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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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Çınar M, Kılıç Yıldırım G, Kocagil S, Çilingir O. Spectrum of PAH gene mutations and genotype-phenotype correlation in patients with phenylalanine hydroxylase deficiency from Turkey. J Pediatr Endocrinol Metab 2022; 35:639-647. [PMID: 35355500 DOI: 10.1515/jpem-2022-0047] [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: 01/27/2022] [Accepted: 03/07/2022] [Indexed: 11/15/2022]
Abstract
OBJECTIVES The aim of our study was to define the genotype-phenotype correlations of mutations in the PAH gene among the Turkey's Central Anatolian region. METHODS Demographic characteristics of 108 patients with hyperphenylalaninemia (HPA) and 94 patients whose diagnosis was confirmed by PAH gene analysis (Sanger DNA Sequence Analysis and Next-Generation Sequencing) were determined retrospectively. Blood phenylalanine levels were analyzed using the high-performance liquid chromatography method. RESULTS Mild HPA-not-requiring-treatment (NT) was found in 50.9% of the patients, and a classical phenylketonuria (PKU) phenotype was found in 25.9%. Forty-seven types of variants were identified. The predominant variants were p.Ala403Val (9.9%), p.Ala300Ser (9.4%), and c.1066-11G>A (splicing) (9.4%). Missense mutations accounted for 68% of mutations and attenuated the clinical impact; splice variations were found in 14.8% of cases with severe features. The p.Thr380Met allele was specific to the mild HPA-NT group. The c.1066-11G>A (splicing) allele was associated with classical PKU, whereas the p.Arg408Trp allele was linked to severe symptoms. Three variations of unknown clinical significance were discovered: c.706+4A>T (splicing), c.843-5T>C (splicing), and p.Thr323=. Of these variants, the patient who was homozygous for the c.843-5T>C (splicing) allele related to the classical PKU phenotype. 70% of the patients who underwent tetrahydrobiopterin (BH4) test were responsive. Phenotypes that responded to BH4 treatment were mostly mild phenotypes. CONCLUSIONS The PAH genotype is the main factor that determines the phenotype of PKU. Establishing the relationship between the identified genetic mutations and phenotypic characteristics will provide very important data for each patient in terms of the specific management style.
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Affiliation(s)
- Müge Çınar
- Pediatrics, Bozüyük State Hospital, Bilecik, Turkey
| | - Gonca Kılıç Yıldırım
- Department of Paediatrics, Eskisehir Osmangazi University Faculty of Medicine, Division of Child Nutrition and Metabolism, Eskisehir, Turkey
- Eskisehir Osmangazi University Faculty of Medicine, Meselik Campuse, Odunpazari, Turkey
| | - Sinem Kocagil
- Eskisehir Osmangazi University Faculty of Medicine, Meselik Campuse, Odunpazari, Turkey
- Department of Genetics and Genomics Medicine, Eskisehir Osmangazi University Faculty of Medicine, Eskisehir, Turkey
| | - Oğuz Çilingir
- Eskisehir Osmangazi University Faculty of Medicine, Meselik Campuse, Odunpazari, Turkey
- Department of Genetics and Genomics Medicine, Eskisehir Osmangazi University Faculty of Medicine, Eskisehir, Turkey
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D'Apolito M, Ariano A, D'Andrea G, Tiscia G, Santacroce R, Maffione AB, Margaglione M. Identification of the novel G250R variant indicates a role for Thrombomodulin in modulating the risk for venous thromboembolism. Thromb Haemost 2022; 122:1827-1832. [PMID: 35436795 DOI: 10.1055/a-1827-7109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Thrombomodulin displays anticoagulant properties through thrombin binding and protein C activation. In close relatives who had a history of recurrent VTE, a missense variant (G250R) in the EGF-1 domain was identified. In an asymptomatic 250R carrier, higher thrombin generation plasma values were found. Evaluation of cells transfected with the wild-type or the mutant construct using imaging technologies and flow cytometry provided evidences that the 250R variant significantly decreased protein localization on cell membrane. The different pattern of cell distribution suggested that the 250R variant is not able to sufficiently target the plasma membrane. Present findings add information to characterize protein structure-function relationships, further suggesting that misfolding of the protein modulates the expression of mature protein. Functional analyses of the 250R variant increase our understanding of the role of Thrombomodulin in coagulation and support the hypothesis that gene variants reducing protein functionality cause deficiency and behave as a thrombophilic risk factor.
