RESULTS Seventeen mutations in the BCKDHA, BCKDHB and DBT genes were found, 8 of which are novel: c.55C>/T, c.349C>T, c.565C>T, c.808G>A, c.859C>G, and c.1270dupC in BCKDHA; c.275-2A>G in BCKDHB; and c.1291C>T in DBT. Eight patients died. Two patients had severe mental retardation and were physically handicapped. One patient with the intermediate type had relatively good prognosis, with mild psychomotor retardation and adiposity. Four mothers underwent amniocentesis for prenatal diagnosis during their second pregnancy; two fetuses were wild type, and two were carriers of one heterozygous mutation. CONCLUSIONS Eight novel mutations were associated with MSUD in Chinese patients. Prenatal diagnosis was successfully performed by genetic analysis. Mutations in the BCKDHB gene were found in the majority of Chinese patients with MSUD.
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Affiliation(s)
- Wei-Hua Sun
- Institute of Pediatrics, Shanghai Key Laboratory of Birth Defects, Children's Hospital of Fudan University, Wanyuan Road 399, Shanghai, 201102, China
| | - Bing-Bing Wu
- Institute of Pediatrics, Shanghai Key Laboratory of Birth Defects, Children's Hospital of Fudan University, Wanyuan Road 399, Shanghai, 201102, China
- Key Laboratory of Neonatal Diseases, Ministry of Health, Children's Hospital of Fudan University, Shanghai, 201102, China
| | - Ya-Qiong Wang
- Institute of Pediatrics, Shanghai Key Laboratory of Birth Defects, Children's Hospital of Fudan University, Wanyuan Road 399, Shanghai, 201102, China
| | - Meng-Yuan Wu
- Institute of Pediatrics, Shanghai Key Laboratory of Birth Defects, Children's Hospital of Fudan University, Wanyuan Road 399, Shanghai, 201102, China
| | - Xin-Ran Dong
- Institute of Pediatrics, Shanghai Key Laboratory of Birth Defects, Children's Hospital of Fudan University, Wanyuan Road 399, Shanghai, 201102, China
| | - Yue-Ping Zhang
- Shanghai Ji-ai Genetics and IVF Institute, Obstetrics and Gynecology Hospital, Fudan University, Shanghai, 200011, China
| | - Wei Lu
- Department of Endocrinology, Children's Hospital of Fudan University, Shanghai, 201102, China
| | - Ping Zhang
- Institute of Pediatrics, Shanghai Key Laboratory of Birth Defects, Children's Hospital of Fudan University, Wanyuan Road 399, Shanghai, 201102, China
| | - Bin Yang
- Department of Radiology, Children's Hospital of Shanghai, Shanghai, 201102, China
| | - Min Zhang
- Department of Neurology, Children's Hospital of Fudan University, Shanghai, 201102, China
| | - Hong-Jiang Wu
- Institute of Pediatrics, Shanghai Key Laboratory of Birth Defects, Children's Hospital of Fudan University, Wanyuan Road 399, Shanghai, 201102, China
| | - Wen-Hao Zhou
- Institute of Pediatrics, Shanghai Key Laboratory of Birth Defects, Children's Hospital of Fudan University, Wanyuan Road 399, Shanghai, 201102, China.
- Key Laboratory of Neonatal Diseases, Ministry of Health, Children's Hospital of Fudan University, Shanghai, 201102, China.
- Shanghai Key Laboratory of Birth Defects, The Translational Medicine Center of Children Development and Disease of Fudan University, Children's Hospital of Fudan University, Shanghai, 201102, China.
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Li X, Yang Y, Gao Q, Gao M, Lv Y, Dong R, Liu Y, Zhang K, Gai Z. Clinical characteristics and mutation analysis of five Chinese patients with maple syrup urine disease. Metab Brain Dis 2018; 33:741-751. [PMID: 29307017 DOI: 10.1007/s11011-017-0168-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 12/11/2017] [Indexed: 11/28/2022]
Abstract
Maple syrup urine disease (MSUD) is an autosomal recessive disorder affecting branched-chain amino acids (BCAAs) metabolism and caused by a defect in the thiamine-dependent enzyme branched chain α-ketoacid dehydrogenase (BCKD) with subsequent accumulation of BCAAs and corresponding branched-chain keto acids (BCKAs) metabolites. Presently, at least 4 genes of BCKDHA, BCKDHB, DLD and DBT have been reported to cause MSUD. Furthermore, more than 265 mutations have been identified as the cause across different populations worldwide. Some studies have reported the data of gene mutations in Chinese people with MSUD. In this study, we present clinical characteristics and mutational analyses in five Chinese Han child with MSUD, which had been screened out by tandem mass spectrometry detection of amino acids in blood samples. High-throughput sequencing, Sanger sequence and real-time qualitative PCR were performed to detect and verify the genetic mutations. Six different novel genetic variants were validated in BCKDHB gene and BCKDHA gene, including c.523 T > C, c.659delA, c.550delT, c.863G > A and two gross deletions. Interestingly, 3 cases had identical mutation of BCKDHB gene (c.659delA). We predicted the pathogenicity and analyzed the clinical characteristics. The identification of these mutations in this study further expands the mutation spectrum of MSUD and contributes to prenatal molecular diagnosis of MSUD.
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Affiliation(s)
- Xiaomei Li
- Department of Neonatology, Qilu Children's Hospital of Shandong University, Jinan, Shandong, 250022, China
| | - Yali Yang
- Department of Rehabilitation, Qilu Children's Hospital of Shandong University, Jinan, Shandong, 250022, China
| | - Qing Gao
- Department of Genetics, Jinan Maternity and Child Care Hospital, Jinan, Shandong, 250001, China
| | - Min Gao
- Pediatric Research Institute, Qilu Children's Hospital of Shandong University, 23976 Jingshi Road, Jinan, Shandong, 250022, China
| | - Yvqiang Lv
- Pediatric Research Institute, Qilu Children's Hospital of Shandong University, 23976 Jingshi Road, Jinan, Shandong, 250022, China
| | - Rui Dong
- Pediatric Research Institute, Qilu Children's Hospital of Shandong University, 23976 Jingshi Road, Jinan, Shandong, 250022, China
| | - Yi Liu
- Pediatric Research Institute, Qilu Children's Hospital of Shandong University, 23976 Jingshi Road, Jinan, Shandong, 250022, China
| | - Kaihui Zhang
- Pediatric Research Institute, Qilu Children's Hospital of Shandong University, 23976 Jingshi Road, Jinan, Shandong, 250022, China.
| | - Zhongtao Gai
- Pediatric Research Institute, Qilu Children's Hospital of Shandong University, 23976 Jingshi Road, Jinan, Shandong, 250022, China.
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Boros Á, Pankovics P, Kőmíves S, Liptai Z, Dobner S, Ujhelyi E, Várallyay G, Zsidegh P, Bolba N, Reuter G. Co-infection with coxsackievirus A5 and norovirus GII.4 could have been the trigger of the first episode of severe acute encephalopathy in a six-year-old child with the intermittent form of maple syrup urine disease (MSUD). Arch Virol 2017; 162:1757-1763. [PMID: 28243803 DOI: 10.1007/s00705-017-3299-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 02/10/2017] [Indexed: 11/27/2022]
Abstract
In this case study, a co-infection with coxsackievirus A5 (family Picornaviridae) and norovirus GII.4 (family Caliciviridae) was detected by RT-PCR in a faecal sample from a six-year-old girl with symptoms of severe acute encephalopathy subsequently diagnosed as the intermittent form of maple syrup urine disease (MSUD). The two co-infecting viruses, which had been detected previously, appeared to have triggered the underlying metabolic disorder. Here, we describe the genotyping of the viruses, as well as the chronological course, laboratory test results, and clinical presentation of this case, which included recurrent vomiting without diarrhoea, metabolic acidosis, unconsciousness, seizure and circulatory collapse, but with a positive final outcome.
