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Bisello G, Saris CG, Franchini R, Verbeek MM, Willemsen MA, Perduca M, Bertoldi M. An attenuated, adult case of AADC deficiency demonstrated by protein characterization. Mol Genet Metab Rep 2024; 39:101071. [PMID: 38524666 PMCID: PMC10958467 DOI: 10.1016/j.ymgmr.2024.101071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 03/10/2024] [Accepted: 03/10/2024] [Indexed: 03/26/2024] Open
Abstract
A case of an adult with borderline AADC deficiency symptoms is presented here. Genetic analysis revealed that the patient carries two AADC variants (NM_000790.3: c.1040G > A and c.679G > C) in compound heterozygosis, resulting in p.Arg347Gln and p.Glu227Gln amino acid alterations. While p.Arg347Gln is a known pathogenic variant, p.Glu227Gln is unknown. Combining clinical features to bioinformatic and molecular characterization of the AADC protein population of the patient (p.Arg347Gln/p.Arg347Gln homodimer, p.Glu227Gln/p.Glu227Gln homodimer, and p.Glu227Gln/p.Arg347Gln heterodimer), we determined that: i) the p.Arg347Gln/p.Arg347Gln homodimer is inactive since the alteration affects a catalytically essential structural element at the active site, ii) the p.Glu227Gln/p.Glu227Gln homodimer is as active as the wild-type AADC since the alteration occurs at the surface and does not change the chemical nature of the amino acid, and iii) the p.Glu227Gln/p.Arg347Gln heterodimer has a catalytic efficiency 75% that of the wild-type since only one of the two active sites is compromised, thus demonstrating a positive complementation. By this approach, the molecular basis for the mild presentation of the disease is provided, and the experience made can also be useful for personalized therapeutic decisions in other mild AADC deficiency patients. Interestingly, in the last few years, many previously undiagnosed or misdiagnosed patients have been identified as mild cases of AADC deficiency, expanding the phenotype of this neurotransmitter disease.
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Affiliation(s)
- Giovanni Bisello
- Department of Neuroscience, Biomedicine and Movement Sciences, Section of Biochemistry, University of Verona, Strada Le Grazie 8, 37134 Verona, Italy
| | - Christiaan G.J. Saris
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Geert Grooteplein 10, 6525 GA Nijmegen, the Netherlands
| | - Rossella Franchini
- Department of Neuroscience, Biomedicine and Movement Sciences, Section of Biochemistry, University of Verona, Strada Le Grazie 8, 37134 Verona, Italy
| | - Marcel M. Verbeek
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Geert Grooteplein 10, 6525 GA Nijmegen, the Netherlands
- Translational Metabolic Laboratory, Department of Human Gentics, Radboud University Medical Centre, Geert Grooteplein 10, 6525 GA Nijmegen, the Netherlands
| | - Michel A.A.P. Willemsen
- Department of Pediatric Neurology, Radboud University Medical Centre, Geert Grooteplein 10, 6525 GA Nijmegen, the Netherlands
| | - Massimiliano Perduca
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy
| | - Mariarita Bertoldi
- Department of Neuroscience, Biomedicine and Movement Sciences, Section of Biochemistry, University of Verona, Strada Le Grazie 8, 37134 Verona, Italy
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Santa Paola S, Di Blasi FD, Borgione E, Lo Giudice M, Giuliano M, Pettinato R, Di Stefano V, Brighina F, Lupica A, Scuderi C. Aromatic L-Amino Acid Decarboxylase Deficiency: A Genetic Screening in Sicilian Patients with Neurological Disorders. Genes (Basel) 2024; 15:134. [PMID: 38275615 PMCID: PMC10815063 DOI: 10.3390/genes15010134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 01/09/2024] [Accepted: 01/19/2024] [Indexed: 01/27/2024] Open
Abstract
Aromatic L-amino acid decarboxylase deficiency (AADCd) is a rare autosomal recessive neurometabolic disorder caused by AADC deficiency, an enzyme encoded by the DDC gene. Since the enzyme is involved in the biosynthesis of serotonin and dopamine, its deficiency determines the lack of these neurotransmitters, but also of norepinephrine and epinephrine. Onset is early and the key signs are hypotonia, movement disorders (oculogyric crises, dystonia and hypokinesia), developmental delay and autonomic dysfunction. Taiwan is the site of a potential founder variant (IVS6+4A>T) with a predicted incidence of 1/32,000 births, while only 261 patients with this deficit have been described worldwide. Actually, the number of affected persons could be greater, given that the spectrum of clinical manifestations is broad and still little known. In our study we selected 350 unrelated patients presenting with different neurological disorders including heterogeneous neuromuscular disorders, cognitive deficit, behavioral disorders and autism spectrum disorder, for which the underlying etiology had not yet been identified. Molecular investigation of the DDC gene was carried out with the aim of identifying affected patients and/or carriers. Our study shows a high frequency of carriers (2.57%) in Sicilian subjects with neurological deficits, with a higher concentration in northern and eastern Sicily. Assuming these data as representative of the general Sicilian population, the risk may be comparable to some rare diseases included in the newborn screening programs such as spinal muscular atrophy, cystic fibrosis and phenylketonuria.
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Affiliation(s)
- Sandro Santa Paola
- Unit of Neuromuscular Diseases, Oasi Research Institute-IRCCS, Via Conte Ruggero 73, 94018 Troina, Italy; (E.B.); (M.L.G.); (M.G.); (C.S.)
| | | | - Eugenia Borgione
- Unit of Neuromuscular Diseases, Oasi Research Institute-IRCCS, Via Conte Ruggero 73, 94018 Troina, Italy; (E.B.); (M.L.G.); (M.G.); (C.S.)
| | - Mariangela Lo Giudice
- Unit of Neuromuscular Diseases, Oasi Research Institute-IRCCS, Via Conte Ruggero 73, 94018 Troina, Italy; (E.B.); (M.L.G.); (M.G.); (C.S.)
| | - Marika Giuliano
- Unit of Neuromuscular Diseases, Oasi Research Institute-IRCCS, Via Conte Ruggero 73, 94018 Troina, Italy; (E.B.); (M.L.G.); (M.G.); (C.S.)
| | - Rosa Pettinato
- Unit of Pediatrics and Medical Genetics, Oasi Research Institute-IRCCS, Via Conte Ruggero 73, 94018 Troina, Italy;
| | - Vincenzo Di Stefano
- Department of Biomedicine, Neuroscience and Advanced Diagnostic (BIND), University of Palermo, Via del Vespro, 143, 90127 Palermo, Italy; (V.D.S.); (F.B.); (A.L.)
| | - Filippo Brighina
- Department of Biomedicine, Neuroscience and Advanced Diagnostic (BIND), University of Palermo, Via del Vespro, 143, 90127 Palermo, Italy; (V.D.S.); (F.B.); (A.L.)
| | - Antonino Lupica
- Department of Biomedicine, Neuroscience and Advanced Diagnostic (BIND), University of Palermo, Via del Vespro, 143, 90127 Palermo, Italy; (V.D.S.); (F.B.); (A.L.)
| | - Carmela Scuderi
- Unit of Neuromuscular Diseases, Oasi Research Institute-IRCCS, Via Conte Ruggero 73, 94018 Troina, Italy; (E.B.); (M.L.G.); (M.G.); (C.S.)
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Cursio I, Siliquini S, Carducci C, Bisello G, Mastrangelo M, Leuzzi V, Bertoldi M, Marini C. Case report: Childhood epilepsy and borderline intellectual functioning hiding an AADC deficiency disorder associated with compound heterozygous DDC gene pathogenic variants. Front Neurol 2023; 14:1284339. [PMID: 38116105 PMCID: PMC10729769 DOI: 10.3389/fneur.2023.1284339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 10/31/2023] [Indexed: 12/21/2023] Open
Abstract
Aromatic L-amino acid decarboxylase (AADC) deficiency is a rare autosomal recessive neurometabolic disorder leading to severe combined serotonin, dopamine, norepinephrine, and epinephrine deficiency. We report on a female patient with borderline functioning and sporadic clear-cut focal to bilateral seizures from age 10 years. A neuropsychological assessment highlighted a mild impairment in executive functions, affecting attention span and visual-spatial abilities. Following the diagnosis of epilepsy with a presumed genetic etiology, we applied a diagnostic approach inclusive of a next-generation sequencing (NGS) gene panel, which uncovered two variants in trans in the DOPA decarboxylase (DDC) gene underlying an AADC deficiency. This compound heterozygous genotype was associated with a mild reduction of homovanillic acid, a low level of the norepinephrine catabolite, and a significant reduction of 5-hydroxyindoleacetic acid in cerebrospinal fluid. Remarkably, 3-O-methyldopa (3-OMD) and 5-hydroxytryptophan were instead increased. During the genetically guided re-evaluation process, some mild signs of dysautonomic dysfunction (nasal congestion, abnormal sweating, hypotension and fainting, excessive sleepiness, small hands and feet, and increased levels of prolactin, tiredness, and fatigue), more typical of AADC deficiency, were evaluated with new insight. Of the two AADC variants, the R347Q has already been characterized as a loss-of-function with severe catalytic impairments, while the novel L391P variant has been predicted to have a less severe impact. Bioinformatic analyses suggest that the amino acid substitution may affect affinity for the PLP coenzyme. Thus, the genotype corresponds to a phenotype with mild and late-onset symptoms, of which seizures were the clinical sign, leading to medical attention. This case report expands the spectrum of AADC deficiency phenotypes to encompass a less-disabling clinical condition including borderline cognitive functioning, drug-responsive epilepsy, and mild autonomic dysfunction.
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Affiliation(s)
- Ida Cursio
- Child Neurology and Psychiatric Unit, Pediatric Hospital G. Salesi, Azienda Ospedaliero Universitaria delle Marche, Ancona, Italy
| | - Sabrina Siliquini
- Child Neurology and Psychiatric Unit, Pediatric Hospital G. Salesi, Azienda Ospedaliero Universitaria delle Marche, Ancona, Italy
| | - Claudia Carducci
- Department of Experimental Medicine, Sapienza - Università di Roma, Rome, Italy
| | - Giovanni Bisello
- Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Mario Mastrangelo
- Department of Women/Child Health and Urological Science, Sapienza - Università di Roma, Rome, Italy
| | - Vincenzo Leuzzi
- Department of Human Neuroscience, Sapienza - Università di Roma, Rome, Italy
| | - Mariarita Bertoldi
- Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Carla Marini
- Child Neurology and Psychiatric Unit, Pediatric Hospital G. Salesi, Azienda Ospedaliero Universitaria delle Marche, Ancona, Italy
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Bisello G, Rossignoli G, Choi S, Phillips RS, Bertoldi M. Active site serine-193 modulates activity of human aromatic amino acid decarboxylase. Biochem Biophys Res Commun 2023; 679:6-14. [PMID: 37651872 DOI: 10.1016/j.bbrc.2023.08.049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 08/08/2023] [Accepted: 08/22/2023] [Indexed: 09/02/2023]
Abstract
Aromatic amino acid decarboxylase is a pyridoxal 5'-phosphate-dependent enzyme responsible for the synthesis of the neurotransmitters, dopamine and serotonin. Here, by a combination of bioinformatic predictions and analyses, phosphorylation assays, spectroscopic investigations and activity measurements, we determined that Ser-193, a conserved residue located at the active site, can be phosphorylated, increasing catalytic efficiency. In order to determine the molecular basis for this functional improvement, we determined the structural and kinetic properties of the site-directed variants S193A, S193D and S193E. While S193A retains 27% of the catalytic efficiency of wild-type, the two acidic side chain variants are impaired in catalysis with efficiencies of about 0.15% with respect to the wild-type. Thus, even if located at the active site, Ser-193 is not essential for enzyme activity. We advance the idea that this residue is fundamental for the correct architecture of the active site in terms of network of interactions triggering catalysis. This role has been compared with the properties of the Ser-194 of the highly homologous enzyme histidine decarboxylase whose catalytic loop is visible in the spatial structure, allowing us to propose the validation for the effect of the phosphorylation. The effect could be interesting for AADC deficiency, a rare monogenic disease, whose broad clinical phenotype could be also related to post translational AADC modifications.
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Affiliation(s)
- Giovanni Bisello
- Section of Biochemistry, Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Strada Le Grazie, 8, Verona, Italy
| | - Giada Rossignoli
- Section of Biochemistry, Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Strada Le Grazie, 8, Verona, Italy
| | - Sarah Choi
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Robert S Phillips
- Department of Chemistry, University of Georgia, Athens, GA, 30602, USA; Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA.
| | - Mariarita Bertoldi
- Section of Biochemistry, Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Strada Le Grazie, 8, Verona, Italy.