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Affiliation(s)
- Maria D'Apolito
- Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy
| | - Anastasia Ariano
- Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy
| | - Giovanna D'Andrea
- Genetica Medica - Scienze Biomediche, Università di Foggia, Foggia, Italy
| | - Giovanni Tiscia
- Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Rosa Santacroce
- Genetica Medica - Scienze Biomediche, Università di Foggia, Foggia, Italy
| | - Angela Bruna Maffione
- Human Anatomy, Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy
| | - Maurizio Margaglione
- Clinical and Experimentale Medicine, Medical Genetics, University of Foggia, Foggia, Foggia, Italy
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Pathogenic DNM1L Variant (1085G>A) Linked to Infantile Progressive Neurological Disorder: Evidence of Maternal Transmission by Germline Mosaicism and Influence of a Contemporary in cis Variant (1535T>C). Genes (Basel) 2021; 12:genes12091295. [PMID: 34573276 PMCID: PMC8467311 DOI: 10.3390/genes12091295] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/13/2021] [Accepted: 08/19/2021] [Indexed: 01/23/2023] Open
Abstract
Mitochondria are dynamic organelles undergoing continuous fusion and fission with Drp1, encoded by the DNM1L gene, required for mitochondrial fragmentation. DNM1L dominant pathogenic variants lead to progressive neurological disorders with early exitus. Herein we report on the case of a boy affected by epileptic encephalopathy carrying two heterozygous variants (in cis) of the DNM1L gene: a pathogenic variant (PV) c.1085G>A (p.Gly362Asp) accompanied with a variant of unknown significance (VUS) c.1535T>C (p.Ile512Thr). Amplicon sequencing of the mother’s DNA revealed the presence of the PV and VUS in 5% of cells, with the remaining cells presenting only VUS. Functional investigations performed on the patient and his mother’s cells unveiled altered mitochondrial respiratory chain activities, network architecture and Ca2+ homeostasis as compared with healthy unrelated subjects’ samples. Modelling Drp1 harbouring the two variants, separately or in combination, resulted in structural changes as compared with Wt protein. Considering the clinical history of the mother, PV transmission by a maternal germline mosaicism mechanism is proposed. Altered Drp1 function leads to changes in the mitochondrial structure and bioenergetics as well as in Ca2+ homeostasis. The novel VUS might be a modifier that synergistically worsens the phenotype when associated with the PV.
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Luca Tiscia G, Colaizzo D, Vergura P, Favuzzi G, Chinni E, Vandermeulen C, Detemmerman L, Grandone E. Loop-mediated isothermal amplification (LAMP)-based method for detecting factor V Leiden and factor II G20210A common variants. J Thromb Thrombolysis 2020; 50:908-912. [PMID: 32557225 DOI: 10.1007/s11239-020-02183-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Automated methodologies allowing for rapid detection of Factor V Leiden and Factor II G20210A variants are desirable, due to a high number of tested patients. Here, we report a preliminary validation of a CE-marked in vitro diagnostic (IVD) certified method for simultaneous detection of Factor V Leiden and Factor II G20210A variants on whole blood samples. The novel method is based on Loop-mediated isothermal AMPlification (LAMP) applied for a duplex detection of Factor V Leiden and Factor II G20210A variants without requiring prior DNA extraction, whereas the routine one is a TaqMan SNP genotyping targeting genomic DNA. We tested routine patients for both variants using novel and current methods and estimated concordance rate. Patients were tested under similar laboratory procedures. One hundred and eight patients referred for the thrombophilia testing in the period between 9th December 2019 to 27th February 2020 represented the study population. We routinely identified for the Factor V Leiden variant 163 wild-type, 17 heterozygotes and no homozygote. Concerning the Factor II G20210A variant, we identified 170 wild-type, nine heterozygotes and one homozygous carrier. Two heterozygotes carried both variants (double heterozygotes). The LAMP method showed a 100% concordance rate, detecting rightly all genotypes. The LAMP for a duplex detection of common thrombophilia variants shows analytic performances as good as those of the standard method.