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Affiliation(s)
- Ákos Boros
- Regional Laboratory of Virology, National Reference Laboratory of Gastroenteric Viruses, ÁNTSZ Regional Institute of State Public Health Service, Pecs, Hungary
- Department of Medical Microbiology and Immunology, University of Pécs, Szigeti út 12, Pecs, 7624, Hungary
| | - Péter Pankovics
- Regional Laboratory of Virology, National Reference Laboratory of Gastroenteric Viruses, ÁNTSZ Regional Institute of State Public Health Service, Pecs, Hungary
- Department of Medical Microbiology and Immunology, University of Pécs, Szigeti út 12, Pecs, 7624, Hungary
| | - Sándor Kőmíves
- Szent István and Szent László Hospital, Budapest, Hungary
| | - Zoltán Liptai
- Szent István and Szent László Hospital, Budapest, Hungary
| | - Sarolta Dobner
- Szent István and Szent László Hospital, Budapest, Hungary
| | - Enikő Ujhelyi
- Szent István and Szent László Hospital, Budapest, Hungary
| | | | - Petra Zsidegh
- 1st Department of Paediatrics, Semmelweis University, Budapest, Hungary
| | - Nóra Bolba
- Regional Laboratory of Virology, National Reference Laboratory of Gastroenteric Viruses, ÁNTSZ Regional Institute of State Public Health Service, Pecs, Hungary
- Department of Medical Microbiology and Immunology, University of Pécs, Szigeti út 12, Pecs, 7624, Hungary
| | - Gábor Reuter
- Regional Laboratory of Virology, National Reference Laboratory of Gastroenteric Viruses, ÁNTSZ Regional Institute of State Public Health Service, Pecs, Hungary.
- Department of Medical Microbiology and Immunology, University of Pécs, Szigeti út 12, Pecs, 7624, Hungary.
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Abiri M, Talebi S, Uitto J, Youssefian L, Vahidnezhad H, Shirzad T, Salehpour S, Zeinali S. Co-existence of phenylketonuria either with maple syrup urine disease or Sandhoff disease in two patients from Iran: emphasizing the role of consanguinity. J Pediatr Endocrinol Metab 2016; 29:1215-1219. [PMID: 27682710 DOI: 10.1515/jpem-2016-0096] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Accepted: 08/29/2016] [Indexed: 11/15/2022]
Abstract
Most inborn errors of metabolism (IEMs) are inherited in an autosomal recessive manner. IEMs are one of the major concerns in Iran due to its extensive consanguineous marriages. Herein, we report two patients with two co-existent IEMs: a girl affected by classic phenylketonuria (PKU) and maple syrup urine disease (MSUD) and a male patient affected with Sandhoff disease and PKU, where Sandhoff disease was suspected due to the presence of a cherry-red spot in the eyes at 6 months which is unrelated to PKU. Sequencing of candidate genes in the first patient revealed one novel and three recurrent compound heterozygous mutations of p.Ser231Pro and p.Ala300Ser in the PAH gene and p.Glu330Lys and p.Arg170Cys mutations in the BCKDHB gene. Genetic testing results in the second patient showed previously reported homozygous mutations of p.Arg261Gln in the PAH and p.Arg533Cys mutation in the HEXB gene. Genetic testing confirmed the clinical diagnosis of both diseases in both patients. To the best of our knowledge; this is the first report of the co-existence of two distinct genetic disorders in two individuals from Iran. Co-existent different IEMs in patients complicated the clinical diagnosis and management of the diseases.
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Freeto S, Mason D, Chen J, Scott RH, Narayan SB, Bennett MJ. A rapid ultra performance liquid chromatography tandem mass spectrometric method for measuring amino acids associated with maple syrup urine disease, tyrosinaemia and phenylketonuria. Ann Clin Biochem 2016; 44:474-81. [PMID: 17761035 DOI: 10.1258/000456307781646012] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Background: Patients with inherited disorders of amino acid metabolism including maple syrup urine disease, tyrosinaemia and phenylketonuria on dietary management require frequent monitoring of disease-relevant plasma amino acids in order to optimize therapeutic benefit. Poorly controlled maple syrup urine disease in particular may result in catastrophic metabolic decompensation. Most methods for monitoring amino acid concentrations are time-consuming and have clinically impractical turnaround times, particularly when the required time to run standards and control samples is taken into account. Methods: We have analysed plasma amino acids using standard ion-exchange chromatography with ninhydrin detection in an amino acid analyser and compared the data with that obtained for the same samples using ultra-performance liquid chromatography (UPLCTM) separation with detection by tandem mass spectrometry. Results: The two methodologies compared very well for the measurement of six important amino acids with correlation coefficients greater than 0.96 for all. The time for sample preparation was longer for the UPLC methodology as batched derivatization and evaporation is required but UPLC-tandem mass spectrometry generated sample results every 8 min while conventional ion-exchange chromatography took almost 1 h per sample. Conclusion: UPLC-tandem mass spectrometry generates data that compares well with existing 'gold standard' methodologies but significantly reduces sample turnaround time. Decreasing the turnaround time for amino acid analyses is very likely to improve clinical care for patients with amino acid disorders as dietary adjustments can be made sooner.
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Sørensen LC, Rehman S, Lund AM. [Onset of hereditary metabolic encephalopathy can be seen after the neonatal period]. Ugeskr Laeger 2016; 178:V12151013. [PMID: 27238151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Maple syrup urine disease (MSUD) is an autosomal recessive metabolic disorder causing accumulation of the branched amino acids valin, isoleucin, leucin and their toxic metabolites resulting in ketoacidosis, progressive neurological deterioration and cerebral oedema. The classical form presents in the first days of life. In contrast, the intermittent form of MSUD presents later in childhood and is difficult to diagnose biochemically. Clinical awareness is important due to high mortality if not treated. We here present two cases with late-onset intermittent MSUD.
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Wang XL, Li CJ, Xing Y, Yang YH, Jia JP. Hypervalinemia and hyperleucine-isoleucinemia caused by mutations in the branched-chain-amino-acid aminotransferase gene. J Inherit Metab Dis 2015; 38:855-61. [PMID: 25653144 DOI: 10.1007/s10545-015-9814-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 01/09/2015] [Accepted: 01/12/2015] [Indexed: 10/24/2022]
Abstract
Valine, leucine, and isoleucine are essential branched chain amino acids (BCAAs). When BCAA metabolism is genetically impaired in human, serum levels of BCAA and/or their metabolites rise considerably, causing severe neurological dysfunction. The first step in BCAA catabolism is catalyzed by branched chain aminotransferase (BCAT). Hypervalinemia and hyperleucine-isoleucinemia caused by BCAT gene mutation in human have not been reported previously. A 25-year-old man presented with headache complaints and mild memory impairment for about six years. Brain MRI showed symmetric white matter abnormal signals. Metabolic studies revealed remarkably elevated plasma valine and leucine concentrations. Maple syrup urine disease (MSUD) diagnosis was not supported since all genes for the branched-chain α-keto acid dehydrogenase complex (BCKD) gene were normal. Interestingly, two heterogeneous BCAT2 gene mutations were found in the patient, including c.509G > A (p.Arg170Gln) and c.790G > A (p.Glu264Lys). In addition, c.509G > A (p.Arg170Gln) and c.790G > A (p.Glu264Lys) were found in his father and mother, respectively, suggesting an autosomal recessive disorder. BCAT2 functional studies demonstrated that the two BCAT2 gene mutations resulted in decreased BCAT2 enzyme activity. After treatment with vitamin B6, the levels of BCAA, especially valine were remarkably decreased and brain MRI lesions were improved. These findings suggest a new type of branched chain amino acid metabolism disorder. This rare case provides great insight into the further understanding of BCAA metabolism and its defect in human. BCAT2 gene mutations can cause hypervalinemia and hyperleucine-isoleucinemia, which are associated with brain white matter lesions.