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Abukhaled M, Al Muqbil M, Alghamdi MA, Hundallah K, Suleiman J, Ben-Omran T, Alfadhel M, Almannai M, Alsaleh R, Tabarki B. Aromatic L-amino acid decarboxylase deficiency in countries in the Middle East: a case series and literature review. Eur J Pediatr 2023:10.1007/s00431-023-04886-5. [PMID: 36928758 PMCID: PMC10257624 DOI: 10.1007/s00431-023-04886-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 02/15/2023] [Accepted: 02/16/2023] [Indexed: 03/18/2023]
Abstract
Aromatic L-amino acid decarboxylase (AADC) deficiency is a rare inherited neurometabolic disorder that can lead to severe physical and developmental impairment. This report includes 16 patients from the Middle East and is the largest series of patients with confirmed AADC deficiency from this region reported to date. The patients displayed a range of signs and symptoms at presentation and almost all failed to reach major motor milestones. Missed and delayed diagnoses were common leading to the late introduction of targeted treatments. Eight unique variants were identified in the DDC gene, including six missense and two intronic variants. A previously undescribed variant was identified: an intronic variant between exons 13 and 14 (c.1243-10A>G). The patients were mostly treated with currently recommended medications, including dopamine agonists, vitamin B6, and monoamine oxidase inhibitors. One patient responded well, but treatment outcomes were otherwise mostly limited to mild symptomatic improvements. Five patients had died by the time of data collection, confirming that the condition is associated with premature mortality. There is an urgent need for earlier diagnosis, particularly given the potential for gene therapy as a transformative treatment for AADC deficiency when provided at an early age. Conclusions: Delays in the diagnosis of AADC deficiency are common. There is an urgent need for earlier diagnosis, particularly given the potential for gene therapy as a transformative treatment for AADC deficiency when provided at an early age. What is Known: • Aromatic L-amino acid decarboxylase deficiency is a rare neurometabolic disorder that can lead to severe physical and developmental impairment. • Currently recommended medications provide mostly mild symptomatic improvements. What is New: • The clinical presentation of sixteen patients with confirmed AADC deficiency varied considerably and almost all failed to reach major motor milestones. • There is an urgent need for earlier diagnosis, given the potential for gene therapy as a transformative treatment for AADC deficiency when provided at an early age.
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Affiliation(s)
- Musaad Abukhaled
- Department of Neurosciences, King Faisal Specialist Hospital and Research Center, (KFSH-RC), Riyadh, Saudi Arabia.
| | - Mohammed Al Muqbil
- College of Medicine, King Saud bin Abdulaziz University for Health Sciences (KSAU-HS), Riyadh, Saudi Arabia.,Division of Pediatric Neurology, Department of Pediatrics, King Abdullah Specialized Children's Hospital, National Guard Health Affairs (NGHA), Riyadh, Saudi Arabia.,King Abdullah International Medical Research Center, Ministry of National Guard Health Affairs (MNG-HA), Riyadh, Saudi Arabia
| | - Malak Ali Alghamdi
- Medical Genetic Division, Pediatric Department, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Khalid Hundallah
- Division of Neurology, Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Jehan Suleiman
- Division of Neurology, Department of Pediatrics, Tawam Hospital, Al Ain, United Arab Emirates.,College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates.,American Center for Psychiatry and Neurology, Abu Dhabi, United Arab Emirates
| | - Tawfeg Ben-Omran
- Sidra Medicine and Research Center, Doha, Qatar.,Hamad Medical Corporation, Doha, Qatar
| | - Majid Alfadhel
- Department of Genetics and Precision Medicine, Department of Pediatrics, King Saud bin Abdulaziz University for Health Sciences, King Abdulaziz Medical City, Riyadh, Saudi Arabia.,Medical Genomic Research Department, King Abdullah International Medical Research Centre (KAIMRC), King Saud bin Abdulaziz University for Health Sciences (KSAU-HS), Ministry of National Guard Health Affairs (MNG-HA), Riyadh, Saudi Arabia
| | - Mohammed Almannai
- Department of Genetics and Precision Medicine, Department of Pediatrics, King Saud bin Abdulaziz University for Health Sciences, King Abdulaziz Medical City, Riyadh, Saudi Arabia.,Medical Genomic Research Department, King Abdullah International Medical Research Centre (KAIMRC), King Saud bin Abdulaziz University for Health Sciences (KSAU-HS), Ministry of National Guard Health Affairs (MNG-HA), Riyadh, Saudi Arabia
| | | | - Brahim Tabarki
- Division of Neurology, Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
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Elucidating the Interaction between Pyridoxine 5'-Phosphate Oxidase and Dopa Decarboxylase: Activation of B6-Dependent Enzyme. Int J Mol Sci 2022; 24:ijms24010642. [PMID: 36614085 PMCID: PMC9820991 DOI: 10.3390/ijms24010642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 12/22/2022] [Accepted: 12/26/2022] [Indexed: 12/31/2022] Open
Abstract
Pyridoxal 5'-phosphate (PLP), the active form of vitamin B6, serves as a cofactor for scores of B6-dependent (PLP-dependent) enzymes involved in many cellular processes. One such B6 enzyme is dopa decarboxylase (DDC), which is required for the biosynthesis of key neurotransmitters, e.g., dopamine and serotonin. PLP-dependent enzymes are biosynthesized as apo-B6 enzymes and then converted to the catalytically active holo-B6 enzymes by Schiff base formation between the aldehyde of PLP and an active site lysine of the protein. In eukaryotes, PLP is made available to the B6 enzymes through the activity of the B6-salvage enzymes, pyridoxine 5'-phosphate oxidase (PNPO) and pyridoxal kinase (PLK). To minimize toxicity, the cell keeps the content of free PLP (unbound) very low through dephosphorylation and PLP feedback inhibition of PNPO and PLK. This has led to a proposed mechanism of complex formation between the B6-salvage enzymes and apo-B6 enzymes prior to the transfer of PLP, although such complexes are yet to be characterized at the atomic level, presumably due to their transient nature. A computational study, for the first time, was used to predict a likely PNPO and DDC complex, which suggested contact between the allosteric PLP tight-binding site on PNPO and the active site of DDC. Using isothermal calorimetry and/or surface plasmon resonance, we also show that PNPO binds both apoDDC and holoDDC with dissociation constants of 0.93 ± 0.07 μM and 2.59 ± 0.11 μM, respectively. Finally, in the presence of apoDDC, the tightly bound PLP on PNPO is transferred to apoDDC, resulting in the formation of about 35% holoDDC.
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Himmelreich N, Montioli R, Garbade SF, Kopesky J, Elsea SH, Carducci C, Voltattorni CB, Blau N. Spectrum of DDC variants causing aromatic l-amino acid decarboxylase (AADC) deficiency and pathogenicity interpretation using ACMG-AMP/ACGS recommendations. Mol Genet Metab 2022; 137:359-381. [PMID: 36427457 DOI: 10.1016/j.ymgme.2022.11.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 10/25/2022] [Accepted: 11/08/2022] [Indexed: 11/13/2022]
Abstract
Pathogenic variants in dopa decarboxylase (DDC), the gene encoding the aromatic l-amino acid decarboxylase (AADC) enzyme, lead to a severe deficiency of neurotransmitters, resulting in neurological, neuromuscular, and behavioral manifestations clinically characterized by developmental delays, oculogyric crises, dystonia, and severe neurologic dysfunction in infancy. Historically, therapy has been aimed at compensating for neurotransmitter abnormalities, but response to pharmacologic therapy varies, and in most cases, the therapy shows little or no benefit. A novel human DDC gene therapy was recently approved in the European Union that targets the underlying genetic cause of the disorder, providing a new treatment option for patients with AADC deficiency. However, the applicability of human DDC gene therapy depends on the ability of laboratories and clinicians to interpret the results of genetic testing accurately enough to diagnose the patient. An accurate interpretation of genetic variants depends in turn on expert-guided curation of locus-specific databases. The purpose of this research was to identify previously uncharacterized DDC variants that are of pathologic significance in AADC deficiency as well as characterize and curate variants of unknown significance (VUSs) to further advance the diagnostic accuracy of genetic testing for this condition. DDC variants were identified using existing databases and the literature. The pathogenicity of the variants was classified using modified American College of Medical Genetics and Genomics/Association for Molecular Pathology/Association for Clinical Genomic Science (ACMG-AMP/ACGS) criteria. To improve the current variant interpretation recommendations, in silico variant interpretation tools were combined with structural 3D modeling of protein variants and applied comparative analysis to predict the impact of the variant on protein function. A total of 422 variants were identified (http://biopku.org/home/pnddb.asp). Variants were identified on nearly all introns and exons of the DDC gene, as well as the 3' and 5' untranslated regions. The largest percentage of the identified variants (48%) were classified as missense variants. The molecular effects of these missense variants were then predicted, and the pathogenicity of each was classified using a number of variant effect predictors. Using ACMG-AMP/ACGS criteria, 7% of variants were classified as pathogenic, 32% as likely pathogenic, 58% as VUSs of varying subclassifications, 1% as likely benign, and 1% as benign. For 101 out of 108 reported genotypes, at least one allele was classified as pathogenic or likely pathogenic. In silico variant pathogenicity interpretation tools, combined with structural 3D modeling of variant proteins and applied comparative analysis, have improved the current DDC variant interpretation recommendations, particularly of VUSs.
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Affiliation(s)
- Nastassja Himmelreich
- Dietmar-Hopp Metabolic Center and Centre for Pediatrics and Adolescent Medicine, University Children's Hospital, Heidelberg, Germany
| | - Riccardo Montioli
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.
| | - Sven F Garbade
- Dietmar-Hopp Metabolic Center and Centre for Pediatrics and Adolescent Medicine, University Children's Hospital, Heidelberg, Germany.
| | - Jeffrey Kopesky
- Medical Affairs, PTC Therapeutics, Inc., South Plainfield, NJ, USA.
| | - Sarah H Elsea
- Department of Molecular & Human Genetics, Baylor College of Medicine, Houston, TX, USA.
| | - Carla Carducci
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy.
| | - Carla B Voltattorni
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.
| | - Nenad Blau
- Divisions of Metabolism, University Children's Hospital, Zürich, Switzerland.
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Compound Heterozygosis in AADC Deficiency and Its Complex Phenotype in Terms of AADC Protein Population. Int J Mol Sci 2022; 23:ijms231911238. [PMID: 36232540 PMCID: PMC9570296 DOI: 10.3390/ijms231911238] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 09/21/2022] [Accepted: 09/22/2022] [Indexed: 11/16/2022] Open
Abstract
Aromatic amino acid decarboxylase (AADC) deficiency is a rare monogenic disease due to mutations in the ddc gene producing AADC, a homodimeric pyridoxal 5′-phosphate-dependent enzyme. The disorder is often fatal in the first decade and is characterized by profound motor impairments and developmental delay. In the last two years, there has been a net rise in the number of patients and variants identified, maybe also pushed by the ongoing gene therapy trials. The majority of the identified genotypes are compound heterozygous (about 70%). Efforts are underway to reach early diagnosis, find possible new markers/new fast methods, and predict clinical outcome. However, no clear correlation of genotype-to-phenotype exists to date. Nevertheless, for homozygous patients, reliable results have been obtained using genetic methods combined with available computational tools on crystal structures corroborated by biochemical investigations on recombinant homodimeric AADC variants that have been obtained and characterized in solution. For these variants, the molecular basis for the defect has been suggested and validated, since it correlates quite well with mildness/severity of the homozygous phenotype. Instead, prediction for compound heterozygous patients is more difficult since complementation effects could happen. Here, by analyzing the existing literature on compound heterozygosity in AADC deficiency and other genetic disorders, we highlight that, in order to assess pathogenicity, the measurement of activity of the AADC heterodimeric variant should be integrated by bioinformatic, structural, and functional data on the whole protein constellation theoretically present in such patients. A wider discussion on symptomatic heterozygosity in AADC deficiency is also presented.
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Wang H, Li J, Zhou J, Dai L, Ding C, Li M, Feng W, Fang F, Ren X, Wang X. Oculogyric crisis mimicked epilepsy in a Chinese aromatic L-amino acid decarboxylase-deficiency patient: A case report. Front Neurol 2022; 13:919583. [PMID: 36119679 PMCID: PMC9481412 DOI: 10.3389/fneur.2022.919583] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 07/20/2022] [Indexed: 11/13/2022] Open
Abstract
BackgroundAromatic amino acid decarboxylase (AADC) deficiency is a rare, autosomal recessive neurometabolic disorder with heterogeneous phenotype, including hypotonia, movement disorders, autonomic dysfunction, and developmental delay. Here, we reported a Chinese patient with AADCD who was initially misdiagnosed with epilepsy.Case presentationThe proband was a 4-month-old Chinese girl, representing hypotonia, episodes of oculogyric crises with dystonia, and delayed developmental milestones. The patient was first misdiagnosed with epilepsy because of the similarity between episodes of oculogyric crisis and epileptic seizure. The accurate diagnosis of AADCD was established through analysis of neurotransmitters in cerebrospinal fluid (CSF). The genetic test confirmed the patient carried novel compound heterozygous mutations in the DDC gene:c.419G>A and c.1375C>T.ConclusionThis study reported a patient with AADCD who was initially misdiagnosed as epilepsy. Two novel missense mutations in the DDC gene were identified from the patient and her family. Little infants with epileptic-like attacks should consider AADCD. An accurate diagnosis of AADCD is essential for drug choice and patient management.