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Affiliation(s)
- Giovanni Luca Tiscia
- UOSD e di Ricerca di Emostasi e Trombosi, Fondazione IRCCS Casa Sollievo della Sofferenza, 71013, San Giovanni Rotondo, FG, Italy
| | - Donatella Colaizzo
- UOSD e di Ricerca di Emostasi e Trombosi, Fondazione IRCCS Casa Sollievo della Sofferenza, 71013, San Giovanni Rotondo, FG, Italy
| | - Patrizia Vergura
- UOSD e di Ricerca di Emostasi e Trombosi, Fondazione IRCCS Casa Sollievo della Sofferenza, 71013, San Giovanni Rotondo, FG, Italy
| | - Giovanni Favuzzi
- UOSD e di Ricerca di Emostasi e Trombosi, Fondazione IRCCS Casa Sollievo della Sofferenza, 71013, San Giovanni Rotondo, FG, Italy
| | - Elena Chinni
- UOSD e di Ricerca di Emostasi e Trombosi, Fondazione IRCCS Casa Sollievo della Sofferenza, 71013, San Giovanni Rotondo, FG, Italy
| | | | | | - Elvira Grandone
- UOSD e di Ricerca di Emostasi e Trombosi, Fondazione IRCCS Casa Sollievo della Sofferenza, 71013, San Giovanni Rotondo, FG, Italy. .,Department of Obstetrics and Gynecology, First Moscow State Medical University, Moscow, Russia.
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Viganò S, D'Andrea G, Valle PD, Santacroce R, Margaglione M, D'Angelo A. A novel allele variant of the SERPINF2 gene responsible for severe plasmin inhibitor (α 2 -antiplasmin) deficiency in an Italian patient. Thromb Res 2018; 166:60-62. [DOI: 10.1016/j.thromres.2018.04.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 03/19/2018] [Accepted: 04/06/2018] [Indexed: 10/17/2022]
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Bafunno V, Firinu D, D'Apolito M, Cordisco G, Loffredo S, Leccese A, Bova M, Barca MP, Santacroce R, Cicardi M, Del Giacco S, Margaglione M. Mutation of the angiopoietin-1 gene (ANGPT1) associates with a new type of hereditary angioedema. J Allergy Clin Immunol 2018; 141:1009-1017. [PMID: 28601681 DOI: 10.1016/j.jaci.2017.05.020] [Citation(s) in RCA: 176] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 05/03/2017] [Accepted: 05/10/2017] [Indexed: 11/30/2022]
Affiliation(s)
- Valeria Bafunno
- Medical Genetics, Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy
| | - Davide Firinu
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Maria D'Apolito
- Medical Genetics, Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy
| | - Giorgia Cordisco
- Medical Genetics, Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy
| | - Stefania Loffredo
- Department of Translational Medical Sciences, University of Naples Federico II, Naples, Italy
| | - Angelica Leccese
- Medical Genetics, Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy
| | - Maria Bova
- Department of Translational Medical Sciences, University of Naples Federico II, Naples, Italy
| | - Maria Pina Barca
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Rosa Santacroce
- Medical Genetics, Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy
| | - Marco Cicardi
- Department of Biomedical and Clinical Sciences Luigi Sacco, University of Milan, Luigi Sacco Hospital Milan, Milan, Italy
| | - Stefano Del Giacco
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Maurizio Margaglione
- Medical Genetics, Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy.