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Affiliation(s)
- X L Wang
- Department of Neurology, Xuanwu Hospital, Capital Medical University, 45 Changchun Street, Beijing, 100053, People's Republic of China
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Thiboonboon K, Leelahavarong P, Wattanasirichaigoon D, Vatanavicharn N, Wasant P, Shotelersuk V, Pangkanon S, Kuptanon C, Chaisomchit S, Teerawattananon Y. An Economic Evaluation of Neonatal Screening for Inborn Errors of Metabolism Using Tandem Mass Spectrometry in Thailand. PLoS One 2015; 10:e0134782. [PMID: 26258410 PMCID: PMC4530882 DOI: 10.1371/journal.pone.0134782] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 07/10/2015] [Indexed: 11/21/2022] Open
Abstract
Background Inborn errors of metabolism (IEM) are a rare group of genetic diseases which can lead to several serious long-term complications in newborns. In order to address these issues as early as possible, a process called tandem mass spectrometry (MS/MS) can be used as it allows for rapid and simultaneous detection of the diseases. This analysis was performed to determine whether newborn screening by MS/MS is cost-effective in Thailand. Method A cost-utility analysis comprising a decision-tree and Markov model was used to estimate the cost in Thai baht (THB) and health outcomes in life-years (LYs) and quality-adjusted life year (QALYs) presented as an incremental cost-effectiveness ratio (ICER). The results were also adjusted to international dollars (I$) using purchasing power parities (PPP) (1 I$ = 17.79 THB for the year 2013). The comparisons were between 1) an expanded neonatal screening programme using MS/MS screening for six prioritised diseases: phenylketonuria (PKU); isovaleric acidemia (IVA); methylmalonic acidemia (MMA); propionic acidemia (PA); maple syrup urine disease (MSUD); and multiple carboxylase deficiency (MCD); and 2) the current practice that is existing PKU screening. A comparison of the outcome and cost of treatment before and after clinical presentations were also analysed to illustrate the potential benefit of early treatment for affected children. A budget impact analysis was conducted to illustrate the cost of implementing the programme for 10 years. Results The ICER of neonatal screening using MS/MS amounted to 1,043,331 THB per QALY gained (58,647 I$ per QALY gained). The potential benefits of early detection compared with late detection yielded significant results for PKU, IVA, MSUD, and MCD patients. The budget impact analysis indicated that the implementation cost of the programme was expected at approximately 2,700 million THB (152 million I$) over 10 years. Conclusion At the current ceiling threshold, neonatal screening using MS/MS in the Thai context is not cost-effective. However, the treatment of patients who were detected early for PKU, IVA, MSUD, and MCD, are considered favourable. The budget impact analysis suggests that the implementation of the programme will incur considerable expenses under limited resources. A long-term epidemiological study on the incidence of IEM in Thailand is strongly recommended to ascertain the magnitude of problem.
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Affiliation(s)
- Kittiphong Thiboonboon
- Health Intervention and Technology Assessment Program (HITAP), Ministry of Public Health, Nonthaburi, Thailand
- * E-mail:
| | - Pattara Leelahavarong
- Health Intervention and Technology Assessment Program (HITAP), Ministry of Public Health, Nonthaburi, Thailand
| | - Duangrurdee Wattanasirichaigoon
- Division of Medical Genetics, Department of Pediatrics, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Nithiwat Vatanavicharn
- Division of Medical Genetics, Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Pornswan Wasant
- Division of Medical Genetics, Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Vorasuk Shotelersuk
- Center of Excellence for Medical Genetics, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Suthipong Pangkanon
- Genetic Unit, Department of Pediatrics, The Queen Sirikit National Institute of Child Health, Department of Medical Services, Ministry of Public Health, Bangkok, Thailand
| | - Chulaluck Kuptanon
- Genetic Unit, Department of Pediatrics, The Queen Sirikit National Institute of Child Health, Department of Medical Services, Ministry of Public Health, Bangkok, Thailand
| | - Sumonta Chaisomchit
- Neonatal Screening Operation Centre, Department of Medical Science, Ministry of Public Health, Nonthaburi, Thailand
| | - Yot Teerawattananon
- Health Intervention and Technology Assessment Program (HITAP), Ministry of Public Health, Nonthaburi, Thailand
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Páez Rojas PL, Suarez Obando F. [GENETIC AND METABOLIC URGENCIES IN THE NEONATAL INTENSIVE CARE UNIT: MAPLE SYRUP URINE DISEASE]. NUTR HOSP 2015; 32:420-425. [PMID: 26262748 DOI: 10.3305/nh.2015.32.1.8996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023] Open
Abstract
Maple syrup urine disease (MSUD) is a hereditary disorder of branched chain amino/keto acid metabolism, caused by a decreased activity of the branched-chain alpha- ketoacid dehydrogenase complex (BCKAD), which leads to abnormal elevated plasma concentrations of branched-chain amino acids (BCAAs) clinically manifested as a heavy burden for Central Nervous system. The toxic accumulation of substrates promotes the development of a severe and rapidly progressive neonatal encephalopathy if treatment is not immediately given. This disorder has a specific medical management in acute phase in order to minimize mortality and morbidity. For all those reasons, it is important to include the MSUD as a possible diagnosis in a encephalopathic newborn. We present a colombian newborn with classical MSUD with fatal outcome as an example of metabolic emergency and a differential diagnosis in the encephalopathic newborn.
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Affiliation(s)
- Paola Liliana Páez Rojas
- Grupo de Nutrición, Genética y Metabolismo, Facultad de Medicina, Universidad el Bosque, Bogotá D.C., Colombia..
| | - Fernando Suarez Obando
- Grupo de Nutrición, Genética y Metabolismo, Facultad de Medicina, Universidad el Bosque, Bogotá D.C., Colombia..
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Hooft C, Carton D. Pediatric clinical aspects of aminoacidopathies. Monogr Hum Genet 2015; 6:50-63. [PMID: 4663915 DOI: 10.1159/000392666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Newborn screening programme expanded. Community Pract 2015; 88:5. [PMID: 25720200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
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Mroch A, Davis-Keppen L, Matthes C, Stein Q. Identification of a founder mutation for maple syrup urine disease in Hutterites. S D Med 2014; 67:141-143. [PMID: 24791375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Maple syrup urine disease (MSUD) is an organic acidemia detected on newborn screening. The condition has been reported with increased frequency in certain founder populations including Hutterites. We present a case of MSUD in a Hutterite boy. Mutation analysis was completed and identified a candidate founder mutation in the BCKDHB gene, specifically c.595_596delAG. Further testing of other Hutterites with MSUD is needed to determine whether additional mutations may exist.
