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Song B, Ma Z, Liu W, Lu L, Jian Y, Yu L, Wan Z, Yue X, Kong Y. Clinical, biochemical and molecular spectrum of mild 6-pyruvoyl-tetrahydropterin synthase deficiency and a case report. Fetal Pediatr Pathol 2021; 40:707-716. [PMID: 32202960 DOI: 10.1080/15513815.2020.1737992] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Background 6-Pyruvoyl-tetrahydropterin synthase (PTS) is the key enzyme in BH4 synthesis. PTS deficiency is classified as severe type and mild type, and the prognosis and treatment differ for these types. Distinguishing between two types in the early stage is difficult. Reference to reported cases is needed for interpretation of the correlation between genotype and prognosis. Case report: We report a full-term female newborn with mild PTS deficiency. On the day 21 after birth, the phenylalanine level was 859.6 mmol/L (reference range: 30-117 mmol/L). After 1 year of observation, the patient was found to be in a healthy condition without treatment. Conclusions: Although the phenylalanine level is high in mild PTS deficiency patients after birth, some of them may have few symptoms with no treatment. We review 19 cases and find 8 mutations of PTS that may be associated with mild PTS deficiency.
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Affiliation(s)
- Boyan Song
- Department of Laboratory Medicine, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing, China
| | - Zhijun Ma
- Department of Laboratory Medicine, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing, China
| | - Wei Liu
- Department of Laboratory Medicine, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing, China
| | - Lihong Lu
- Department of Laboratory Medicine, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing, China
| | - Yongjian Jian
- Department of Laboratory Medicine, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing, China
| | - Lu Yu
- Department of Laboratory Medicine, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing, China
| | - Zhihui Wan
- Department of Laboratory Medicine, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing, China
| | - Xiaofei Yue
- Department of Laboratory Medicine, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing, China
| | - Yuanyuan Kong
- Newborn Screening Center, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing, China
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Long-Term Neurological Outcomes of Adult Patients with Phenylketonuria before and after Newborn Screening in Japan. Int J Neonatal Screen 2021; 7:ijns7020021. [PMID: 33919983 PMCID: PMC8167766 DOI: 10.3390/ijns7020021] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 03/29/2021] [Accepted: 04/12/2021] [Indexed: 11/17/2022] Open
Abstract
Japanese newborn screening (NBS) for phenylketonuria (PKU) was initiated in 1977. We surveyed the neurological outcomes of Japanese adult patients with PKU to investigate the long-term effects and of and issues with NBS. Eighty-five patients with PKU aged over 19 years who continued to be treated with a phenylalanine-free amino acid formula were investigated by administering questionnaires regarding clinical characteristics, such as mental ability, education status, and therapeutic condition. Of the 85 subjects, 68 patients were detected by NBS (NBS group), while the other 17 were clinically diagnosed before the initiation of NBS (pre-NBS group). Further, 10 of the 68 NBS patients presented intellectual and/or psychiatric disabilities, 5 of whom had a history of treatment discontinuation; in contrast, 12 of the 17 pre-NBS patients presented with neuropsychiatric symptoms. Regarding social outcomes, almost all patients in the NBS group could live an independent life, while over half of the patients in the pre-NBS group were not employed or lived in nursing-care facilities. Neurological outcomes are obviously improved by NBS in Japan. However, some patients, even those detected by NBS, developed neuropsychiatric symptoms due to treatment disruption. Lifelong and strict management is essential to maintain good neurological and social prognoses for patients with PKU.
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Ferreira F, Azevedo L, Neiva R, Sousa C, Fonseca H, Marcão A, Rocha H, Carmona C, Ramos S, Bandeira A, Martins E, Campos T, Rodrigues E, Garcia P, Diogo L, Ferreira AC, Sequeira S, Silva F, Rodrigues L, Gaspar A, Janeiro P, Amorim A, Vilarinho L. Phenylketonuria in Portugal: Genotype-phenotype correlations using molecular, biochemical, and haplotypic analyses. Mol Genet Genomic Med 2021; 9:e1559. [PMID: 33465300 PMCID: PMC8104178 DOI: 10.1002/mgg3.1559] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 10/29/2020] [Indexed: 11/12/2022] Open
Abstract
Background The impairment of the hepatic enzyme phenylalanine hydroxylase (PAH) causes elevation of phenylalanine levels in blood and other body fluids resulting in the most common inborn error of amino acid metabolism (phenylketonuria). Persistently high levels of phenylalanine lead to irreversible damage to the nervous system. Therefore, early diagnosis of the affected individuals is important, as it can prevent clinical manifestations of the disease. Methods In this report, the biochemical and genetic findings performed in 223 patients diagnosed through the Portuguese Neonatal Screening Program (PNSP) are presented. Results Overall, the results show that a high overlap exists between different types of variants and phenylalanine levels. Molecular analyses reveal a wide mutational spectrum in our population with a total of 56 previously reported variants, most of them found in compound heterozygosity (74% of the patients). Intragenic polymorphic markers were used to assess the haplotypic structure of mutated chromosomes for the most frequent variants found in homozygosity in our population (p.Ile65Thr, p.Arg158Gln, p.Leu249Phe, p.Arg261Gln, p.Val388Met, and c.1066‐11G>A). Conclusion Our data reveal high heterogeneity at the biochemical and molecular levels and are expected to provide a better understanding of the molecular basis of this disease and to provide clues to elucidate genotype–phenotype correlations.