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Akhmetova VL, Khusainova RI, Litvinov SS, Khusnutdinova EK. The carrier rate of the phenylalanine hydoxylase gene (PAH) mutations p.Arg408Trp, pArg261Gln, and p.Arg261X in the populations of Eurasia. RUSS J GENET+ 2017. [DOI: 10.1134/s1022795417060023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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9
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Trunzo R, Santacroce R, Shen N, Jung-Klawitter S, Leccese A, De Girolamo G, Margaglione M, Blau N. In vitro residual activity of phenylalanine hydroxylase variants and correlation with metabolic phenotypes in PKU. Gene 2016; 594:138-143. [PMID: 27620137 DOI: 10.1016/j.gene.2016.09.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 08/29/2016] [Accepted: 09/08/2016] [Indexed: 10/21/2022]
Abstract
Hyperphenylalaninemias (HPAs) are genetic diseases predominantly caused by a wide range of variants in the phenylalanine hydroxylase (PAH) gene. In vitro expression analysis of PAH variants offers the opportunity to elucidate the molecular mechanisms involved in HPAs and to clarify whether a disease-associated variant is genuinely pathogenic, while investigating the severity of a metabolic phenotype, and determining how a variant exerts its deleterious effects on the PAH enzyme. To study the effects of gene variants on PAH activity, we investigated eight variants: c.611A>G (p.Y204C), c.635T>C (p.L212P), c.746T>C (p.L249P), c.745C>T (p.L249F), c.809G>A (p.R270K), c.782G>C (p.R261P), c.587C>A (p.S196Y) and c.1139C>T (p.T380M), associated with different phenotypic groups. Transient expression of mutant full-length cDNAs in COS-7 cells yielded PAH proteins with PAH activity levels between 7% and 51% compared to the wild-type enzyme. With one exception (p.Y204C, which had no significant impact on PAH function), lower PAH activity was associated with a more severe phenotype (e.g. p.L249P with 7% PAH activity, 100% of classic PKU and no BH4 responsiveness), while higher activity correlated with milder phenotypes (e.g. p.T380M with 28% PAH activity, 97% of mild HPA and 83% of BH4 responsiveness). The results of the in vitro residual PAH activity have major implications, both for our understanding of genotype-phenotype correlations, and thereby existing inconsistencies, but also for the elucidation of the molecular basis of tetrahydrobiopterin (BH4) responsiveness.
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Affiliation(s)
- Roberta Trunzo
- Genetica Medica, Dipartimento di Medicina Clinica e Sperimentale, Università degli Studi di Foggia, Italy.
| | - Rosa Santacroce
- Genetica Medica, Dipartimento di Medicina Clinica e Sperimentale, Università degli Studi di Foggia, Italy
| | - Nan Shen
- Dietmar-Hopp Metabolic Center, University Children's Hospital, Department of General Pediatrics, Heidelberg, Germany
| | - Sabine Jung-Klawitter
- Dietmar-Hopp Metabolic Center, University Children's Hospital, Department of General Pediatrics, Heidelberg, Germany
| | - Angelica Leccese
- Genetica Medica, Dipartimento di Medicina Clinica e Sperimentale, Università degli Studi di Foggia, Italy
| | - Giuseppe De Girolamo
- Genetica Medica, Dipartimento di Medicina Clinica e Sperimentale, Università degli Studi di Foggia, Italy
| | - Maurizio Margaglione
- Genetica Medica, Dipartimento di Medicina Clinica e Sperimentale, Università degli Studi di Foggia, Italy
| | - Nenad Blau
- Dietmar-Hopp Metabolic Center, University Children's Hospital, Department of General Pediatrics, Heidelberg, Germany
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The Spectrum of PAH Mutations and Increase of Milder Forms of Phenylketonuria in Sweden During 1965-2014. JIMD Rep 2016; 34:19-26. [PMID: 27469133 DOI: 10.1007/8904_2016_4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 06/20/2016] [Accepted: 06/23/2016] [Indexed: 04/03/2023] Open
Abstract
Newborn screening (NBS) for phenylketonuria (PKU) which has a continuum of disease severities has been performed for more than 50 years. The screening method has undergone a continuous development with not only improvements of the positive predictive value but also identification of milder forms of the disease. With the introduction of genetic testing the confirmation of the diagnosis has improved. The Swedish NBS is centralized to one laboratory, which also performs confirmatory testing.Here we present the results of NBS for PKU in Sweden during 1965-2014 describing an increase in diagnosed patients and a shift in the spectrum of phenylalanine hydroxylase (PAH) mutations towards an increasing heterogeneity. Milder mutations common in southern Europe and the Middle East together with lowering of the recall level for phenylalanine (Phe) have led to a shift towards milder phenotypes among the patients identified by the screening program. The inclusion of a Phe and tyrosine (Tyr) ratio as an additional marker has improved the positive predictive value to the present 0.92. Also discussed is what impact earlier sampling has had on the prediction of disease severity, concluding that the shift of age at sampling from 72 to 48 h does not increase the risk of missing patients in need of treatment.