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Michel MA, Raucourt E, Bednarek N, Garnotel R. [What disorders suspect following an increase of phenylalanine on newborn screening?]. Ann Biol Clin (Paris) 2014; 72:193-6. [PMID: 24736139 DOI: 10.1684/abc.2014.0942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023]
Abstract
Screening for PKU, in France, is made on the 3rd day of life by measuring the concentration of phenylalanine in dried blood spot samples. In this study, the goal was to examine the final diagnosis of patients who showed a hyperphenylalaninemia during newborn screening laboratory. Over a period of 11 years from 1 February 2002 to 31 January 2013, all newborns with a phenylalanine concentration increase (>180 μmol/L) have been identified and the cause of this increase was noted. Of the 165,113 newborns screened, hyperphenylalaninemia was identified in 90 patients during the newborn screening laboratory. During this period 35% of cases were due to classical phenylketonuria or hyperphenylalaninemia. In 4.4% of cases, increase concentrations were due to other diseases (biopterine deficiency, galactosemia, MSUD). However, 48.9% of high concentrations have not been confirmed by a second sample and 11% were children who died rapidely during their first days of life. The positive predictive value (PPV) of the test with a threshold of positivity >180 μmol/L was 40%. Our study showed that the positivity threshold of 180 μmol/L proposed by the Association française pour le dépistage et la prévention des handicaps de l'enfant (AFDPHE) provides a comprehensive detection of all phenylketonuria cases as well as mild hyperphenylalaninemia permanent and transient cases. Eventhough the use of a higher threshold would have the advantage of increasing the PPV of the test, none the less we would have missed out on some cases to follow.
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Affiliation(s)
- Marc-Antoine Michel
- Laboratoire de biologie et de recherche pédiatriques, American Memorial Hospital, CHU Reims, France
| | | | - Nathalie Bednarek
- ARCAMMHE, Alix de Champagne, CHU Reims, France, Service de néonatologie, Alix de Champagne, CHU Reims, France
| | - Roselyne Garnotel
- Laboratoire de biologie et de recherche pédiatriques, American Memorial Hospital, CHU Reims, France, ARCAMMHE, Alix de Champagne, CHU Reims, France
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Screening programme. Changes in the pipeline. Midwives 2014; 17:10. [PMID: 25328969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
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Abstract
Symptoms in patients with defects in amino acid catabolism and the urea cycle usually develop because of intoxication of accumulating metabolites. The cumulative prevalence of these disorders is considerable (at least>1:2000 newborns). Timely and correct intervention during the initial presentation and during later episodes is most important. Evaluation of metabolic parameters should be performed on an emergency basis in every patient with symptoms of unexplained metabolic crisis, intoxication, and/or unexplained encephalopathy. A substantial number of patients develop acute encephalopathy or chronic and fluctuating progressive neurological disease. The so-called cerebral organic acid disorders present with (progressive) neurological symptoms: ataxia, myoclonus, extrapyramidal symptoms, and "metabolic stroke." Important diagnostic clues, such as white matter abnormalities, cortical or cerebellar atrophy, and injury of the basal ganglia can be derived from cranial magnetic resonance imaging (MRI). Long-term neurological disease is common, particularly in untreated patients, and the manifestations are varied, the most frequent being (1) mental defect, (2) epilepsy, and (3) movement disorders. Successful treatment strategies are becoming increasingly available. They mostly require an experienced interdisciplinary team including a neuropediatrician and/or later on a neurologist.
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Affiliation(s)
- Georg F Hoffmann
- Department of General Pediatrics, University Children's Hospital Heidelberg, Heidelberg, Germany.
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Yang N, Han LS, Ye J, Qiu WJ, Zhang HW, Gao XL, Wang Y, Li XY, Xu H, Gu XF. [Clinical characteristics and analysis of mass spectrometric data in 33 patients with maple syrup urine disease]. Zhonghua Yi Xue Za Zhi 2012; 92:2839-2842. [PMID: 23290213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
OBJECTIVE To explore the clinical characteristics and the diagnostic method of maple syrup urine disease (MSUD). METHODS From January 2003 to December 2011, a total of 14 000 patients with suspected inherited metabolism diseases were tested. The blood levels of leucine and valine of these patients were detected by tandem mass spectrometry. The urinary level of branched-chain α-ketoacids was tested by gas chromatography-mass spectrometry. And the diagnosis was based on the elevated levels of leucine and valine in blood and branched-chain α-ketoacids in urine. RESULTS Thirty-three MSUD patients were confirmed. Their median age of initial visit was 0.17 years old (range: 7 days to 30 years old). The peak onset age of them was 2-30 days old, including 28 cases of neonatal onset (84.8%). The presenting symptoms of 28 cases were feeding difficulties (n=14), poor response, lethargy and seizures. Their median blood levels of leucine and valine (1901 (458-5804) and 600 (315-1617) µmol/L) were significantly higher than their normal levels ((50-300) and (60-250) µmol/L, both P<0.01). Their urinary levels of 2-OH-isovaleric acid, 2-keto-isovaleric acid, 2-keto-3-methylvaleric acid, 2-keto-isocaproic and acetylglycine (262.5 (5.4-624.3), 35.8 (1.9-156.0), 133.8 (7.4-611.5), 518.7 (17.2-2121.2) and 280.5 (11.0-1087.9) respectively) significantly higher than their normal levels (0, <0.1, 0, 0, <0.1 respectively, all P<0.01). In 5 intermittent MSUD patients, their blood levels of leucine and valine (402 (348-958) and 556 (322-808) µmol/L) were significantly higher than their normal levels (both P<0.01). The urinary level of 2-OH-isovaleric acid was significantly higher than its normal levels (P<0.01) while the urinary levels of other α-ketoacids were normal. CONCLUSIONS The confirmation of MSUD remains difficult because of a lack of specific clinical features. The detections of tandem mass spectrometry and gas chromatography-mass spectrometry may aid its early diagnosis.
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Affiliation(s)
- Nan Yang
- Department of Pediatric Endocrinology, Genetic & Metabolic Diseases, Shanghai Institute of Pediatric Research, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200092, China
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Manara R, Del Rizzo M, Burlina AP, Bordugo A, Citton V, Rodriguez-Pombo P, Ugarte M, Burlina AB. Wernicke-like encephalopathy during classic maple syrup urine disease decompensation. J Inherit Metab Dis 2012; 35:413-7. [PMID: 22350544 DOI: 10.1007/s10545-012-9456-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Revised: 01/20/2012] [Accepted: 01/24/2012] [Indexed: 10/28/2022]
Abstract
We describe a new neuroradiologic picture observed during metabolic decompensation in two maple syrup urine disease (MSUD) patients that resembles Wernicke encephalopathy (WE). Clinical observations and the review of the literature regarding WE and MSUD pathophysiology prompted us to hypothesize a pathogenic link between these two disorders. Based on these findings, clinicians and neuroradiologists should be aware of MSUD as a possible predisposing factor of WE in children.
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Affiliation(s)
- R Manara
- Division of Neuroradiology, University Hospital of Padua, Padua, Italy
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30
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Xu FL, Fan T, Duan JJ, Chen D. [Clinical analysis of organic acidemia in neonates from neonatal intensive care units]. Zhongguo Dang Dai Er Ke Za Zhi 2012; 14:336-339. [PMID: 22613102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
OBJECTIVE To study the clinical features of organic acidemia in neonates admitted to the intensive care unit. METHODS The clinical features of neonates from 15 neonatal intensive care units of Henan Province, who were diagnosed with congenital organic acidemia by gaschromatography-mass spectrometry (GC-MS) between June 2008 and August 2011 were retrospectively reviewed. RESULTS Fifty neonates of 287 high risk neonates were confirmed as having or highly suspected to have inborn errors of metabolism. Of the 50 cases, 32 cases were diagnosed with organic acidemia disease, including 28 cases of methylmalonic acidemia, 2 cases of propionic acidemia, 1 case of maple syrup urine disease and 1 case of isovaleric acldemla. In most cases, disease onset occurred in the first week after birth in most of cases (75%). Neonates whose symptoms occurred immediately after or within a few hours of birth presented with serious conditions. Clinical manifestations were various and mainly related to neurologic, respiratory and gastrointestinal symptoms such as poor response, coma, drowsiness, abnormal muscle tone, convulsions, polypnea, dyspnea, milk refusal, diarrhea and jaundice. Initial symptoms were non-specific and included dyspnea, poor response, milk refusal, lethargy and seizures. CONCLUSIONS Methylmalonic acidemia is a common inherited metabolic disease in the neonatal period. Clinical manifestations of organic acid metabolism abnormalities in neonates are atypical and early onset is associated with more serious conditions.