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Affiliation(s)
- Hongmei Wang
- Department of Neurology, National Center for Children's Health, Beijing Children's Hospital, Capital Medical University, Beijing, China
| | - Jiahong Li
- Department of Gastroenterology, National Center for Children's Health, Beijing Children's Hospital, Capital Medical University, Beijing, China
| | - Ji Zhou
- Department of Neurology, National Center for Children's Health, Beijing Children's Hospital, Capital Medical University, Beijing, China
| | - Lifang Dai
- Department of Neurology, National Center for Children's Health, Beijing Children's Hospital, Capital Medical University, Beijing, China
| | - Changhong Ding
- Department of Neurology, National Center for Children's Health, Beijing Children's Hospital, Capital Medical University, Beijing, China
| | - Mo Li
- Department of Neurology, National Center for Children's Health, Beijing Children's Hospital, Capital Medical University, Beijing, China
| | - Weixing Feng
- Department of Neurology, National Center for Children's Health, Beijing Children's Hospital, Capital Medical University, Beijing, China
| | - Fang Fang
- Department of Neurology, National Center for Children's Health, Beijing Children's Hospital, Capital Medical University, Beijing, China
| | - Xiaotun Ren
- Department of Neurology, National Center for Children's Health, Beijing Children's Hospital, Capital Medical University, Beijing, China
| | - Xiaohui Wang
- Department of Neurology, National Center for Children's Health, Beijing Children's Hospital, Capital Medical University, Beijing, China
- *Correspondence: Xiaohui Wang
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10
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Bisello G, Kusmierska K, Verbeek MM, Sykut-Cegielska J, Willemsen MAAP, Wevers RA, Szymańska K, Poznanski J, Drozak J, Wertheim-Tysarowska K, Rygiel AM, Bertoldi M. The novel P330L pathogenic variant of aromatic amino acid decarboxylase maps on the catalytic flexible loop underlying its crucial role. Cell Mol Life Sci 2022; 79:305. [PMID: 35593933 PMCID: PMC9121088 DOI: 10.1007/s00018-022-04343-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 04/13/2022] [Accepted: 05/01/2022] [Indexed: 12/14/2022]
Abstract
Aromatic amino acid decarboxylase (AADC) deficiency is a rare monogenic disease, often fatal in the first decade, causing severe intellectual disability, movement disorders and autonomic dysfunction. It is due to mutations in the gene coding for the AADC enzyme responsible for the synthesis of dopamine and serotonin. Using whole exome sequencing, we have identified a novel homozygous c.989C > T (p.Pro330Leu) variant of AADC causing AADC deficiency. Pro330 is part of an essential structural and functional element: the flexible catalytic loop suggested to cover the active site as a lid and properly position the catalytic residues. Our investigations provide evidence that Pro330 concurs in the achievement of an optimal catalytic competence. Through a combination of bioinformatic approaches, dynamic light scattering measurements, limited proteolysis experiments, spectroscopic and in solution analyses, we demonstrate that the substitution of Pro330 with Leu, although not determining gross conformational changes, results in an enzymatic species that is highly affected in catalysis with a decarboxylase catalytic efficiency decreased by 674- and 194-fold for the two aromatic substrates. This defect does not lead to active site structural disassembling, nor to the inability to bind the pyridoxal 5’-phosphate (PLP) cofactor. The molecular basis for the pathogenic effect of this variant is rather due to a mispositioning of the catalytically competent external aldimine intermediate, as corroborated by spectroscopic analyses and pH dependence of the kinetic parameters. Altogether, we determined the structural basis for the severity of the manifestation of AADC deficiency in this patient and discussed the rationale for a precision therapy.
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Affiliation(s)
- Giovanni Bisello
- Department of Neuroscience, Biomedicine and Movement Sciences, Section of Biochemistry, University of Verona, Strada Le Grazie 8, 37134, Verona, Italy
| | - Katarzyna Kusmierska
- Department of Screening and Metabolic Diagnostics, Institute of Mother and Child, Warsaw, Poland
| | - Marcel M Verbeek
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Geert Grooteplein 10, 6525 GA, Nijmegen, The Netherlands
- Translational Metabolic Laboratory, Department Laboratory Medicine, Radboud University Medical Cente, Geert Grooteplein 10, 6525 GA, Nijmegen, The Netherlands
| | - Jolanta Sykut-Cegielska
- Department of Inborn Errors of Metabolism and Paediatrics, Institute of Mother and Child, Warsaw, Poland
| | - Michèl A A P Willemsen
- Department of Pediatric Neurology, Radboud University Medical Centre, Geert Grooteplein 10, 6525 GA, Nijmegen, The Netherlands
| | - Ron A Wevers
- Translational Metabolic Laboratory, Department Laboratory Medicine, Radboud University Medical Cente, Geert Grooteplein 10, 6525 GA, Nijmegen, The Netherlands
| | - Krystyna Szymańska
- Department of Child and Adolescent Psychiatry, Medical University of Warsaw, Warsaw, Poland
| | - Jarosław Poznanski
- Department of Biophysics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Jakub Drozak
- Department of Metabolic Regulation, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | | | | | - Mariarita Bertoldi
- Department of Neuroscience, Biomedicine and Movement Sciences, Section of Biochemistry, University of Verona, Strada Le Grazie 8, 37134, Verona, Italy.
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11
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Saleh DA, Attia AAEM. Shedding light on the phenotypic–genotypic correlation of rare treatable and potentially treatable pediatric movement disorders. EGYPTIAN JOURNAL OF MEDICAL HUMAN GENETICS 2022. [DOI: 10.1186/s43042-022-00286-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Advances in genetic science have led to the identification of many rare treatable pediatric movements disorders (MDs). We explored the phenotypic–genotypic spectrum of pediatric patients presenting with MDs. By this, we aimed at raising awareness about such rare disorders, especially in our region. Over the past 3 years, we reviewed the demographic data, clinical profile, molecular genetics and other diagnostic workups of pediatric patients presenting with MDs.
Results
Twelve patients were identified; however, only six patients were genetically confirmed. The phenomenology of MDs ranged from paroxysmal kinesigenic choreoathetosis (1 patient), exercise-induced dyskinesia (2 patients), ataxia (2 patients) and dystonia (2 patients). Whole-exome sequencing in addition to the functional studies for some patients revealed a specific genetic diagnosis being responsible for their MDs. The genetic diagnosis of our patients included infantile convulsions and paroxysmal choreoathetosis syndrome and episodic ataxia due to “pathogenic homozygous mutation of PRRT2 gene,” glucose transporter type 1 deficiency-exercise induced dyskinesia due to “De Novo pathogenic heterozygous missense mutation of exon 4 of SLC2A1 gene,” aromatic L amino acid decarboxylase deficiency due to “pathogenic homozygous mutation of the DDC gene,” myopathy with extrapyramidal signs due to “likely pathogenic homozygous mutations of the MICU1 gene,” mitochondrial trifunctional protein deficiency due to “homozygous variant of uncertain significance (VUS) of HADHB gene” and glutaric aciduria II with serine deficiency due to “homozygous VUS for both ETFDH and PHGDH genes.” After receiving the treatment as per recognized treatment protocols, two patients showed complete resolution of symptoms and the rest showed variable responses.
Conclusion
Identifying the genetic etiology of our patients guided us to provide either disease-specific treatment or redirected our management plan. Hence, highlighting the value of molecular genetic analysis to avoid the diagnostic odyssey and identify treatable MDs.
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12
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Abukhaled M, Alrakaf L, Aldhalaan H, Al Yamani S. Case report: Aromatic L-amino acid decarboxylase deficiency in three patient cases from the Kingdom of Saudi Arabia. Front Pediatr 2022; 10:1016239. [PMID: 36727005 PMCID: PMC9885213 DOI: 10.3389/fped.2022.1016239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 10/17/2022] [Indexed: 01/19/2023] Open
Abstract
Aromatic L-amino acid decarboxylase (AADC) deficiency is an ultra-rare and often severe neurometabolic disorder resulting from variants in the dopa decarboxylase (DDC) gene. A timely diagnosis is critical to prevent secondary complications, promote development, and optimize outcomes from future innovative treatment options, such as gene therapy. This article describes three patients with AADC deficiency managed in the Kingdom of Saudi Arabia (KSA). All three patients had homozygous variants within the DDC gene, including one novel gene variant (c.245G > A, p.Arg82Glu), and presented with symptoms from birth. In all cases, a diagnostic delay was observed owing to non-specific signs and symptoms, a lack of disease awareness among primary care physicians, and delays associated with outsourcing of genetic tests. All three patients were managed by a multidisciplinary team at a specialist tertiary center. Clinical outcomes for all three cases were poor, with one patient passing away at 3 years of age and the other two patients continuing to experience substantial disability and poor quality of life. There is an urgent need to raise awareness and improve diagnostic testing for rare diseases such as AADC deficiency in the KSA in order to improve outcomes, particularly as innovative disease-targeting therapies become available.
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Affiliation(s)
- Musaad Abukhaled
- Department of Neurosciences, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Laila Alrakaf
- Department of Neurosciences, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Hesham Aldhalaan
- Department of Neurosciences, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Suad Al Yamani
- Department of Neurosciences, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
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13
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Hasegawa Y, Nishi E, Mishima Y, Sakaguchi T, Sekiguchi F, Miyake N, Kojima K, Osaka H, Matsumoto N, Okamoto N. Novel variants in aromatic L-amino acid decarboxylase deficiency: Case report of sisters with mild phenotype. Brain Dev 2021; 43:1023-1028. [PMID: 34481663 DOI: 10.1016/j.braindev.2021.07.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 07/01/2021] [Accepted: 07/13/2021] [Indexed: 10/20/2022]
Abstract
BACKGROUND Aromatic L-amino acid decarboxylase (AADC) deficiency, caused by a pathogenic variant in the dopa decarboxylase (DDC) gene, is a rare neurometabolic disorder in which catecholamine and serotonin are not synthesized. From a large number of reports, it has been recognized that most affected patients show severe developmental delay in a bedridden state and are unable to speak. On the other hand, patients with a mild phenotype with AADC deficiency have been reported, but they number only a few cases. Therefore, the variation of phenotypes of the disease appears to be broad, and it may be challenging to diagnose an atypical phenotype as AADC deficiency. CASE REPORT We report novel compound heterozygous variants in DDC (c.202G > A and c.254C > T) in two sisters, whose main complaint was mild developmental delay, by whole-exome sequencing (WES). Additionally, we describe their clinical features and provide an image that shows the variants located at different sites responsible for the catalysis of AADC in a three-dimensional structure. The patients were prescribed a Monoamine oxidase (MAO) inhibitor after diagnosis. INTERPRETATION Our cases indicate that a comprehensive genomic approach helps to diagnose AADC deficiency with atypical features, and underscore the significance of understanding the variations of this disorder for diagnosis and appropriate treatment.
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Affiliation(s)
- Yuiko Hasegawa
- Department of Medical Genetics, Osaka Women's and Children's Hospital, Izumi, Japan.
| | - Eriko Nishi
- Department of Medical Genetics, Osaka Women's and Children's Hospital, Izumi, Japan
| | - Yuko Mishima
- Department of Medical Genetics, Osaka Women's and Children's Hospital, Izumi, Japan
| | - Tomohiro Sakaguchi
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Futoshi Sekiguchi
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Noriko Miyake
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Karin Kojima
- Department of Pediatrics, Jichi Medical University, Tochigi, Japan
| | - Hitoshi Osaka
- Department of Pediatrics, Jichi Medical University, Tochigi, Japan
| | - Naomichi Matsumoto
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Nobuhiko Okamoto
- Department of Medical Genetics, Osaka Women's and Children's Hospital, Izumi, Japan
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14
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Rossignoli G, Krämer K, Lugarà E, Alrashidi H, Pope S, De La Fuente Barrigon C, Barwick K, Bisello G, Ng J, Counsell J, Lignani G, Heales SJR, Bertoldi M, Barral S, Kurian MA. Aromatic l-amino acid decarboxylase deficiency: a patient-derived neuronal model for precision therapies. Brain 2021; 144:2443-2456. [PMID: 33734312 PMCID: PMC8418346 DOI: 10.1093/brain/awab123] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 01/25/2021] [Accepted: 02/08/2021] [Indexed: 11/13/2022] Open
Abstract
Aromatic l-amino acid decarboxylase (AADC) deficiency is a complex inherited neurological disorder of monoamine synthesis which results in dopamine and serotonin deficiency. The majority of affected individuals have variable, though often severe cognitive and motor delay, with a complex movement disorder and high risk of premature mortality. For most, standard pharmacological treatment provides only limited clinical benefit. Promising gene therapy approaches are emerging, though may not be either suitable or easily accessible for all patients. To characterize the underlying disease pathophysiology and guide precision therapies, we generated a patient-derived midbrain dopaminergic neuronal model of AADC deficiency from induced pluripotent stem cells. The neuronal model recapitulates key disease features, including absent AADC enzyme activity and dysregulated dopamine metabolism. We observed developmental defects affecting synaptic maturation and neuronal electrical properties, which were improved by lentiviral gene therapy. Bioinformatic and biochemical analyses on recombinant AADC predicted that the activity of one variant could be improved by l-3,4-dihydroxyphenylalanine (l-DOPA) administration; this hypothesis was corroborated in the patient-derived neuronal model, where l-DOPA treatment leads to amelioration of dopamine metabolites. Our study has shown that patient-derived disease modelling provides further insight into the neurodevelopmental sequelae of AADC deficiency, as well as a robust platform to investigate and develop personalized therapeutic approaches.