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Li N, Jia H, Liu Z, Tao J, Chen S, Li X, Deng Y, Jin X, Song J, Zhang L, Liang Y, Wang W, Zhu J. Molecular characterisation of phenylketonuria in a Chinese mainland population using next-generation sequencing. Sci Rep 2015; 5:15769. [PMID: 26503515 PMCID: PMC4621502 DOI: 10.1038/srep15769] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 10/01/2015] [Indexed: 11/28/2022] Open
Abstract
Phenylketonuria (PKU) is an inherited autosomal recessive disorder of phenylalanine metabolism, mainly caused by a deficiency of phenylalanine hydroxylase (PAH). The incidence of various PAH mutations differs among race and ethnicity. Here we report a spectrum of PAH mutations complied from 796 PKU patients from mainland China. The all 13 exons and adjacent intronic regions of the PAH gene were determined by next-generation sequencing. We identified 194 different mutations, of which 41 are not reported before. Several mutations reoccurred with high frequency including p.R243Q, p.EX6-96A > G, p.V399V, p.R241C, p.R111*, p.Y356*, p.R413P, and IVS4-1G > A. 76.33% of mutations were localized in exons 3, 6, 7, 11, 12. We further compared the frequency of each mutation between populations in northern and southern China, and found significant differences in 19 mutations. Furthermore, we identified 101 mutations that are not reported before in Chinese population, our study thus broadens the mutational spectrum of Chinese PKU patients. Additionally, 41 novel mutations will expand and improve PAH mutation database. Finally, our study offers proof that NGS is effective, reduces screening times and costs, and facilitates the provision of appropriate genetic counseling for PKU patients.
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Affiliation(s)
- Nana Li
- National Center for Birth Defect Monitoring, West China Second University Hospital, Sichuan University, Sec. 3 No. 20, South RenMin Road, Chengdu, Sichuan, China.,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, West China Second University Hospital, Sichuan University, Sec. 3 No. 20, South RenMin Road, Chengdu, Sichuan, China
| | - Haitao Jia
- BGI-Shenzhen, Building No. 11, Beishan Industrial Zone, Yantian District, Shenzhen, Guangdong China
| | - Zhen Liu
- National Center for Birth Defect Monitoring, West China Second University Hospital, Sichuan University, Sec. 3 No. 20, South RenMin Road, Chengdu, Sichuan, China.,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, West China Second University Hospital, Sichuan University, Sec. 3 No. 20, South RenMin Road, Chengdu, Sichuan, China
| | - Jing Tao
- National Center for Birth Defect Monitoring, West China Second University Hospital, Sichuan University, Sec. 3 No. 20, South RenMin Road, Chengdu, Sichuan, China.,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, West China Second University Hospital, Sichuan University, Sec. 3 No. 20, South RenMin Road, Chengdu, Sichuan, China
| | - Song Chen
- BGI-Shenzhen, Building No. 11, Beishan Industrial Zone, Yantian District, Shenzhen, Guangdong China
| | - Xiaohong Li
- National Center for Birth Defect Monitoring, West China Second University Hospital, Sichuan University, Sec. 3 No. 20, South RenMin Road, Chengdu, Sichuan, China.,Laboratory of Molecular Epidemiology for birth defect, West China Institute of Women and Children's Health, Sichuan University, Chengdu, China
| | - Ying Deng