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Affiliation(s)
- Fa-Lin Xu
- Department of Neonatology, Zhengzhou University, Zhengzhou, China.
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31
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Qu SQ, Yang LC, Luan Z, Du K, Yang H. [Acute encephalopathy due to late-onset maple syrup urine disease in a school boy]. Zhongguo Dang Dai Er Ke Za Zhi 2012; 14:161-164. [PMID: 22433398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Maple syrup urine disease is a common amino acids metabolic disease. In most patients, onset occurs in the neonatal period and infancy. In this study, the case of a school boy with acute encephalopathy due to late-onset maple syrup urine disease is summarized. The boy (8.5 years) was admitted because of acute encephalopathy after suffering from infection for two days at the age of eight and a half years. Metabolic acidosis, hyperuricemia and decreased protein level in cerebrospinal fluid were found by general laboratory tests. Magnetic resonance imaging of the brain revealed signal intensity abnormalities in the bilateral cerebellum dentate nucleus, brainstem, thalamus, putamen, caudate nucleus and cortex of the cerebral hemispheres. On T1WI and T2WI scanning, hyperintensive signal was found. Blood leucine and valine were significantly elevated. Urinary 2-hydroxy isovaleric acid, 3-hydroxybutyric acid, 2-keto isovaleric acid, and 2-keto acid also increased. Both the blood amino acid and urine organic acid profiles led to the diagnosis of maple syrup urine disease. In the acute period, the patient was treated with a large dose of vitamin B1, glucose, L-carnitine and a protein-restrict diet. The patient's condition improved significantly after five days of treatment, and he recovered completely two days later. Afterwards, treatment with vitamin B1, L-carnitine and a protein-restrict diet (1 g/kg/day) was continued. One and a half months later, blood amino acids and urine organic acids returned to normal. Magnetic resonance imaging of the brain also indicated a great improvement. It was concluded that inborn metabolic disease should be considered in the patients with an onset similar to acute encephalopathy. Early diagnosis and proper treatment can prevent brain damage and improve prognosis.
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Affiliation(s)
- Su-Qing Qu
- Department of Pediatrics, Navy general Hospital, Beijing 100048, China
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Knerr I, Weinhold N, Vockley J, Gibson KM. Advances and challenges in the treatment of branched-chain amino/keto acid metabolic defects. J Inherit Metab Dis 2012; 35:29-40. [PMID: 21290185 PMCID: PMC4136412 DOI: 10.1007/s10545-010-9269-1] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2010] [Revised: 12/10/2010] [Accepted: 12/23/2010] [Indexed: 12/12/2022]
Abstract
Disorders of branched-chain amino/keto acid metabolism encompass diverse entities, including maple syrup urine disease (MSUD), the 'classical' organic acidurias isovaleric acidemia (IVA), propionic acidemia (PA), methylmalonic acidemia (MMA) and, among others, rarely described disorders such as 2-methylbutyryl-CoA dehydrogenase deficiency (MBDD) or isobutyryl-CoA dehydrogenase deficiency (IBDD). Our focus in this review is to highlight the biochemical basis underlying recent advances and ongoing challenges of long-term conservative therapy including precursor/protein restriction, replenishment of deficient substrates, and the use of antioxidants and anaplerotic agents which refill the Krebs cycle. Ongoing clinical assessments of affected individuals in conjunction with monitoring of disease-specific biochemical parameters remain essential. It is likely that mass spectrometry-based 'metabolomics' may be a helpful tool in the future for studying complete biochemical profiles and diverse metabolic phenotypes. Prospective studies are needed to test the effectiveness of adjunct therapies such as antioxidants, ornithine-alpha-ketoglutarate (OKG) or creatine in addition to specialized diets and to optimize current therapeutic strategies in affected individuals. With the individual life-time risk and degree of severity being unknown in asymptomatic individuals with MBDD or IBDD, instructions regarding risks for metabolic stress and fasting avoidance along with clinical monitoring are reasonable interventions at the current time. Overall, it is apparent that carefully designed prospective clinical investigations and multicenter cohort-controlled trials are needed in order to leverage that knowledge into significant breakthroughs in treatment strategies and appropriate approaches.
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Affiliation(s)
- Ina Knerr
- Children's and Adolescents' Hospital, Otto-Heubner Centrum, Pediatric Metabolic Unit, Charité - Universitätsmedizin, Berlin, Germany.
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Wamelink MMC, Roos B, Jansen EEW, Mulder MF, Gibson KM, Jakobs C. 4-Hydroxybutyric aciduria associated with catheter usage: a diagnostic pitfall in the identification of SSADH deficiency. Mol Genet Metab 2011; 102:216-7. [PMID: 20965758 PMCID: PMC3654524 DOI: 10.1016/j.ymgme.2010.10.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Revised: 10/01/2010] [Accepted: 10/01/2010] [Indexed: 10/19/2022]
Abstract
Succinic semialdehyde dehydrogenase deficiency is a slowly progressive to static neurological disorder featuring elevated concentrations of 4-hydroxybutyric acid in body fluids. We present two patients with elevated 4-hydroxybutyric acid in urine which was later shown to be linked to catheter usage.
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Affiliation(s)
- M M C Wamelink
- VU University Medical Center, Department of Clinical Chemistry, Metabolic Unit, Amsterdam, The Netherlands.
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34
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Ti WJ. Maple syrup urine disease in mainland China. J Pediatr Endocrinol Metab 2011; 24:857. [PMID: 22145494 DOI: 10.1515/jpem.2011.333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 09/11/2023]
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35
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Fernández-Guerra P, Navarrete R, Weisiger K, Desviat LR, Packman S, Ugarte M, Rodríguez-Pombo P. Functional characterization of the novel intronic nucleotide change c.288+9C>T within the BCKDHA gene: understanding a variant presentation of maple syrup urine disease. J Inherit Metab Dis 2010; 33 Suppl 3:S191-8. [PMID: 20431954 DOI: 10.1007/s10545-010-9077-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2010] [Revised: 02/25/2010] [Accepted: 03/08/2010] [Indexed: 11/26/2022]
Abstract
Mutations in any of the three different genes--BCKDHA, BCKDHB, and DBT--encoding for the E1α, E1β, and E2 catalytic components of the branched-chain α-ketoacid dehydrogenase complex can cause maple syrup urine disease (MSUD). Disease severity ranges from the classic to the mildest variant types and precise genotypes, mostly based on missense mutations, have been associated to the less severe presentations of the disease. Herein, we examine the consequences at the messenger RNA (mRNA) level of the novel intronic alteration c.288+9C>T found in heterozygous fashion in a BCKDHA variant MSUD patient who also carries the nucleotide change c.745G>A (p.Gly249Ser), previously described as a severe change. Direct analysis of the processed transcripts from the patient showed--in addition to a low but measurable level of normal mRNA product--an aberrantly spliced mRNA containing a 7-bp fragment of intron 2, which could be rescued when the patient's cells were treated with emetine. This aberrant transcript with a premature stop codon would be unstable, supporting the possible activation of nonsense-mediated mRNA decay pathway. Consistent with this finding, minigene splicing assays demonstrated that the point mutation c.288+9C>T is sufficient to create a cryptic splice site and cause the observed 7-bp insertion. Furthermore, our results strongly suggest that the c.288+9C>T allele in the patient generates both normal and aberrant transcripts that could sustain the variant presentation of the disease, highlighting the importance of correct genotyping to establish genotype-phenotype correlations and as basis for the development of therapeutic interventions.