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Affiliation(s)
- Giada Rossignoli
- Developmental Neurosciences, GOS Institute of Child Health, University College London, London WC1N 1EH, UK
- Biological Chemistry, NBM Department, University of Verona, 37134 Verona, Italy
| | - Karolin Krämer
- Developmental Neurosciences, GOS Institute of Child Health, University College London, London WC1N 1EH, UK
| | - Eleonora Lugarà
- Clinical and Experimental Epilepsy, Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
| | - Haya Alrashidi
- Genetics and Genomic Medicine, GOS Institute of Child Health, University College London, London WC1N 1EH, UK
| | - Simon Pope
- Neurometabolic Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | | | - Katy Barwick
- Developmental Neurosciences, GOS Institute of Child Health, University College London, London WC1N 1EH, UK
| | - Giovanni Bisello
- Biological Chemistry, NBM Department, University of Verona, 37134 Verona, Italy
| | - Joanne Ng
- Developmental Neurosciences, GOS Institute of Child Health, University College London, London WC1N 1EH, UK
- Gene Transfer Technology Group, EGA-Institute for Women's Health, University College London, London WC1E 6HU, UK
| | - John Counsell
- Developmental Neurosciences, GOS Institute of Child Health, University College London, London WC1N 1EH, UK
| | - Gabriele Lignani
- Clinical and Experimental Epilepsy, Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
| | - Simon J R Heales
- Neurometabolic Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
- Centre for Inborn Errors of Metabolism, GOS Institute of Child Health, UniversCity College London, London WC1N 1EH, UK
| | - Mariarita Bertoldi
- Biological Chemistry, NBM Department, University of Verona, 37134 Verona, Italy
- Correspondence may also be addressed to: Prof Mariarita Bertoldi Department of Neuroscience, Biomedicine and Movement Sciences Biological Chemistry Section, Room 1.24 Strada le Grazie 8, 37134 Verona, Italy E-mail:
| | - Serena Barral
- Developmental Neurosciences, GOS Institute of Child Health, University College London, London WC1N 1EH, UK
| | - Manju A Kurian
- Developmental Neurosciences, GOS Institute of Child Health, University College London, London WC1N 1EH, UK
- Department of Neurology, Great Ormond Street Hospital, London WC1N 3JH, UK
- Correspondence to: Prof Manju Kurian Zayed Centre for Research UCL Great Ormond Street Institute of Child Health 20 Guilford St, London WC1N 1DZ, UK E-mail:
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15
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Longo C, Montioli R, Bisello G, Palazzi L, Mastrangelo M, Brennenstuhl H, de Laureto PP, Opladen T, Leuzzi V, Bertoldi M. Compound heterozygosis in AADC deficiency: A complex phenotype dissected through comparison among heterodimeric and homodimeric AADC proteins. Mol Genet Metab 2021; 134:147-155. [PMID: 34479793 DOI: 10.1016/j.ymgme.2021.08.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 08/25/2021] [Accepted: 08/25/2021] [Indexed: 10/20/2022]
Abstract
Compound heterozygosis is the most diffuse and hardly to tackle condition in aromatic amino acid decarboxylase (AADC) deficiency, a genetic disease leading to severe neurological impairment. Here, by using an appropriate vector, we succeeded in obtaining high yields of AADC protein and characterizing two new heterodimers, T69M/S147R and C281W/M362T, detected in two AADC deficiency patients. We performed an extensive biochemical characterization of the heterodimeric recombinant proteins and of the related homodimers, by a combination of dichroic and fluorescence spectroscopy and activity assays together with bioinformatic analyses. We found that T69M/S147R exhibits negative complementation in terms of activity but it is more stable than the average of the homodimeric counterparts. The heterodimer C281W/M362T retains a nearly good catalytic efficiency, whereas M362T homodimer is less affected and C281W homodimer is recovered as insoluble. These results, which are consistent with the related phenotypes, and the data emerging from previous studies, suggest that the severity of AADC deficiency is not directly explained by positive or negative complementation phenomena, but rather depends on: i) the integrity of one or both active sites; ii) the structural and functional properties of the entire pool of AADC proteins expressed. Overall, this integrated and cross-sectional approach enables proper characterization and depicts the functional result of subunit interactions in the dimeric structure and will help to elucidate the physio-pathological mechanisms in AADC deficiency.
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Affiliation(s)
- Carmen Longo
- Department of Neuroscience, Biomedicine and Movement Sciences, Section of Biological Chemistry, Strada Le Grazie 8, 37134 Verona, Italy
| | - Riccardo Montioli
- Department of Neuroscience, Biomedicine and Movement Sciences, Section of Biological Chemistry, Strada Le Grazie 8, 37134 Verona, Italy
| | - Giovanni Bisello
- Department of Neuroscience, Biomedicine and Movement Sciences, Section of Biological Chemistry, Strada Le Grazie 8, 37134 Verona, Italy
| | - Luana Palazzi
- Department of Pharmaceutical and Pharmacological Sciences, CRIBI Biotechnology Center, University of Padua, Padua, Italy
| | - Mario Mastrangelo
- Unit of Child Neurology and Psychiatry Unit, Department of Human Neuroscience, Sapienza University of Rome, Italy
| | - Heiko Brennenstuhl
- University Children's Hospital Heidelberg, Department of General Pediatrics, Division of Neuropediatrics and Metabolic Medicine, Heidelberg, Germany
| | - Patrizia Polverino de Laureto
- Department of Pharmaceutical and Pharmacological Sciences, CRIBI Biotechnology Center, University of Padua, Padua, Italy
| | - Thomas Opladen
- University Children's Hospital Heidelberg, Department of General Pediatrics, Division of Neuropediatrics and Metabolic Medicine, Heidelberg, Germany
| | - Vincenzo Leuzzi
- Unit of Child Neurology and Psychiatry Unit, Department of Human Neuroscience, Sapienza University of Rome, Italy
| | - Mariarita Bertoldi
- Department of Neuroscience, Biomedicine and Movement Sciences, Section of Biological Chemistry, Strada Le Grazie 8, 37134 Verona, Italy.
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16
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Kubaski F, Herbst ZM, Pereira DA, Silva C, Chen C, Hwu PW, van der Linden H, Lourenço CM, Giugliani R. Evaluation of 3- O-methyldopa as a biomarker for aromatic L-amino acid decarboxylase deficiency in 7 Brazilian cases. Mol Genet Metab Rep 2021; 27:100744. [PMID: 33763332 PMCID: PMC7973244 DOI: 10.1016/j.ymgmr.2021.100744] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 03/04/2021] [Indexed: 12/05/2022] Open
Abstract
Aromatic L-amino acid decarboxylase (AADCD) deficiency is an autosomal recessive neurometabolic disorder, caused by biallelic mutations in the DDC gene, that impairs the synthesis or metabolism of neurotransmitters leading to severe motor dysfunction. The main clinical signs are oculogyric crisis, hypotonia, hypokinesia, and dystonia. The biochemical diagnosis can be performed in cerebrospinal fluid by neurotransmitter analysis, which requires an invasive lumbar puncture, and the sample needs to be shipped frozen to a reference laboratory, usually across a country border. Measurement of AADC activity in plasma is also possible, but available in a few labs globally. 3-O-methyldopa (3-OMD) is a catabolic product of L-dopa and it is elevated in patients with AADC deficiency. The quantification of 3-OMD can be performed in dried blood spots (DBS), a sample that could be shipped at room temperature. 3-OMD levels of AADCD patients and controls were quantified in DBS by liquid chromatography tandem mass spectrometry. DBS samples from 7 Brazilian patients previously diagnosed with AADCD were used to validate the 3-OMD quantification as a screening procedure for this condition. All AADCD patients had at least a four-fold increase of 3-OMD. Thus, 3-OMD seems to be a reliable marker for AADCD, with potential use also in the newborn screening of this disease.
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Affiliation(s)
- Francyne Kubaski
- PPGBM, UFRGS, Porto Alegre, Brazil
- Medical Genetics Service, HCPA, Porto Alegre, Brazil
- INAGEMP, Porto Alegre, Brazil
- Biodiscovery Research Group, HCPA, Porto Alegre, Brazil
- DRBrasil Research Group, HCPA, Porto Alegre, Brazil
| | | | | | - Camilo Silva
- Waters Technologies do Brasil Ltda, São Paulo, Brazil
| | | | | | | | | | - Roberto Giugliani
- PPGBM, UFRGS, Porto Alegre, Brazil
- Medical Genetics Service, HCPA, Porto Alegre, Brazil
- INAGEMP, Porto Alegre, Brazil
- Biodiscovery Research Group, HCPA, Porto Alegre, Brazil
- DRBrasil Research Group, HCPA, Porto Alegre, Brazil
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17
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Burlina A, Giuliani A, Polo G, Gueraldi D, Gragnaniello V, Cazzorla C, Opladen T, Hoffmann G, Blau N, Burlina AP. Detection of 3-O-methyldopa in dried blood spots for neonatal diagnosis of aromatic L-amino-acid decarboxylase deficiency: The northeastern Italian experience. Mol Genet Metab 2021; 133:56-62. [PMID: 33744095 DOI: 10.1016/j.ymgme.2021.03.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 03/08/2021] [Accepted: 03/09/2021] [Indexed: 11/23/2022]
Abstract
OBJECTIVE Aromatic L-amino acid decarboxylase (AADC) deficiency is a rare inherited autosomal recessive disorder of biogenic amine metabolism. Diagnosis requires analysis of neurotransmitter metabolites in cerebrospinal fluid, AADC enzyme activity analysis, or molecular analysis of the DDC gene. 3-O-methyldopa (3-OMD) is a key screening biomarker for AADC deficiency. METHODS We describe a rapid method for 3-OMD determination in dried blood spots (DBS) using flow-injection analysis tandem mass spectrometry with NeoBase™ 2 reagents and 13C6-tyrosine as an internal standard, which are routinely used in high-throughput newborn screening. We assessed variability using quality control samples over a range of 3-OMD concentrations. RESULTS Within-day and between-day precision determined with quality control samples demonstrated coefficients of variation <15%. 3-OMD concentrations in 1000 healthy newborns revealed a mean of 1.33 μmol/L (SD ± 0.56, range 0.61-3.05 μmol/L), 100 non-AADC control subjects (age 7 days - 1 year) showed a mean of 1.19 μmol/L (SD ± 0.35-2.00 μmol/L), and 81 patients receiving oral L-Dopa had a mean 3-OMD concentration of 14.90 μmol/L (SD ± 14.18, range 0.4-80.3 μmol/L). A patient with confirmed AADC was retrospectively analyzed and correctly identified (3-OMD 10.51 μmol/L). In April 2020, we started a pilot project for identifying AADC deficiency in DBSs routinely submitted to the expanded newborn screening program. 3-OMD concentrations were measured in 21,867 samples; no patients with AADC deficiency were identified. One newborn had a high 3-OMD concentration due to maternal L-Dopa treatment. DISCUSSION We demonstrated a rapid new method to identify AADC deficiency using reagents and equipment already widely used in newborn screening programs. Although our study is limited, introduction of our method in expanded neonatal screening is feasible and could facilitate deployment of screening, allowing for early diagnosis that is important for effective treatment.
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Affiliation(s)
- Alberto Burlina
- Division of Inherited Metabolic Diseases, Department of Diagnostic Services, University Hospital, Padua, Italy.
| | - Antonella Giuliani
- Division of Inherited Metabolic Diseases, Department of Diagnostic Services, University Hospital, Padua, Italy
| | - Giulia Polo
- Division of Inherited Metabolic Diseases, Department of Diagnostic Services, University Hospital, Padua, Italy
| | - Daniela Gueraldi
- Division of Inherited Metabolic Diseases, Department of Diagnostic Services, University Hospital, Padua, Italy
| | - Vincenza Gragnaniello
- Division of Inherited Metabolic Diseases, Department of Diagnostic Services, University Hospital, Padua, Italy
| | - Chiara Cazzorla
- Division of Inherited Metabolic Diseases, Department of Diagnostic Services, University Hospital, Padua, Italy
| | - Thomas Opladen
- Department of Pediatrics, University of Heidelberg, Germany
| | - Georg Hoffmann
- Department of Pediatrics, University of Heidelberg, Germany
| | - Nenad Blau
- Division of Metabolism, University Children's Hospital, Zürich, Switzerland
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18
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Aromatic Amino Acid Decarboxylase Deficiency: The Added Value of Biochemistry. Int J Mol Sci 2021; 22:ijms22063146. [PMID: 33808712 PMCID: PMC8003434 DOI: 10.3390/ijms22063146] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 03/15/2021] [Accepted: 03/16/2021] [Indexed: 11/30/2022] Open
Abstract
Aromatic amino acid decarboxylase (AADC) deficiency is a rare, autosomal recessive neurometabolic disorder caused by mutations in the DDC gene, leading to a deficit of AADC, a pyridoxal 5′-phosphate requiring enzyme that catalyzes the decarboxylation of L-Dopa and L-5-hydroxytryptophan in dopamine and serotonin, respectively. Although clinical and genetic studies have given the major contribution to the diagnosis and therapy of AADC deficiency, biochemical investigations have also helped the comprehension of this disorder at a molecular level. Here, we reported the steps leading to the elucidation of the functional and structural features of the enzyme that were useful to identify the different molecular defects caused by the mutations, either in homozygosis or in heterozygosis, associated with AADC deficiency. By revisiting the biochemical data available on the characterization of the pathogenic variants in the purified recombinant form, and interpreting them on the basis of the structure-function relationship of AADC, it was possible: (i) to define the enzymatic phenotype of patients harboring pathogenic mutations and at the same time to propose specific therapeutic managements, and (ii) to identify residues and/or regions of the enzyme relevant for catalysis and/or folding of AADC.