- National Center for Birth Defect Monitoring, West China Second University Hospital, Sichuan University, Sec. 3 No. 20, South RenMin Road, Chengdu, Sichuan, China.,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, West China Second University Hospital, Sichuan University, Sec. 3 No. 20, South RenMin Road, Chengdu, Sichuan, China
| | - Xi Jin
- National Center for Birth Defect Monitoring, West China Second University Hospital, Sichuan University, Sec. 3 No. 20, South RenMin Road, Chengdu, Sichuan, China.,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, West China Second University Hospital, Sichuan University, Sec. 3 No. 20, South RenMin Road, Chengdu, Sichuan, China
| | - Jiaping Song
- BGI-Shenzhen, Building No. 11, Beishan Industrial Zone, Yantian District, Shenzhen, Guangdong China
| | - Liangtao Zhang
- BGI-Shenzhen, Building No. 11, Beishan Industrial Zone, Yantian District, Shenzhen, Guangdong China
| | - Yu Liang
- BGI-Shenzhen, Building No. 11, Beishan Industrial Zone, Yantian District, Shenzhen, Guangdong China
| | - Wei Wang
- BGI-Shenzhen, Building No. 11, Beishan Industrial Zone, Yantian District, Shenzhen, Guangdong China
| | - Jun Zhu
- National Center for Birth Defect Monitoring, West China Second University Hospital, Sichuan University, Sec. 3 No. 20, South RenMin Road, Chengdu, Sichuan, China.,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, West China Second University Hospital, Sichuan University, Sec. 3 No. 20, South RenMin Road, Chengdu, Sichuan, China.,Laboratory of Molecular Epidemiology for birth defect, West China Institute of Women and Children's Health, Sichuan University, Chengdu, China
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Chen YF, Jia HT, Chen ZH, Song JP, Liang Y, Pei JJ, Wu ZJ, Wang J, Qiu YL, Liu G, Sun DM, Jiang XY. Mutational spectrum of phenylketonuria in Jiangsu province. Eur J Pediatr 2015; 174:1333-8. [PMID: 25894915 DOI: 10.1007/s00431-015-2539-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 04/01/2015] [Accepted: 04/06/2015] [Indexed: 12/22/2022]
Abstract
UNLABELLED Phenylketonuria (PKU) is caused by variants in the phenylalanine hydroxylase (PAH) gene. We systematically investigated all 13 exons of the PAH gene and their flanking introns in 31 unrelated patients and their parents using next-generation sequencing (NGS). A total of 33 different variants were identified in 58 of 62 mutant PAH alleles. The prevalent variants with a relative frequency of 5 % or more were c.721C > T, c.1068C > A, c.611A > G, c.1197A > T, c.728G > A, c.331C > T, and c.442-1G > A. One novel variant was identified in this study-c.699C > G. We studied genotype-phenotype correlations using the Guldberg arbitrary value (AV) system, which revealed a consistency rate of 38 % (8/21) among the 21 predicted phenotypes. The genotype-based prediction of BH4 responsiveness was also evaluated, and 14 patients (45.2 %) were predicted to be BH4 responsive. CONCLUSION This study presents the spectrum of PAH variants in Jiangsu province. The information obtained from the genotype-based prediction of BH4 responsiveness might be used for the rational selection of candidates for BH4 testing. WHAT IS KNOWN • Phenylketonuria (PKU) is caused by variants in the phenylalanine hydroxylase (PAH) gene. • The spectrum of PAH variants in different Chinese populations has been reported. What is new: • This is the first report on the spectrum of PAH variants in Jiangsu province. • This study identified one novel PAH variant-c.699C>G-and and tries to show a genotype-phenotype relationship also regarding BH4-responsiveness.