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Affiliation(s)
- Paula Fernández-Guerra
- Centro de Diagnóstico de Enfermedades Moleculares, Dpto Biol Mol., Centro Biología Molecular-SO UAM-CSIC, Universidad Autónoma de Madrid, Campus Cantoblanco, F Ciencias Modulo 10, 28049, Madrid, Spain
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36
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Quintana E, Pineda M, Font A, Vilaseca MA, Tort F, Ribes A, Briones P. Dihydrolipoamide dehydrogenase (DLD) deficiency in a Spanish patient with myopathic presentation due to a new mutation in the interface domain. J Inherit Metab Dis 2010; 33 Suppl 3:S315-9. [PMID: 20652410 DOI: 10.1007/s10545-010-9169-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2010] [Revised: 06/30/2010] [Accepted: 07/01/2010] [Indexed: 11/29/2022]
Abstract
We present a 32-year-old patient who, from age 7 months, developed photophobia, left-eye ptosis and progressive muscular weakness. At age 7 years, she showed normal psychomotor development, bilateral ptosis and exercise-induced weakness with severe acidosis. Basal blood and urine lactate were normal, increasing dramatically after effort. PDHc deficiency was demonstrated in muscle and fibroblasts without detectable PDHA1 mutations. Ketogenic diet was ineffective, however thiamine gave good response although bilateral ptosis and weakness with acidosis on exercise persisted. Recently, DLD gene analysis revealed a homozygous missense mutation, c.1440 A>G (p.I480M), in the interface domain. Both parents are heterozygous and DLD activity in the patient's fibroblasts is undetectable. The five patients that have been reported with DLD-interface mutations suffered fatal deteriorations. Our patient's disease is milder, only myopathic, more similar to that due to mutation p.G229C in the NAD(+)-binding domain. Two of the five patients presented mutations (p.D479V and p.R482G) very close to the present case (p.I480M). Despite differing degrees of clinical severity, all three had minimal clues to DLD deficiency, with occasional minor increases in α-ketoglutarate and branched-chain amino acids. In the two other patients, hypertrophic cardiomyopathy was a significant feature that has been attributed to moonlighting proteolytic activity of monomeric DLD, which can degrade other mitochondrial proteins, such as frataxin. Our patient does not have cardiomyopathy, suggesting that p.I480M may not affect the DLD ability to dimerize to the same extent as p.D479V and p.R482G. Our patient, with a novel mutation in the DLD interface and mild clinical symptoms, further broadens the spectrum of this enzyme defect.
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Affiliation(s)
- Ester Quintana
- Sección de Errores Congénitos del Metabolismo, Servicio de Bioquímica y Genética Molecular, Hospital Clínic, Instituto de Bioquímica Clínica, Barcelona, Spain
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37
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Chen Z, Luo F, Wu XJ, Shi LP. [Maple syrup urine disease of neonates: report of two cases and review of literature]. Zhonghua Er Ke Za Zhi 2010; 48:680-684. [PMID: 21092528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
OBJECTIVE To analyze and summarize clinical manifestation of maple syrup urine disease (MSUD) of neonates. METHODS Data of two cases with neonatal MSUD and the reports of 15 cases seen in the past 15 years in China were reviewed and analyzed. RESULTS There was an increasing number of reports of cases with neonatal MSUD. All the 17 cases had the symptom of poor feeding between 3 h and 8 d after birth; 7 cases had family history; 14 cases showed progressive neurologic signs. Odor of maple syrup occurred in 8 cases. Blood levels of branched-chain amino acids (BCAA) significantly increased in 13 cases and 6 neonates were diagnosed using tandem mass spectrometry. Urinary levels of BCAA and metabolite elevated in 12 cases and 5 neonates were diagnosed using gas chromatography-mass spectrometry. MRI/CT demonstrated abnormal signal in 10 cases. Twelve cases died or their parents gave up treatment and one case had cerebral palsy; 4 cases were treated with BCAA-free formula milk and showed improved outcome. CONCLUSION Newborns with MSUD often had early appeared non-specific symptoms with poor feeding and lethargy, most cases later showed an odor resembling maple syrup and neurologic signs. For patients who were suspected of having MSUD, blood and urine concentrations of BCAA should be tested for early diagnosis. Specific MRI edema signal from brain suggests the possibility of MSUD. Early intervention and treatment after diagnosis, with compliance of parents, would improve the patient's outcome.
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Affiliation(s)
- Zheng Chen
- Department of Neonatal Intensive Care Unit, Zhejiang University School of Medicine, Hangzhou 310003, China
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Quental S, Vilarinho L, Martins E, Teles EL, Rodrigues E, Diogo L, Garcia P, Eusébio F, Gaspar A, Sequeira S, Amorim A, Prata MJ. Incidence of maple syrup urine disease in Portugal. Mol Genet Metab 2010; 100:385-7. [PMID: 20466570 DOI: 10.1016/j.ymgme.2010.04.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2010] [Accepted: 04/14/2010] [Indexed: 10/19/2022]
Abstract
Maple syrup urine disease is an autosomal recessive disorder of branched-chain amino acids metabolism with a worldwide frequency of 1/185,000 live newborns. In Portugal, the incidence of the disease has not been assessed. Based on the review of the cases diagnosed by tandem mass spectrometry an incidence of 1/86,800 live newborns was estimated in Portugal, indicating that the disease is more frequent in this country than reported in most populations.
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Affiliation(s)
- Sofia Quental
- IPATIMUP - Institute of Pathology and Molecular Immunology, University of Porto, Portugal.
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Puckett RL, Lorey F, Rinaldo P, Lipson MH, Matern D, Sowa ME, Levine S, Chang R, Wang RY, Abdenur JE. Maple syrup urine disease: further evidence that newborn screening may fail to identify variant forms. Mol Genet Metab 2010; 100:136-42. [PMID: 20307994 DOI: 10.1016/j.ymgme.2009.11.010] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2009] [Accepted: 11/30/2009] [Indexed: 11/29/2022]
Abstract
Newborn screening (NBS) by tandem mass spectrometry (MS/MS) has allowed for early detection and initiation of treatment in many patients with maple syrup urine disease (MSUD) (OMIM 248600), however, a recent report suggests that variants forms may be missed. Information on these patients is limited. We present clinical, biochemical and molecular information on patients with variant forms of MSUD not detected by the California Newborn Screening Program. Between July 2005 and July 2009, 2200,000 newborns were screened in California by MS/MS. Seventeen cases of MSUD were detected and three (two siblings) were missed. Additionally, the NBS cards of two siblings with late onset MSUD, who were born pre-expanded NBS, were retrospectively analyzed. None of the five patients met criteria to be considered presumptive positive for MSUD (leucine>200micromol/L and a ratio of leucine/alanine>or=1.5). Alloisoleucine (allo-ile) was subsequently analyzed in the NBS cards of all five patients, two of whom were found to have elevated levels. The proband in each family was diagnosed following symptoms triggered by an intercurrent illness or increased protein intake. At diagnosis, leucine levels ranged between 561 and >4528micromol/L, and allo-ile ranged from 137 to 239micromol/L. Two affected siblings had normal plasma amino acids when asymptomatic; however, their biochemical profiles were diagnostic of MSUD during intercurrent illnesses. The median age at diagnosis of all patients was one year (range 0.8-6.7). Heterozygous BCKDHB (E1beta) mutations (c.832G>A/c.970C>T) were identified in one family and a homozygous DBT (E2) sequence variant (c.1430 T>G) in another. The third family had one identifiable DBT mutation (c.827T>G), however, a second mutation was not detected. This report provides further evidence that NBS by MS/MS is unable to detect all cases of MSUD. Second-tier testing with allo-ile may improve sensitivity; however, some children with variant forms will invariably be missed.