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19
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Wen Y, Wang J, Zhang Q, Chen Y, Bao X. The genetic and clinical characteristics of aromatic L-amino acid decarboxylase deficiency in mainland China. J Hum Genet 2020; 65:759-769. [PMID: 32409695 DOI: 10.1038/s10038-020-0770-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 04/12/2020] [Accepted: 04/26/2020] [Indexed: 11/10/2022]
Abstract
Aromatic L-amino acid decarboxylase deficiency (AADCD) is a rare neurotransmitter metabolic disorder caused by DDC gene mutations, which leads to the metabolic disturbance of dopamine and serotonin. Most of the reported cases came from Taiwan China, but patients from mainland China were seldomly reported. The current study was the largest AADCD patient cohort from mainland China. Twenty-three patients with clinical features of AADCD and DDC gene variants were recruited. A total of 16 DDC variants were identified in this study, of which four variants (c.2T>C, c.277A>G, c.1021+1G>A, c.565G>T) were never reported previously. The intronic variant c.714+4A>T was the most common one, with an allele frequency of 45.7%. And patients carried this intronic variant presented with severe clinical manifestations, all of whom were bedridden. In this study, the average onset age was 3.61 ± 1.28 months and the average age of diagnosis was 12.91 ± 5.62 months. Early onset hypotonia, oculogyric crises, and autonomic symptoms such as excessive sweating, nasal congestion and profuse nasal, and oropharyngeal secretions, were common in our patients. Eighteen patients (78.3%) got various degree of improvement after using pyridoxine monotherapy or different combination of pyridoxine, dopamine agonists, and monoamine oxidase (MAO) inhibitors.
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Affiliation(s)
- Yongxin Wen
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Jiaping Wang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Qingping Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Yan Chen
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Xinhua Bao
- Department of Pediatrics, Peking University First Hospital, Beijing, China.
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20
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Dai W, Lu D, Gu X, Yu Y. Aromatic L-amino acid decarboxylase deficiency in 17 Mainland China patients: Clinical phenotype, molecular spectrum, and therapy overview. Mol Genet Genomic Med 2020; 8:e1143. [PMID: 31975548 PMCID: PMC7057092 DOI: 10.1002/mgg3.1143] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 12/16/2019] [Indexed: 12/12/2022] Open
Abstract
Background Aromatic L‐amino acid decarboxylase deficiency (AADCD) is a rare, autosomal recessive inherited disorder which is characterized by neurological and vegetative symptoms. To date, only 130 patients with AADCD have been reported worldwide. Methods We demonstrated 14 previously undescribed patients together with three reportedly patients in Mainland China. Full clinical information was collected, and disease‐causing variants in the DDC gene were detected. Results The common clinical manifestation of patients, including intermittent oculogyric crises, retarded movement development, and autonomic symptoms. Notably, a patient showed bone‐density loss which have not been reported and two mildly phenotype patients improved psychomotor function after being prescribed medication. The most common genotype of Mainland Chinese AADCD is the splice‐site variant (IVS6+4A> T; c.714+4A> T), which accounts for 58.8%, followed by c.1234C>T variant. Three novel compound heterozygous variants, c. 565G>T, c.170T>C, and c.1021+1G>A, were firstly reported. It is important to recognize the milder phenotypes of the disease as these patients might respond well to therapy. Besides, we discovered that patients may presented with milder if found to be compound heterozygote or homozygote for one of the following variants c.478C>G, c.853C>T, c.1123C>T, c.387G>A, and c.665T>C. Discussion The clinical data of the cohort of 17 patients in Mainland China broaden the clinical, molecular, and treatment spectrum of aromatic L‐amino acid decarboxylase deficiency.
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Affiliation(s)
- Weiqian Dai
- Department of Pediatric Endocrinology and Genetic Metabolism, Shanghai Institute for Pediatric Research, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Deyun Lu
- Department of Pediatric Endocrinology and Genetic Metabolism, Shanghai Institute for Pediatric Research, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Xuefan Gu
- Department of Pediatric Endocrinology and Genetic Metabolism, Shanghai Institute for Pediatric Research, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yongguo Yu
- Department of Pediatric Endocrinology and Genetic Metabolism, Shanghai Institute for Pediatric Research, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
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21
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Montioli R, Bisello G, Dindo M, Rossignoli G, Voltattorni CB, Bertoldi M. New variants of AADC deficiency expand the knowledge of enzymatic phenotypes. Arch Biochem Biophys 2020; 682:108263. [PMID: 31953134 DOI: 10.1016/j.abb.2020.108263] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 01/05/2020] [Accepted: 01/08/2020] [Indexed: 02/06/2023]
Abstract
AADC deficiency is a rare genetic disease caused by mutations in the gene of aromatic amino acid decarboxylase, the pyridoxal 5'-phosphate dependent enzyme responsible for the synthesis of dopamine and serotonin. Here, following a biochemical approach together with an in silico bioinformatic analysis, we present a structural and functional characterization of 13 new variants of AADC. The amino acid substitutions are spread over the entire protein from the N-terminal (V60A), to its loop1 (H70Y and F77L), to the large domain (G96R) and its various motifs, i.e. loop2 (A110E), or a core β-barrel either on the surface (P210L, F251S and E283A) or in a more hydrophobic milieu (L222P, F237S and W267R) or loop3 (L353P), and to the C-terminal domain (R453C). Results show that the β-barrel variants exhibit a low solubility and those belonging to the surface tend to aggregate in their apo form, leading to the identification of a new enzymatic phenotype for AADC deficiency. Moreover, five variants of residues belonging to the large interface of AADC (V60A, G96R, A110E, L353P and R453C) are characterized by a decreased catalytic efficiency. The remaining ones (H70Y and F77L) present features typical of apo-to-holo impaired transition. Thus, defects in catalysis or in the acquirement of the correct holo structure are due not only to specific local domain effects but also to long-range effects at either the protein surface or the subunit interface. Altogether, the new characterized enzymatic phenotypes represent a further step in the elucidation of the molecular basis for the disease.
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Affiliation(s)
- Riccardo Montioli
- Department of Neuroscience, Biomedicine and Movement Sciences, Section of Biological Chemistry, University of Verona, Strada Le Grazie, 8, 37134, Verona, Italy
| | - Giovanni Bisello
- Department of Neuroscience, Biomedicine and Movement Sciences, Section of Biological Chemistry, University of Verona, Strada Le Grazie, 8, 37134, Verona, Italy
| | - Mirco Dindo
- Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Okinawa, 904-0412, Japan
| | - Giada Rossignoli
- Molecular Neurosciences, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, 30 Guildford Street, London, WC1N 1EH, UK
| | - Carla Borri Voltattorni
- Department of Neuroscience, Biomedicine and Movement Sciences, Section of Biological Chemistry, University of Verona, Strada Le Grazie, 8, 37134, Verona, Italy
| | - Mariarita Bertoldi
- Department of Neuroscience, Biomedicine and Movement Sciences, Section of Biological Chemistry, University of Verona, Strada Le Grazie, 8, 37134, Verona, Italy.
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22
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Kojima K, Nakajima T, Taga N, Miyauchi A, Kato M, Matsumoto A, Ikeda T, Nakamura K, Kubota T, Mizukami H, Ono S, Onuki Y, Sato T, Osaka H, Muramatsu SI, Yamagata T. Gene therapy improves motor and mental function of aromatic l-amino acid decarboxylase deficiency. Brain 2019; 142:322-333. [PMID: 30689738 PMCID: PMC6377184 DOI: 10.1093/brain/awy331] [Citation(s) in RCA: 94] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 11/07/2018] [Indexed: 12/01/2022] Open
Abstract
In patients with aromatic l-amino acid decarboxylase (AADC) deficiency, a decrease in catecholamines and serotonin levels in the brain leads to developmental delay and movement disorders. The beneficial effects of gene therapy in patients from 1 to 8 years of age with homogeneous severity of disease have been reported from Taiwan. We conducted an open-label phase 1/2 study of population including adolescent patients with different degrees of severity. Six patients were enrolled: four males (ages 4, 10, 15 and 19 years) and one female (age 12 years) with a severe phenotype who were not capable of voluntary movement or speech, and one female (age 5 years) with a moderate phenotype who could walk with support. The patients received a total of 2 × 1011 vector genomes of adeno-associated virus vector harbouring DDC via bilateral intraputaminal infusions. At up to 2 years after gene therapy, the motor function was remarkably improved in all patients. Three patients with the severe phenotype were able to stand with support, and one patient could walk with a walker, while the patient with the moderate phenotype could run and ride a bicycle. This moderate-phenotype patient also showed improvement in her mental function, being able to converse fluently and perform simple arithmetic. Dystonia disappeared and oculogyric crisis was markedly decreased in all patients. The patients exhibited transient choreic dyskinesia for a couple of months, but no adverse events caused by vector were observed. PET with 6-[18F]fluoro-l-m-tyrosine, a specific tracer for AADC, showed a persistently increased uptake in the broad areas of the putamen. In our study, older patients (>8 years of age) also showed improvement, although treatment was more effective in younger patients. The genetic background of our patients was heterogeneous, and some patients suspected of having remnant enzyme activity showed better improvement than the Taiwanese patients. In addition to the alleviation of motor symptoms, the cognitive and verbal functions were improved in a patient with the moderate phenotype. The restoration of dopamine synthesis in the putamen via gene transfer provides transformative medical benefit across all patient ages, genotypes, and disease severities included in this study, with the most pronounced improvements noted in moderate patients.
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Affiliation(s)
- Karin Kojima
- Department of Pediatrics, Jichi Medical University, Shimotsuke, Tochigi, Japan
| | - Takeshi Nakajima
- Department of Neurosurgery, Jichi Medical University, Shimotsuke, Tochigi, Japan
| | - Naoyuki Taga
- Department of Anesthesiology and Critical Care Medicine, Division of Anesthesiology, Jichi Medical University, Shimotsuke, Tochigi, Japan
| | - Akihiko Miyauchi
- Department of Pediatrics, Jichi Medical University, Shimotsuke, Tochigi, Japan
| | - Mitsuhiro Kato
- Department of Pediatrics, Showa University, Shinagawa, Tokyo, Japan.,Department of Pediatrics, Yamagata University Faculty of Medicine, Yamagata, Yamagata, Japan
| | - Ayumi Matsumoto
- Department of Pediatrics, Jichi Medical University, Shimotsuke, Tochigi, Japan
| | - Takahiro Ikeda
- Department of Pediatrics, Jichi Medical University, Shimotsuke, Tochigi, Japan
| | - Kazuyuki Nakamura
- Department of Pediatrics, Yamagata University Faculty of Medicine, Yamagata, Yamagata, Japan
| | - Tetsuo Kubota
- Department of Pediatrics, Anjo Kosei Hospital, Anjo, Aichi, Japan
| | - Hiroaki Mizukami
- Division of Genetic Therapeutics, Jichi Medical University, Shimotsuke, Tochigi, Japan
| | - Sayaka Ono
- Division of Neurology, Department of Medicine, Jichi Medical University, Shimotsuke, Tochigi, Japan
| | - Yoshiyuki Onuki
- Department of Neurosurgery, Jichi Medical University, Shimotsuke, Tochigi, Japan
| | | | - Hitoshi Osaka
- Department of Pediatrics, Jichi Medical University, Shimotsuke, Tochigi, Japan
| | - Shin-Ichi Muramatsu
- Division of Genetic Therapeutics, Jichi Medical University, Shimotsuke, Tochigi, Japan.,Division of Neurology, Department of Medicine, Jichi Medical University, Shimotsuke, Tochigi, Japan.,Center for Gene and Cell Therapy, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, Japan
| | - Takanori Yamagata
- Department of Pediatrics, Jichi Medical University, Shimotsuke, Tochigi, Japan
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23
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Montioli R, Battini R, Paiardini A, Tolve M, Bertoldi M, Carducci C, Leuzzi V, Borri Voltattorni C. A novel compound heterozygous genotype associated with aromatic amino acid decarboxylase deficiency: Clinical aspects and biochemical studies. Mol Genet Metab 2019; 127:132-137. [PMID: 31104889 DOI: 10.1016/j.ymgme.2019.05.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 05/07/2019] [Accepted: 05/07/2019] [Indexed: 11/25/2022]
Abstract
Aromatic amino acid decarboxylase (AADC) deficiency is a rare autosomal neurometabolic disorder caused by a deficit of AADC, a pyridoxal 5'-phosphate (PLP)-dependent enzyme, which catalyzes the synthesis of dopamine and serotonin. While many studies have highlighted the molecular defects of the homozygous pathogenic variants, so far only a study investigated heterozygous variants at protein level. Here, we report a clinical case of one AADC deficiency compound heterozygous patient bearing the A91V mutation and the novel C410G mutation. To elucidate its enzymatic phenotype, the A91V and C410G homodimers were first expressed in Escherichia coli, purified and characterized. Although both apo variants display an unaltered overall tertiary structure, they show a ̴ 20-fold decreased PLP binding affinity. The C410G mutation only causes a ̴ 4-fold decrease of the catalytic efficiency, while the A91V mutation causes a 1300-fold decrease of the kcat/Km, and changes in the holoAADC consisting in a marked alteration of the tertiary structure and the coenzyme microenvironment. Structural analyses of these mutations are in agreement with these data. Unfortunately, the C410G/A91V heterodimer was constructed, expressed and purified in rather modest amount. Anyway, measurements of decarboxylase activity indicate that its putative kcat value is lower than that predicted by averaging the kcat values of the two parental enzymes. This indicates a negative interallelic complementation between the C410G and A91V monomers. Overall, this study allowed to relate the clinical to the enzymatic phenotype of the patient and to extend knowledge in the clinical and molecular pathogenesis of AADC deficiency.