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Affiliation(s)
- Ya-fen Chen
- Department of Children Health Care, Wuxi Maternal and Child Health Hospital, No.48 Huaishu Alley, Wuxi, Jiangsu Province, China.
| | - Hai-tao Jia
- Beijing Genomics Institute at Shenzhen, Building No.11, Beishan Industrial Zone, Yantian District, Shenzhen, Guangdong, China.
| | - Zhong-hai Chen
- Beijing Genomics Institute at Shenzhen, Building No.11, Beishan Industrial Zone, Yantian District, Shenzhen, Guangdong, China.
| | - Jia-ping Song
- Beijing Genomics Institute at Shenzhen, Building No.11, Beishan Industrial Zone, Yantian District, Shenzhen, Guangdong, China.
| | - Yu Liang
- Beijing Genomics Institute at Shenzhen, Building No.11, Beishan Industrial Zone, Yantian District, Shenzhen, Guangdong, China.
| | - Jing-jing Pei
- Department of Children Health Care, Wuxi Maternal and Child Health Hospital, No.48 Huaishu Alley, Wuxi, Jiangsu Province, China.
| | - Zhi-jun Wu
- Department of Children Health Care, Wuxi Maternal and Child Health Hospital, No.48 Huaishu Alley, Wuxi, Jiangsu Province, China.
| | - Jing Wang
- Department of Children Health Care, Suqian Maternal and Child Health Hospital, No. 9 Ping-An Road, Suqian, Jiangsu Province, China.
| | - Ya-li Qiu
- Department of Children Health Care, Suqian Maternal and Child Health Hospital, No. 9 Ping-An Road, Suqian, Jiangsu Province, China.
| | - Gang Liu
- Beijing Genomics Institute at Shenzhen, Building No.11, Beishan Industrial Zone, Yantian District, Shenzhen, Guangdong, China.
| | - Dong-mei Sun
- Beijing Genomics Institute at Shenzhen, Building No.11, Beishan Industrial Zone, Yantian District, Shenzhen, Guangdong, China.
| | - Xin-ye Jiang
- Department of Children Health Care, Wuxi Maternal and Child Health Hospital, No.48 Huaishu Alley, Wuxi, Jiangsu Province, China.
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13
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Réblová K, Kulhánek P, Fajkusová L. Computational study of missense mutations in phenylalanine hydroxylase. J Mol Model 2015; 21:70. [PMID: 25750018 DOI: 10.1007/s00894-015-2620-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Accepted: 02/15/2015] [Indexed: 10/23/2022]
Abstract
Hyperphenylalaninemia (HPA) is one of the most common metabolic disorders. HPA, which is transmitted by an autosomal recessive mode of inheritance, is caused by mutations of the phenylalanine hydroxylase gene. Most mutations are missense and lead to reduced protein stability and/or impaired catalytic function. The impact of such mutations varies, ranging from classical phenylketonuria (PKU), mild PKU, to non-PKU HPA phenotypes. Despite the fact that HPA is a monogenic disease, clinical data show that one PKU genotype can be associated with more in vivo phenotypes, which indicates the role of other (still unknown) factors. To better understand the phenotype-genotype relationships, we analyzed computationally the impact of missense mutations in homozygotes stored in the BIOPKU database. A total of 34 selected homozygous genotypes was divided into two main groups according to their phenotypes: (A) genotypes leading to non-PKU HPA or combined phenotype non-PKU HPA/mild PKU and (B) genotypes leading to classical PKU, mild PKU or combined phenotype mild PKU/classical PKU. Combining in silico analysis and molecular dynamics simulations (in total 3 μs) we described the structural impact of the mutations, which allowed us to separate 32 out of 34 mutations between groups A and B. Testing the simulation conditions revealed that the outcome of mutant simulations can be modulated by the ionic strength. We also employed programs SNPs3D, Polyphen-2, and SIFT but based on the predictions performed we were not able to discriminate mutations with mild and severe PKU phenotypes.
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Affiliation(s)
- Kamila Réblová
- Central European Institute of Technology (CEITEC), Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic,
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14
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Groselj U, Tansek MZ, Podkrajsek KT, Battelino T. Mutation analysis in mild hyperphenylalaninemia (HPA) patients — Whom and what to screen? Clin Biochem 2014; 47:236. [DOI: 10.1016/j.clinbiochem.2013.11.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Revised: 10/29/2013] [Accepted: 11/06/2013] [Indexed: 10/26/2022]
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