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Affiliation(s)
- R L Puckett
- Division of Metabolic Disorders, CHOC Children's, Orange, CA 92868, USA
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Tammachote R, Tongkobpetch S, Desudchit T, Suphapeetiporn K, Shotelersuk V. Prenatal diagnosis of a novel mutation, c.529C>T (p.Q177X), in the BCKDHA gene in a family with maple syrup urine disease. J Inherit Metab Dis 2009; 32 Suppl 1:S33-6. [PMID: 19240989 DOI: 10.1007/s10545-009-1022-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2008] [Revised: 12/19/2008] [Accepted: 01/12/2009] [Indexed: 10/21/2022]
Abstract
Maple syrup urine disease (MSUD) is an autosomal recessive metabolic disorder caused by defective activity of the branched-chain alpha-keto-acid dehydrogenase (BCKD) complex. The disease-causing mutations can affect the BCKDHA, BCKDHB or DBT genes encoding for the E1a, E1b, and E2 subunits, respectively, of the BCKD complex. Here we report a girl who first presented to our clinic at 4 years of age with profound mental retardation. A diagnosis of MSUD was subsequently made based on the results of plasma amino acid analysis. Mutation analysis confirmed that she was homozygous for a novel mutation, c.529C>T (p.Q177X) in BCKDHA, while both parents, who were first cousins, were heterozygous. This enabled us to give an option of prenatal diagnosis to the parents. The prenatal testing for MSUD was performed during the mother's subsequent pregnancy and revealed that the fetus was heterozygous for the mutation. The healthy male neonate was born and his genotype was tested by restriction enzyme analysis, which confirmed the result of the prenatal testing. In summary, a late diagnosis of MSUD in patients without an unusual odour could occur especially in countries without neonatal screening programs as seen in the index patient. Mutation detection was, however, still beneficial to the family since prenatal testing could be performed in subsequent pregnancies. In addition, a novel mutation was found, expanding the mutation spectrum of this disease.
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Affiliation(s)
- R Tammachote
- Department of Botany, Faculty of Science, Chulalongkorn University, Bangkok, Thailand
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Ling Y, Qian Y, Peng XL, Wang K, Gao JJ, Xu AQ. [Maple syrup urine disease in a neonate]. Zhongguo Dang Dai Er Ke Za Zhi 2009; 11:945-946. [PMID: 20113671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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42
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Jiang FZ, Cui QL, Jiang JH. [A case report of maple syrup urine disease]. Zhongguo Dang Dai Er Ke Za Zhi 2009; 11:599-600. [PMID: 19651002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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43
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Dutov AA, Nikitin DA, Belen'kova EV, Gatiiatov IF, Titova IL. [HPLC for the diagnosis and monitoring of phenylketonuria and ketoaciduria]. Klin Lab Diagn 2009:13-15. [PMID: 19537111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A simple, rapid, and sensitive HPLC is proposed to test six amino acids in plasma/serum. Deproteinization was carried out with acetonitrile; derivation was made with the orthophthalic aldehyde 2-mercaptoethanol. Separation was accompanied on a Chromolith (Merck), 4.6 mm in size, with monolytic reverse-phase silica gel in the isocratic mode with ultraviolet detection at 230 nm. The eluent contained a 50% mixture of methanol-acetonitrile-isopropanol (90:5:5, v/v/v) and 50% 0.01 M phosphate buffer (pH 6.7); flow rate 1000 ul/min; pressure 42 bars. Complete separation lasted at least 10 min. The detection limit was about 1 ng for phenylalanine, leucine, and isoleucine and less than 0.5 ng for tryptophan, valine, and methionine at a signal/noise ratio of 3.0. The simplicity, reproducibility, and sufficient sensitivity of the technique along with the feasibility of its application on standard chromatographic equipment (an isocratic pump and a ultraviolet detector) make it suitable for routine clinical application.
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Harty S, King MD, McCoy B, Costigan D, Treacy EP. Sensory-motor polyneuropathy occurring in variant maple syrup urine disease. J Inherit Metab Dis 2008; 31 Suppl 2:S209-11. [PMID: 18855118 DOI: 10.1007/s10545-008-0751-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2007] [Revised: 07/09/2008] [Accepted: 07/15/2008] [Indexed: 11/24/2022]
Abstract
Maple syrup urine disease (MSUD; OMIM 248600) results from an inherited deficiency of the branched-chain ketoacid dehydrogenase (BCKD) complex. Approximately 20% of patients with BCKD deficiency are non-classic variants of MSUD with differing clinical severity. Outcomes for this cohort are generally favourable; episodes of metabolic decompensation do not appear to correlate with adverse events if acute management is promptly provided. A case of predominantly axonal sensory-motor neuropathy following metabolic decompensation which persisted for a number of months is presented in an adolescent girl with variant (intermediate type) MSUD. EMG and nerve conduction studies suggested a pre-existent asymptomatic chronic neuropathy, exacerbated by the acute decompensation. Peak leucine concentration at decompensation was 1083 μmol/L. The patient had laboratory signs of secondary mitochondrial respiratory chain dysfunction at presentation. She had been on a moderate dose of thiamine prior to decompensation; thiamine and pyridoxine blood concentrations were normal. This, to our knowledge, is the first report of a neuropathy presenting in a patient with a decompensation of variant MSUD. We propose that this presentation resembles the intermittent neuropathy observed in pyruvate dehydrogenase deficiency and may reflect secondary inhibition of pyruvate dehydrogenase activity by MSUD metabolites.
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Affiliation(s)
- S Harty
- National Centre for Inherited Metabolic Disorders, Children's University Hospital, Temple St., Dublin 1, Ireland
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Lee JY, Chiong MA, Estrada SC, Cutiongco-De la Paz EM, Silao CLT, Padilla CD. Maple syrup urine disease (MSUD)--clinical profile of 47 Filipino patients. J Inherit Metab Dis 2008; 31 Suppl 2:S281-5. [PMID: 18989748 DOI: 10.1007/s10545-008-0859-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2007] [Revised: 08/20/2008] [Accepted: 09/11/2008] [Indexed: 10/21/2022]
Abstract
Maple syrup urine disease (MSUD) is a very rare disorder of branched-chain amino acid metabolism. However, it is the most common inborn error of metabolism in the Philippines. We present a retrospective review of 21 patients diagnosed with MSUD between 1999 and 2004. The patients presented clinically between 2 and 14 days of life (mean 5 days) and the diagnosis of MSUD was established between 6 days and 11 months of age (mean 39 days). The classical burnt sugar odour was noted in the majority of patients (81%). The diagnosis of MSUD was initially based on clinical suspicion and confirmed biochemically by measurement of leucine/isoleucine levels by thin-layer chromatography. The acute management included removal of accumulated branched-chain amino acids by peritoneal dialysis in 62% of the patients. Mortality rate of this group of patients was 24% and follow-up rate was 87%. We compared this series with a previously reported series of 26 patients to determine whether diagnosis and the management of MSUD improved over the two periods. Four cases have been diagnosed early since 1992, the majority of whom had the classic form of MSUD with the onset of symptoms in the first two weeks of life. A small subset of patients with early nonspecific symptoms was diagnosed much later owing to a low-level clinical suspicion among clinicians. Overall, however, there appears to be a small but general trend towards earlier diagnosis, reduced mortality and long-term follow up in the later series. Although we are able to diagnose and manage MSUD in the Philippines, we recognize that the clinical outcome remains poor and is due mainly to late referral of cases and inadequate long-term management. In the Philippines, we recommend that all newborns who are considered to be septic, have feeding difficulties, fail to regain their birth weight or present with any other symptoms suggestive of MSUD be evaluated in the first instance by analysis of urine for ketones and if they are positive have blood collected and sent to our laboratory for leucine/isoleucine measurement.