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Affiliation(s)
- Riccardo Montioli
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Roberta Battini
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy; IRCCS Fondazione Stella Maris, Pisa, Italy
| | - Alessandro Paiardini
- Department of Biochemical Sciences "A. Rossi Fanelli", University of Roma "La Sapienza", Roma, Italy
| | - Manuela Tolve
- Department of Experimental Medicine, University of Roma "La Sapienza", Roma, Italy; Clinical Pathology Unit, PoliclinicoUmberto 1, Roma, Italy
| | - Mariarita Bertoldi
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Carla Carducci
- Department of Experimental Medicine, University of Roma "La Sapienza", Roma, Italy
| | - Vincenzo Leuzzi
- Department of Human Neuroscience, University of Roma "La Sapienza", Roma, Italy.
| | - Carla Borri Voltattorni
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.
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24
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Himmelreich N, Montioli R, Bertoldi M, Carducci C, Leuzzi V, Gemperle C, Berner T, Hyland K, Thöny B, Hoffmann GF, Voltattorni CB, Blau N. Aromatic amino acid decarboxylase deficiency: Molecular and metabolic basis and therapeutic outlook. Mol Genet Metab 2019; 127:12-22. [PMID: 30952622 DOI: 10.1016/j.ymgme.2019.03.009] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 03/24/2019] [Accepted: 03/25/2019] [Indexed: 12/24/2022]
Abstract
Aromatic-l-amino acid decarboxylase (AADC) deficiency is an ultra-rare inherited autosomal recessive disorder characterized by sharply reduced synthesis of dopamine as well as other neurotransmitters. Symptoms, including hypotonia and movement disorders (especially oculogyric crisis and dystonia) as well as autonomic dysfunction and behavioral disorders, vary extensively and typically emerge in the first months of life. However, diagnosis is difficult, requiring analysis of metabolites in cerebrospinal fluid, assessment of plasma AADC activity, and/or DNA sequence analysis, and is frequently delayed for years. New metabolomics techniques promise early diagnosis of AADC deficiency by detection of 3-O-methyl-dopa in serum or dried blood spots. A total of 82 dopa decarboxylase (DDC) variants in the DDC gene leading to AADC deficiency have been identified and catalogued for all known patients (n = 123). Biochemical and bioinformatics studies provided insight into the impact of many variants. c.714+4A>T, p.S250F, p.R347Q, and p.G102S are the most frequent variants (cumulative allele frequency = 57%), and c.[714+4A>T];[714+4A>T], p.[S250F];[S250F], and p.[G102S];[G102S] are the most frequent genotypes (cumulative genotype frequency = 40%). Known or predicted molecular effect was defined for 79 variants. Most patients experience an unrelenting disease course with poor or no response to conventional medical treatments, including dopamine agonists, monoamine oxidase inhibitors, and pyridoxine derivatives. The advent of gene therapy represents a potentially promising new avenue for treatment of patients with AADC deficiency. Clinical studies based on the direct infusion of engineered adeno-associated virus type 2 vectors into the putamen have demonstrated acceptable safety and tolerability and encouraging improvement in motor milestones and cognitive symptoms. The success of gene therapy in AADC deficiency treatment will depend on timely diagnosis to facilitate treatment administration before the onset of neurologic damage.
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Affiliation(s)
- Nastassja Himmelreich
- Dietmar-Hopp Metabolic Center and Centre for Pediatrics and Adolescent Medicine, University Children's Hospital, Heidelberg, Germany
| | - Riccardo Montioli
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Mariarita Bertoldi
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Carla Carducci
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
| | - Vincenzo Leuzzi
- Department of Human Neuroscience, Sapienza University of Rome, Rome, Italy
| | - Corinne Gemperle
- Department of Pediatrics, Divisions of Metabolism and of Clinical Chemistry and Biochemistry, University of Zürich, Zürich, Switzerland
| | - Todd Berner
- Global Medical Affairs, PTC Therapeutics, South Plainfield, NJ, USA
| | - Keith Hyland
- Medical Neurogenetics Laboratories, Atlanta, GA, USA
| | - Beat Thöny
- Department of Pediatrics, Divisions of Metabolism and of Clinical Chemistry and Biochemistry, University of Zürich, Zürich, Switzerland
| | - Georg F Hoffmann
- Dietmar-Hopp Metabolic Center and Centre for Pediatrics and Adolescent Medicine, University Children's Hospital, Heidelberg, Germany
| | - Carla B Voltattorni
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.
| | - Nenad Blau
- Dietmar-Hopp Metabolic Center and Centre for Pediatrics and Adolescent Medicine, University Children's Hospital, Heidelberg, Germany.
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25
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Dai L, Ding C, Fang F. A novel DDC gene deletion mutation in two Chinese mainland siblings with aromatic l-amino acid decarboxylase deficiency. Brain Dev 2019; 41:205-209. [PMID: 30144970 DOI: 10.1016/j.braindev.2018.08.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Revised: 08/07/2018] [Accepted: 08/08/2018] [Indexed: 12/23/2022]
Abstract
BACKGROUND Aromatic l-amino acid decarboxylase (AADC) deficiency (OMIM #608643) is a rare and severe disorder of biogenic amine synthesis caused by mutations in the DDC gene. The phenomenology of the movement disorder includes intermittent oculogyric crises and limb dystonia, generalized athetosis, and impaired voluntary movement. OBJECTIVE To identify clinical manifestations and DDC gene mutations in two Chinese mainland children who are siblings with AADC deficiency. METHODS We used targeted next-generation sequencing and quantitative polymerase chain reaction (qPCR) to reveal DDC mutations in these children. RESULTS Two DDC gene mutations were found: one missense mutation, c.1040G > A (p.Arg347Gln), is a reported mutation derived from the mother; the other mutation, a whole-exon 11 and 12 deletion, is a novel mutation derived from the father. The index patient and her brother both had poor sucking power and feeding difficulty at birth and episodes of oculogyric crises, truncal hypotonia, limb hypertonia, sleep disturbances, irritability, and motor delay. The siblings both died at 1 year and 10 months due to asphyxia and pneumonia during gaze and hypertonia episodes. CONCLUSION This study identified a novel DDC gene deletion mutation in two siblings with AADC deficiency disease in the Chinese mainland population.
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Affiliation(s)
- Lifang Dai
- Department of Neurology, Beijing Children's Hospital, Capital Medical University, National Center For Children's Health, 100045, China
| | - Changhong Ding
- Department of Neurology, Beijing Children's Hospital, Capital Medical University, National Center For Children's Health, 100045, China.
| | - Fang Fang
- Department of Neurology, Beijing Children's Hospital, Capital Medical University, National Center For Children's Health, 100045, China.
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26
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Lee NC, Chien YH, Hwu WL. A review of aromatic l
-amino acid decarboxylase (AADC) deficiency in Taiwan. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2019; 181:226-229. [DOI: 10.1002/ajmg.c.31670] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 11/27/2018] [Accepted: 11/29/2018] [Indexed: 12/11/2022]
Affiliation(s)
- Ni-Chung Lee
- Department of Medical Genetics; National Taiwan University Hospital and National Taiwan University College of Medicine; Taipei Taiwan
- Department of Pediatrics; National Taiwan University Hospital and National Taiwan University College of Medicine; Taipei Taiwan
| | - Yin-Hsiu Chien
- Department of Medical Genetics; National Taiwan University Hospital and National Taiwan University College of Medicine; Taipei Taiwan
- Department of Pediatrics; National Taiwan University Hospital and National Taiwan University College of Medicine; Taipei Taiwan
| | - Wuh-Liang Hwu
- Department of Medical Genetics; National Taiwan University Hospital and National Taiwan University College of Medicine; Taipei Taiwan
- Department of Pediatrics; National Taiwan University Hospital and National Taiwan University College of Medicine; Taipei Taiwan
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27
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Parthasarathy A, Cross PJ, Dobson RCJ, Adams LE, Savka MA, Hudson AO. A Three-Ring Circus: Metabolism of the Three Proteogenic Aromatic Amino Acids and Their Role in the Health of Plants and Animals. Front Mol Biosci 2018; 5:29. [PMID: 29682508 PMCID: PMC5897657 DOI: 10.3389/fmolb.2018.00029] [Citation(s) in RCA: 166] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2017] [Accepted: 03/21/2018] [Indexed: 12/19/2022] Open
Abstract
Tyrosine, phenylalanine and tryptophan are the three aromatic amino acids (AAA) involved in protein synthesis. These amino acids and their metabolism are linked to the synthesis of a variety of secondary metabolites, a subset of which are involved in numerous anabolic pathways responsible for the synthesis of pigment compounds, plant hormones and biological polymers, to name a few. In addition, these metabolites derived from the AAA pathways mediate the transmission of nervous signals, quench reactive oxygen species in the brain, and are involved in the vast palette of animal coloration among others pathways. The AAA and metabolites derived from them also have integral roles in the health of both plants and animals. This review delineates the de novo biosynthesis of the AAA by microbes and plants, and the branching out of AAA metabolism into major secondary metabolic pathways in plants such as the phenylpropanoid pathway. Organisms that do not possess the enzymatic machinery for the de novo synthesis of AAA must obtain these primary metabolites from their diet. Therefore, the metabolism of AAA by the host animal and the resident microflora are important for the health of all animals. In addition, the AAA metabolite-mediated host-pathogen interactions in general, as well as potential beneficial and harmful AAA-derived compounds produced by gut bacteria are discussed. Apart from the AAA biosynthetic pathways in plants and microbes such as the shikimate pathway and the tryptophan pathway, this review also deals with AAA catabolism in plants, AAA degradation via the monoamine and kynurenine pathways in animals, and AAA catabolism via the 3-aryllactate and kynurenine pathways in animal-associated microbes. Emphasis will be placed on structural and functional aspects of several key AAA-related enzymes, such as shikimate synthase, chorismate mutase, anthranilate synthase, tryptophan synthase, tyrosine aminotransferase, dopachrome tautomerase, radical dehydratase, and type III CoA-transferase. The past development and current potential for interventions including the development of herbicides and antibiotics that target key enzymes in AAA-related pathways, as well as AAA-linked secondary metabolism leading to antimicrobials are also discussed.
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Affiliation(s)
- Anutthaman Parthasarathy
- Thomas H. Gosnell School of Life Sciences, Rochester Institute of Technology, Rochester, NY, United States
| | - Penelope J. Cross
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Renwick C. J. Dobson
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, Australia
| | - Lily E. Adams
- Thomas H. Gosnell School of Life Sciences, Rochester Institute of Technology, Rochester, NY, United States
| | - Michael A. Savka
- Thomas H. Gosnell School of Life Sciences, Rochester Institute of Technology, Rochester, NY, United States
| | - André O. Hudson
- Thomas H. Gosnell School of Life Sciences, Rochester Institute of Technology, Rochester, NY, United States
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28
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Caine C, Shohat M, Kim JK, Nakanishi K, Homma S, Mosharov EV, Monani UR. A pathogenic S250F missense mutation results in a mouse model of mild aromatic l-amino acid decarboxylase (AADC) deficiency. Hum Mol Genet 2018; 26:4406-4415. [PMID: 28973165 DOI: 10.1093/hmg/ddx326] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2017] [Accepted: 08/15/2017] [Indexed: 01/05/2023] Open
Abstract
Homozygous mutations in the aromatic l-amino acid decarboxylase (AADC) gene result in a severe depletion of its namesake protein, triggering a debilitating and often fatal form of infantile Parkinsonism known as AADC deficiency. AADC deficient patients fail to produce normal levels of the monoamine neurotransmitters dopamine and serotonin, and suffer a multi-systemic disorder characterized by movement abnormalities, developmental delay and autonomic dysfunction; an absolute loss of dopamine is generally considered incompatible with life. There is no optimal treatment for AADC deficiency and few truly good models in which to investigate disease mechanisms or develop and refine therapeutic strategies. In this study, we introduced a relatively frequently reported but mildly pathogenic S250F missense mutation into the murine Aadc gene. We show that mutants homozygous for the mutation are viable and express a stable but minimally active form of the AADC protein. Although the low enzymatic activity of the protein resulted in only modestly reduced concentrations of brain dopamine, serotonin levels were markedly diminished, and this perturbed behavior as well as autonomic function in mutant mice. Still, we found no evidence of morphologic abnormalities of the dopaminergic cells in mutant brains. The striatum as well as substantia nigra appeared normal and no loss of dopamine expressing cells in the latter was detected. We conclude that even minute levels of active AADC are sufficient to allow for substantial amounts of dopamine to be produced in model mice harboring the S250F mutation. Such mutants represent a novel, mild model of human AADC deficiency.