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Affiliation(s)
- J Y Lee
- Metabolic Services, Genetic Health Services Victoria, Royal Children's Hospital, Melbourne, Australia
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Quental S, Martins E, Vilarinho L, Amorim A, João Prata M. Maple syrup urine disease due to a new large deletion at BCKDHA caused by non-homologous recombination. J Inherit Metab Dis 2008; 31 Suppl 2:S457-60. [PMID: 19085071 DOI: 10.1007/s10545-008-1046-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2008] [Revised: 10/22/2008] [Accepted: 10/24/2008] [Indexed: 11/24/2022]
Abstract
Maple syrup urine disease (MSUD) is a rare disorder of branched-chain amino acid (BCAA) metabolism caused by the defective function of branched-chain α-ketoacid dehydrogenase complex (BCKD). Many MSUD-causing mutations have already been described in genes that encode the complex (BCKDHA, BCKDHB and DBT), but up to now only four large deletions are known, all located in the DBT gene. In a previous study we identified a Portuguese MSUD patient with a homozygous deletion of exons 2, 3 and 4 at the BCKDHA gene; however, the corresponding breakpoints and, consequently, the exact deletion extension were not identified. Here, using long-range PCR and sequencing methodologies we were able to refine the characterization of this gross rearrangement. A genomic DNA loss of about 13.8 kb was detected, starting at intron 1 and ending at intron 4, thus encompassing exons 2, 3 and 4. Molecular characterization showed that the deletion junction contained a short sequence whose motif was CGGG. Since this motif is present in introns 1 and 4 of normal genomic DNA, we have hypothesized that non-homologous recombination was the mechanism underlying the identified large deletion, within which the CGGG could be derived either from intron 1 or from intron 4.
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Affiliation(s)
- S Quental
- IPATIMUP - Institute of Pathology and Molecular Immunology of University of Porto, Rua Dr Roberto Frias s/n, 4200-465, Porto, Portugal.
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Pangkanon S, Charoensiriwatana W, Sangtawesin V. Maple syrup urine disease in Thai infants. J Med Assoc Thai 2008; 91 Suppl 3:S41-S44. [PMID: 19255991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Maple syrup urine disease (MSUD) is a rare inborn error of metabolism, caused by a deficiency in activity of the branched chain alpha-keto acid dehydrogenase impairing the degradation of the branched-chain amino acids (leucine, isoleucine and valine). Classic MSUD usually manifests in the neonatal period with poor feeding, vomiting, lethargy, muscular hypertonicity, seizure, coma and death. Thirteen cases of classic MSUD were diagnosed from 1997-2007 at the Queen Sirikit National Institute of Child Health. All cases presented in the neonatal period. The onset of symptoms ranged from 3 to 20 days (median 8 days). The time taken to make the diagnosis ranged from 18 to 356 days (median 55 days). The diagnosis was accomplished by clinical diagnosis and confirmed by detecting abnormal levels of amino acids in the blood and organic acids in the urine. Clinical manifestations were non-specific such as poor suck, weak cry, drowsiness and seizures. Majority of cases were initially diagnosed as sepsis and/or meningitis. All patients had neurological sequelae and psychomotor retardation. This results show the need for increase awareness of metabolic disorder such as MSUD and the requirement for early detection and treatment to ensure a better outcome.
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Affiliation(s)
- Suthipong Pangkanon
- Genetic Unit, Department ofPediatrics, Queen Sirikit National Institute of Child Health, College of Medicine, Rangsit University, Bangkok, Thailand.
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Matern D, Tortorelli S, Oglesbee D, Gavrilov D, Rinaldo P. Reduction of the false-positive rate in newborn screening by implementation of MS/MS-based second-tier tests: the Mayo Clinic experience (2004-2007). J Inherit Metab Dis 2007; 30:585-92. [PMID: 17643193 DOI: 10.1007/s10545-007-0691-y] [Citation(s) in RCA: 154] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2007] [Revised: 06/08/2007] [Accepted: 06/12/2007] [Indexed: 11/26/2022]
Abstract
The continued expansion of newborn screening programmes to include additional conditions increases the responsibility of newborn screening laboratories to provide testing with the highest sensitivity and specificity to allow for identification of affected patients while minimizing the false-positive rate. Some assays and analytes are particularly problematic. Over recent years, our laboratory tried to improve this situation by developing second-tier tests to reduce false-positive results in the screening for congenital adrenal hyperplasia (CAH), tyrosinaemia type I, methylmalonic acidaemias, homocystinuria, and maple syrup urine disease (MSUD). Beginning in 2004, this approach was applied to Mayo's newborn screening programme and resulted in a false-positive rate of 0.09%, a positive predictive value of 41%, and a positive detection rate of 1 affected case in 1672 babies screened.
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Affiliation(s)
- D Matern
- Biochemical Genetics Laboratory, Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA.
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Darvish M, Ebrahimi SA, Ghadam P. Development of micellar electro kinetic chromatography for the separation and quantitation of L-valine, L-leucine, L-isoleucin and L-phenylalanine in human plasma and comparison with HPLC. Pak J Biol Sci 2007; 10:2436-2441. [PMID: 19070110 DOI: 10.3923/pjbs.2007.2436.2441] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Phenylketonuria (PKU) and Maple Syrup Urine Disease (MSUD) are two inborn metabolic diseases which are carried by autosomal recessive genes in man. These genetic errors result in accumulation of phenylalanine (in PKU) or valine, leucine and isoluecin (in MSUD). At high concentrations, amongst other problems, these amino acids cause mental retardation. However if detected early after birth, using special diets and other forms of therapy, mental abnormalities can be prevented. As a result in many countries screening of infants for MSUD and PKU, by measuring plasma amino acids has become a routine neonatal test. Capillary Electrophoresis (CE) assays have a number of advantages over the traditional chromatography techniques (such as GC or HPLC). These include low cost, high speed of analysis and high resolution. These characteristics, make CE an ideal method for the screening of inborn errors of metabolism. We developed a CE assay based on pre-column derivatisation of amino acids with phenylisothiocyanate. This conjugate has strong absorbance at 254 nm. CE was carried out using a Spectraphoresis 1000 instrument, fitted with 40 cm of a 25 microm capillary, at 17 degrees C. A running voltage of 18KV was used to separate the amino acid mixture in an electrophoretic buffer containing 45 mM imidazole, 6 mM borate and 208 mM SDS, fixed at pH 9 with 2-N-morpholino ethane sulfonic acid. The assay was calibrated using various concentrations of amino acid standards. LOD, LOQ, recovery, inter-day and intra-day variations of the assay were determined. Also, levels of the 4 amino acids in normal and abnormal plasma were determined and compared with HPLC.
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Affiliation(s)
- M Darvish
- Department of Biochemistry, Alzahra University, Iran
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