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Affiliation(s)
- Charlotte Caine
- Department of Pathology and Cell Biology.,Center for Motor Neuron Biology and Disease
| | - Meytal Shohat
- Department of Pathology and Cell Biology.,Center for Motor Neuron Biology and Disease
| | - Jeong-Ki Kim
- Department of Pathology and Cell Biology.,Center for Motor Neuron Biology and Disease
| | | | | | - Eugene V Mosharov
- Department of Neurology.,Department of Psychiatry, Columbia University Medical Center, New York, NY 10032, USA.,New York State Psychiatric Institute, New York, NY 10032, USA
| | - Umrao R Monani
- Department of Pathology and Cell Biology.,Center for Motor Neuron Biology and Disease.,Department of Neurology
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29
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Montioli R, Janson G, Paiardini A, Bertoldi M, Borri Voltattorni C. Heterozygosis in aromatic amino acid decarboxylase deficiency: Evidence for a positive interallelic complementation between R347Q and R358H mutations. IUBMB Life 2018; 70:215-223. [PMID: 29356298 DOI: 10.1002/iub.1718] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 01/03/2018] [Indexed: 11/08/2022]
Abstract
Aromatic amino acid or Dopa decarboxylase (AADC or DDC) is a homodimeric pyridoxal 5'-phosphate (PLP) enzyme responsible for the generation of the neurotransmitters dopamine and serotonin. AADC deficiency is a rare inborn disease caused by mutations of the AADC gene leading to a defect of AADC enzyme and resulting in impaired dopamine and serotonin synthesis. Until now, only the molecular effects of homozygous mutations were analyzed. However, although heterozygous carriers of AADC deficiency were identified, the molecular aspects of their enzymatic phenotypes are not yet investigated. Here, we focus our attention on the R347Q/R358H and R347Q/R160W heterozygous mutations, and report for the first time the isolation and characterization, in the purified recombinant form, of the R347Q/R358H heterodimer and of the R358H homodimer. The results, integrated with those already known of the R347Q homodimeric variant, provide evidence that (i) the R358H mutation strongly reduces the PLP-binding affinity and the catalytic activity, and (ii) a positive interallelic complementation exists between the R347Q and the R358H mutations. Bioinformatics analyses provide the structural basis for these data. Unfortunately, the R347Q/R160W heterodimer was not obtained in a sufficient amount to allow its purification and characterization. Nevertheless, the biochemical features of the R160W homodimer give a contribution to the enzymatic phenotype of the heterozygous R347Q/R160W and suggest the possible relevance of Arg160 in the proper folding of human DDC. © 2018 IUBMB Life, 70(3):215-223, 2018.
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Affiliation(s)
- Riccardo Montioli
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Giacomo Janson
- Department of Biochemical Sciences "A. Rossi Fanelli,", Sapienza University of Rome, Rome, Italy
| | - Alessandro Paiardini
- Department of Biochemical Sciences "A. Rossi Fanelli,", Sapienza University of Rome, Rome, Italy
| | - Mariarita Bertoldi
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Carla Borri Voltattorni
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
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Montioli R, Zamparelli C, Borri Voltattorni C, Cellini B. Oligomeric State and Thermal Stability of Apo- and Holo- Human Ornithine δ-Aminotransferase. Protein J 2017; 36:174-185. [PMID: 28345116 PMCID: PMC5432616 DOI: 10.1007/s10930-017-9710-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Human ornithine δ-aminotransferase (hOAT) (EC 2.6.1.13) is a mitochondrial pyridoxal 5′-phosphate (PLP)-dependent aminotransferase whose deficit is associated with gyrate atrophy, a rare autosomal recessive disorder causing progressive blindness and chorioretinal degeneration. Here, both the apo- and holo-form of recombinant hOAT were characterized by means of spectroscopic, kinetic, chromatographic and computational techniques. The results indicate that apo and holo-hOAT (a) show a similar tertiary structure, even if apo displays a more pronounced exposure of hydrophobic patches, (b) exhibit a tetrameric structure with a tetramer-dimer equilibrium dissociation constant about fivefold higher for the apoform with respect to the holoform, and (c) have apparent Tm values of 46 and 67 °C, respectively. Moreover, unlike holo-hOAT, apo-hOAT is prone to unfolding and aggregation under physiological conditions. We also identified Arg217 as an important hot-spot at the dimer–dimer interface of hOAT and demonstrated that the artificial dimeric variant R217A exhibits spectroscopic properties, Tm values and catalytic features similar to those of the tetrameric species. This finding indicates that the catalytic unit of hOAT is the dimer. However, under physiological conditions the apo-tetramer is slightly less prone to unfolding and aggregation than the apo-dimer. The possible implications of the data for the intracellular stability and regulation of hOAT are discussed.
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Affiliation(s)
- Riccardo Montioli
- Department of Neuroscience, Biomedicine and Movement Sciences (Section of Biological Chemistry), University of Verona, Strada Le Grazie 8, 37134, Verona, Italy.
| | | | - Carla Borri Voltattorni
- Department of Neuroscience, Biomedicine and Movement Sciences (Section of Biological Chemistry), University of Verona, Strada Le Grazie 8, 37134, Verona, Italy
| | - Barbara Cellini
- Department of Neuroscience, Biomedicine and Movement Sciences (Section of Biological Chemistry), University of Verona, Strada Le Grazie 8, 37134, Verona, Italy
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Wassenberg T, Molero-Luis M, Jeltsch K, Hoffmann GF, Assmann B, Blau N, Garcia-Cazorla A, Artuch R, Pons R, Pearson TS, Leuzzi V, Mastrangelo M, Pearl PL, Lee WT, Kurian MA, Heales S, Flint L, Verbeek M, Willemsen M, Opladen T. Consensus guideline for the diagnosis and treatment of aromatic l-amino acid decarboxylase (AADC) deficiency. Orphanet J Rare Dis 2017; 12:12. [PMID: 28100251 PMCID: PMC5241937 DOI: 10.1186/s13023-016-0522-z] [Citation(s) in RCA: 133] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2016] [Accepted: 10/04/2016] [Indexed: 01/17/2023] Open
Abstract
Aromatic L-amino acid decarboxylase deficiency (AADCD) is a rare, autosomal recessive neurometabolic disorder that leads to a severe combined deficiency of serotonin, dopamine, norepinephrine and epinephrine. Onset is early in life, and key clinical symptoms are hypotonia, movement disorders (oculogyric crisis, dystonia, and hypokinesia), developmental delay, and autonomic symptoms.In this consensus guideline, representatives of the International Working Group on Neurotransmitter Related Disorders (iNTD) and patient representatives evaluated all available evidence for diagnosis and treatment of AADCD and made recommendations using SIGN and GRADE methodology. In the face of limited definitive evidence, we constructed practical recommendations on clinical diagnosis, laboratory diagnosis, imaging and electroencephalograpy, medical treatments and non-medical treatments. Furthermore, we identified topics for further research. We believe this guideline will improve the care for AADCD patients around the world whilst promoting general awareness of this rare disease.
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Affiliation(s)
- Tessa Wassenberg
- Department of Neurology and Child Neurology, Radboud university medical center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Marta Molero-Luis
- Department of Clinical Biochemistry, CIBERER-ISCIII, Hospital Sant Joan de Déu Barcelona, Barcelona, Spain
| | - Kathrin Jeltsch
- Department of Child Neurology and Metabolic Disorders, University Children’s Hospital, Heidelberg, Germany
| | - Georg F. Hoffmann
- Department of Child Neurology and Metabolic Disorders, University Children’s Hospital, Heidelberg, Germany
| | - Birgit Assmann
- Department of Child Neurology and Metabolic Disorders, University Children’s Hospital, Heidelberg, Germany
| | - Nenad Blau
- Dietmar-Hopp Metabolic Center, University Children’s Hospital Heidelberg, Heidelberg, Germany
| | - Angeles Garcia-Cazorla
- Department of Child Neurology, CIBERER-ISCIII, Hospital Sant Joan de Déu Barcelona, Barcelona, Spain
| | - Rafael Artuch
- Department of Clinical Biochemistry, CIBERER-ISCIII, Hospital Sant Joan de Déu Barcelona, Barcelona, Spain
| | - Roser Pons
- First Department of Pediatrics, Pediatric Neurology Unit, Agia Sofia Hospital, National and Kapodistrian University of Athens, Athens, Greece
| | - Toni S. Pearson
- Department of Neurology, Washington University School of Medicine, St. Louis, USA
| | - Vincenco Leuzzi
- Department of Pediatrics and Child Neuropsychiatry, Sapienza Università di Roma, Rome, Italy
| | - Mario Mastrangelo
- Department of Pediatrics and Child Neuropsychiatry, Sapienza Università di Roma, Rome, Italy
| | - Phillip L. Pearl
- Department of Epilepsy and Clinical Neurophysiology, Boston Children’s Hospital, Harvard Medical School, Boston, USA
| | - Wang Tso Lee
- Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan
| | - Manju A. Kurian
- Developmental Neurosciences, UCL- Institute of Child Health and Department of Neurology, Great Ormond Street Hospital for Children NHS Foundations Trust, London, UK
| | - Simon Heales
- Laboratory Medicine, Great Ormond Street Hospital and Neurometabolic Unit, National Hospital, London, UK
| | | | - Marcel Verbeek
- Department of Neurology and Child Neurology, Radboud university medical center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
- Department Laboratory Medicine, Alzheimer Centre, Radboud university medical center, Nijmegen, The Netherlands
| | - Michèl Willemsen
- Department of Neurology and Child Neurology, Radboud university medical center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Thomas Opladen
- Department of Child Neurology and Metabolic Disorders, University Children’s Hospital, Heidelberg, Germany
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Zhu J, Yu F. [Feeding difficulty and developmental delay for 8 months and nystagmus for 4 months in an infant]. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2017; 19:68-72. [PMID: 28100326 PMCID: PMC7390117 DOI: 10.7499/j.issn.1008-8830.2017.01.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 11/02/2016] [Indexed: 06/06/2023]
Abstract
Aromatic L-amino acid decarboxylase (AADC) deficiency is a rare autosomal recessive hereditary disease and is a congenital metabolic disorder of neurotransmitter biosynthesis. It is mainly manifested as hypotonia, oculogyric crisis, autonomic dysfunction, and developmental delay. This article reports a boy manifested as delayed motor development, hypotonia, and oculogyric crisis. Gene screening for metabolic disorders revealed new compound heterozygous mutations, c.1063dupA (p.I355fs) and c.250A>C (p.S84R), in the exon of DDC gene. The boy had a significant increase in 3-O-methyldopa as measured by dried blood spot. Therefore, he was diagnosed with AADC deficiency. After treatment with the dopamine receptor agonist pramipexole dihydrochloride, the catechol-O-methyltransferase inhibitor entacapone, and vitamin B6, the boy showed mild improvements in hypotonia, blepharoptosis, and oculogyric crisis. Clinical physicians should enhance their ability for identifying AADC deficiency, so as to facilitate early diagnosis and treatment of this disorder. Genetic counseling for birth health and prenatal diagnosis should be performed for parents in need.
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Affiliation(s)
- Jie Zhu
- Department of Pediatric Endocrine and Genetic Metabolic Disease, Maternal and Children's Hospital of Hubei Province, Wuhan 430070, China.
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Sanchez-Jiménez F, Pino-Ángeles A, Rodríguez-López R, Morales M, Urdiales JL. Structural and functional analogies and differences between histidine decarboxylase and aromatic l-amino acid decarboxylase molecular networks: Biomedical implications. Pharmacol Res 2016; 114:90-102. [DOI: 10.1016/j.phrs.2016.08.032] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 08/29/2016] [Accepted: 08/29/2016] [Indexed: 01/24/2023]
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Kojima K, Anzai R, Ohba C, Goto T, Miyauchi A, Thöny B, Saitsu H, Matsumoto N, Osaka H, Yamagata T. A female case of aromatic l-amino acid decarboxylase deficiency responsive to MAO-B inhibition. Brain Dev 2016; 38:959-963. [PMID: 27371992 DOI: 10.1016/j.braindev.2016.06.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Revised: 05/22/2016] [Accepted: 06/04/2016] [Indexed: 11/24/2022]
Abstract
BACKGROUND Aromatic l-amino acid decarboxylase (AADC) deficiency is an autosomal recessive disorder, caused by defects in the DDC gene. AADC catalyzes the synthesis of the neurotransmitters dopamine and serotonin from l-dopa and 5-HT respectively. Most patients are bed ridden for life, with little response to treatment. We now report one female patient who improved her motor and cognitive function after being prescribed a MAO-B inhibitor. CASE A five years old female presented with the typical clinical features of AADC deficiency. She was floppy, with no head control, had intermittent limb dystonia, and an upward deviation of the eyes (oculogyric crisis). This patient possessed compound heterozygous mutations in DDC (p.Trp105Cys, p.Pro129Ser), with a CSF draw indicating abnormal patterns of biogenic amine metabolites, compatible with AADC deficiency. RESULTS After her diagnosis at 3years of age, medication with levodopa and vitamin B6 failed to show any efficacy. Subsequent administration with a MAO-B inhibitor improved her psychomotor functions to the extent that at 5years of age she could walk several meters with support. CONCLUSION Our analyses of chemical findings, together with in silico structure predictions, lead us to hypothesize that this patient retained some AADC activity. In these cases, accurate diagnosis and early treatment should improve patient outcome.
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Affiliation(s)
- Karin Kojima
- Department of Pediatrics, Jichi Medical University, Japan
| | - Rie Anzai
- Department of Neurology, Kanagawa Children's Medical Center, Japan
| | - Chihiro Ohba
- Department of Pediatrics, University of Zürich, Switzerland
| | - Tomohide Goto
- Department of Neurology, Kanagawa Children's Medical Center, Japan
| | | | - Beat Thöny
- Department of Pediatrics, University of Zürich, Switzerland
| | - Hirotomo Saitsu
- Department of Human Genetics, Yokohama City University, Graduate School of Medicine, Japan; Department of Biochemistry, Hamamatsu Medical University, Japan
| | - Naomichi Matsumoto
- Department of Human Genetics, Yokohama City University, Graduate School of Medicine, Japan
| | - Hitoshi Osaka
- Department of Pediatrics, Jichi Medical University, Japan.
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Badar S, Busti F, Ferrarini A, Xumerle L, Bozzini P, Capelli P, Pozzi-Mucelli R, Campostrini N, De Matteis G, Marin Vargas S, Giorgetti A, Delledonne M, Olivieri O, Girelli D. Identification of novel mutations in hemochromatosis genes by targeted next generation sequencing in Italian patients with unexplained iron overload. Am J Hematol 2016; 91:420-5. [PMID: 26799139 DOI: 10.1002/ajh.24304] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 01/08/2016] [Accepted: 01/13/2016] [Indexed: 12/14/2022]
Abstract
Hereditary hemochromatosis, one of the commonest genetic disorder in Caucasians, is mainly associated to homozygosity for the C282Y mutation in the HFE gene, which is highly prevalent (allele frequency up to near 10% in Northern Europe) and easily detectable through a widely available "first level" molecular test. However, in certain geographical regions like the Mediterranean area, up to 30% of patients with a HH phenotype has a negative or non-diagnostic (i.e. simple heterozygosity) test, because of a known heterogeneity involving at least four other genes (HAMP, HJV, TFR2, and SLC40A1). Mutations in such genes are generally rare/private, making the diagnosis of atypical HH essentially a matter of exclusion in clinical practice (from here the term of "non-HFE" HH), unless cumbersome traditional sequencing is applied. We developed a Next Generation Sequencing (NGS)-based test targeting the five HH genes, and applied it to patients with clinically relevant iron overload (IO) and a non-diagnostic first level genetic test. We identified several mutations, some of which were novel (i.e. HFE W163X, HAMP R59X, and TFR2 D555N) and allowed molecular reclassification of "non-HFE" HH clinical diagnosis, particularly in some highly selected IO patients without concurring acquired risk factors. This NGS-based "second level" genetic test may represent a useful tool for molecular diagnosis of HH in patients in whom HH phenotype remains unexplained after the search of common HFE mutations.
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Affiliation(s)
- Sadaf Badar
- Department of Medicine; Section of Internal Medicine, University of Verona; Verona Italy
| | - Fabiana Busti
- Department of Medicine; Section of Internal Medicine, University of Verona; Verona Italy
| | | | - Luciano Xumerle
- Department of Biotechnology; University of Verona; Verona Italy
| | - Paolo Bozzini
- Department of Medicine; Section of Internal Medicine, University of Verona; Verona Italy
| | - Paola Capelli
- Unit of Pathology, Azienda Ospedaliera Universitaria Integrata Verona; Verona Italy
| | - Roberto Pozzi-Mucelli
- Department of Diagnostics and Public Health; Section of Radiology, University of Verona; Verona Italy
| | - Natascia Campostrini
- Department of Medicine; Section of Internal Medicine, University of Verona; Verona Italy
| | - Giovanna De Matteis
- Unit of Clinical Chemistry, Azienda Ospedaliera Universitaria Integrata Verona; Verona Italy
| | | | | | | | - Oliviero Olivieri
- Department of Medicine; Section of Internal Medicine, University of Verona; Verona Italy
| | - Domenico Girelli
- Department of Medicine; Section of Internal Medicine, University of Verona; Verona Italy
- Veneto Regional Referral Center for Iron Metabolism Disorders, GIMFer (Gruppo Interdisciplinare Sulle Malattie Del Ferro); Azienda Ospedaliera Uiversitaria Integrata Verona; Verona Italy
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Montioli R, Paiardini A, Kurian MA, Dindo M, Rossignoli G, Heales SJR, Pope S, Voltattorni CB, Bertoldi M. The novel R347g pathogenic mutation of aromatic amino acid decarboxylase provides additional molecular insights into enzyme catalysis and deficiency. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2016; 1864:676-682. [PMID: 26994895 DOI: 10.1016/j.bbapap.2016.03.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 03/15/2016] [Accepted: 03/15/2016] [Indexed: 10/22/2022]
Abstract
We report here a clinical case of a patient with a novel mutation (Arg347→Gly) in the gene encoding aromatic amino acid decarboxylase (AADC) that is associated with AADC deficiency. The variant R347G in the purified recombinant form exhibits, similarly to the pathogenic mutation R347Q previously studied, a 475-fold drop of kcat compared to the wild-type enzyme. In attempting to unravel the reason(s) for this catalytic defect, we have carried out bioinformatics analyses of the crystal structure of AADC-carbidopa complex with the modelled catalytic loop (residues 328-339). Arg347 appears to interact with Phe103, as well as with both Leu333 and Asp345. We have then prepared and characterized the artificial F103L, R347K and D345A mutants. F103L, D345A and R347K exhibit about 13-, 97-, and 345-fold kcat decrease compared to the wild-type AADC, respectively. However, unlike F103L, the R347G, R347K and R347Q mutants as well as the D345A variant appear to be more defective in catalysis than in protein folding. Moreover, the latter mutants, unlike the wild-type protein and the F103L variant, share a peculiar binding mode of dopa methyl ester consisting of formation of a quinonoid intermediate. This finding strongly suggests that their catalytic defects are mainly due to a misplacement of the substrate at the active site. Taken together, our results highlight the importance of the Arg347-Leu333-Asp345 hydrogen-bonds network in the catalysis of AADC and reveal the molecular basis for the pathogenicity of the variants R347. Following the above results, a therapeutic treatment for patients bearing the mutation R347G is proposed.
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Affiliation(s)
- Riccardo Montioli
- Department of Neurosciences, Biomedicine and Movement, University of Verona, Verona, Italy
| | - Alessandro Paiardini
- Department of Biology and Biotechnology "Charles Darwin", La Sapienza University of Roma, Roma, Italy
| | - Manju A Kurian
- Developmental Neurosciences, UCL-Institute of Child Health, London, UK; Department of Neurology, Great Ormond Street Hospital, London, UK
| | - Mirco Dindo
- Department of Neurosciences, Biomedicine and Movement, University of Verona, Verona, Italy
| | - Giada Rossignoli
- Department of Neurosciences, Biomedicine and Movement, University of Verona, Verona, Italy
| | - Simon J R Heales
- Clinical Chemistry, Great Ormond Street Hospital, London, UK; Neurometabolic Unit, National Hospital of Neurology and Neurosurgery, UK
| | - Simon Pope
- Neurometabolic Unit, National Hospital of Neurology and Neurosurgery, UK
| | | | - Mariarita Bertoldi
- Department of Neurosciences, Biomedicine and Movement, University of Verona, Verona, Italy.
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Abstract
The monoamine neurotransmitter disorders are important genetic syndromes that cause disturbances in catecholamine (dopamine, noradrenaline and adrenaline) and serotonin homeostasis. These disorders result in aberrant monoamine synthesis, metabolism and transport. The clinical phenotypes are predominantly neurological, and symptoms resemble other childhood neurological disorders, such as dystonic or dyskinetic cerebral palsy, hypoxic ischaemic encephalopathy and movement disorders. As a consequence, monoamine neurotransmitter disorders are under-recognized and often misdiagnosed. The diagnosis of monoamine neurotransmitter disorders requires detailed clinical assessment, cerebrospinal fluid neurotransmitter analysis and further supportive diagnostic investigations. Prompt and accurate diagnosis of neurotransmitter disorders is paramount, as many are responsive to treatment. The treatment is usually mechanism-based, with the aim to reverse disturbances of monoamine synthesis and/or metabolism. Therapeutic intervention can lead to complete resolution of motor symptoms in some conditions, and considerably improve quality of life in others. In this Review, we discuss the clinical features, diagnosis and management of monoamine neurotransmitter disorders, and consider novel concepts, the latest advances in research and future prospects for therapy.
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Liver peroxisomal alanine:glyoxylate aminotransferase and the effects of mutations associated with Primary Hyperoxaluria Type I: An overview. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2015; 1854:1212-9. [PMID: 25620715 DOI: 10.1016/j.bbapap.2014.12.029] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 12/19/2014] [Accepted: 12/20/2014] [Indexed: 11/21/2022]
Abstract
Liver peroxisomal alanine:glyoxylate aminotransferase (AGT) (EC 2.6.1.44) catalyses the conversion of l-alanine and glyoxylate to pyruvate and glycine, a reaction that allows glyoxylate detoxification. Inherited mutations on the AGXT gene encoding AGT lead to Primary Hyperoxaluria Type I (PH1), a rare disorder characterized by the deposition of calcium oxalate crystals primarily in the urinary tract. Here we describe the results obtained on the biochemical features of AGT as well as on the molecular and cellular effects of polymorphic and pathogenic mutations. A complex scenario on the molecular pathogenesis of PH1 emerges in which the co-inheritance of polymorphic changes and the condition of homozygosis or compound heterozygosis are two important factors that determine the enzymatic phenotype of PH1 patients. All the reported data represent relevant steps toward the understanding of genotype/phenotype correlations, the prediction of the response of the patients to the available therapies, and the development of new therapeutic approaches. This article is part of a Special Issue entitled: Cofactor-dependent proteins: evolution, chemical diversity and bio-applications.
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Astegno A, Allegrini A, Piccoli S, Giorgetti A, Dominici P. Role of active-site residues Tyr55 and Tyr114 in catalysis and substrate specificity of Corynebacterium diphtheriae C-S lyase. Proteins 2014; 83:78-90. [PMID: 25354840 DOI: 10.1002/prot.24707] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 09/29/2014] [Accepted: 10/18/2014] [Indexed: 11/07/2022]
Abstract
In recent years, there has been increased interest in bacterial methionine biosynthesis enzymes as antimicrobial targets because of their pivotal role in cell metabolism. C-S lyase from Corynebacterium diphtheriae is a pyridoxal 5'-phosphate-dependent enzyme in the transsulfuration pathway that catalyzes the α,β-elimination of sulfur-containing amino acids, such as L-cystathionine, to generate ammonia, pyruvate, and homocysteine, the immediate precursor of L-methionine. In order to gain deeper insight into the functional and dynamic properties of the enzyme, mutants of two highly conserved active-site residues, Y55F and Y114F, were characterized by UV-visible absorbance, fluorescence, and CD spectroscopy in the absence and presence of substrates and substrate analogs, as well as by steady-state kinetic studies. Substitution of Tyr55 with Phe apparently causes a 130-fold decrease in K(d)(PLP) at pH 8.5 providing evidence that Tyr55 plays a role in cofactor binding. Moreover, spectral data show that the mutant accumulates the external aldimine intermediate suggesting that the absence of interaction between the hydroxyl moiety and PLP-binding residue Lys222 causes a decrease in the rate of substrate deprotonation. Mutation of Tyr114 with Phe slightly influences hydrolysis of L-cystathionine, and causes a change in substrate specificity towards L-serine and O-acetyl-L-serine compared to the wild type enzyme. These findings, together with computational data, provide useful insights in the substrate specificity of C-S lyase, which seems to be regulated by active-site architecture and by the specific conformation in which substrates are bound, and will aid in development of inhibitors.
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Affiliation(s)
- Alessandra Astegno
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, Verona, Italy
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