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Affiliation(s)
- Filipa Ferreira
- Newborn Screening, Metabolic and Genetics Unit, Department of Human Genetics, National Institute of Health Dr Ricardo Jorge, Porto, Portugal
| | - Luísa Azevedo
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,IPATIMUP - Instituto de Patologia e Imunologia Molecular da Universidade do Porto, Porto, Portugal.,FCUP - Faculty of Sciences, University of Porto, Porto, Portugal
| | - Raquel Neiva
- Newborn Screening, Metabolic and Genetics Unit, Department of Human Genetics, National Institute of Health Dr Ricardo Jorge, Porto, Portugal
| | - Carmen Sousa
- Newborn Screening, Metabolic and Genetics Unit, Department of Human Genetics, National Institute of Health Dr Ricardo Jorge, Porto, Portugal
| | - Helena Fonseca
- Newborn Screening, Metabolic and Genetics Unit, Department of Human Genetics, National Institute of Health Dr Ricardo Jorge, Porto, Portugal
| | - Ana Marcão
- Newborn Screening, Metabolic and Genetics Unit, Department of Human Genetics, National Institute of Health Dr Ricardo Jorge, Porto, Portugal
| | - Hugo Rocha
- Newborn Screening, Metabolic and Genetics Unit, Department of Human Genetics, National Institute of Health Dr Ricardo Jorge, Porto, Portugal
| | - Célia Carmona
- Newborn Screening, Metabolic and Genetics Unit, Department of Human Genetics, National Institute of Health Dr Ricardo Jorge, Porto, Portugal
| | - Sónia Ramos
- Newborn Screening, Metabolic and Genetics Unit, Department of Human Genetics, National Institute of Health Dr Ricardo Jorge, Porto, Portugal
| | - Anabela Bandeira
- Inherited Metabolic Disease Reference Center, Pediatric Department, Centro Hospitalar Universitário do Porto, Porto, Portugal
| | - Esmeralda Martins
- Inherited Metabolic Disease Reference Center, Pediatric Department, Centro Hospitalar Universitário do Porto, Porto, Portugal
| | - Teresa Campos
- Metabolic Diseases Unit, Pediatric Department, University Center São João Hospital - HSJ, Porto, Portugal
| | - Esmeralda Rodrigues
- Metabolic Diseases Unit, Pediatric Department, University Center São João Hospital - HSJ, Porto, Portugal
| | - Paula Garcia
- Inherited Metabolic Disease Reference Center, Pediatric Hospital, Hospital and University Center of Coimbra, Coimbra, Portugal
| | - Luísa Diogo
- Inherited Metabolic Disease Reference Center, Pediatric Hospital, Hospital and University Center of Coimbra, Coimbra, Portugal
| | - Ana Cristina Ferreira
- Metabolic Unit, Hospital Dona Estefânia, Centro Hospitalar Universitário Lisboa Central, Lisbon, Portugal
| | - Silvia Sequeira
- Metabolic Unit, Hospital Dona Estefânia, Centro Hospitalar Universitário Lisboa Central, Lisbon, Portugal
| | - Francisco Silva
- Pediatric Department, Hospital Central of Funchal, Funchal, Portugal
| | - Luísa Rodrigues
- Pediatrics Department, Hospital of Divino Espírito Santo of Ponta Delgada, EPE, Ponta Delgada, Azores, Portugal
| | - Ana Gaspar
- Inherited Metabolic Disease Reference Center, Lisbon North University Hospital Center (CHULN), EPE, Lisboa, Portugal
| | - Patrícia Janeiro
- Inherited Metabolic Disease Reference Center, Lisbon North University Hospital Center (CHULN), EPE, Lisboa, Portugal
| | - António Amorim
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,IPATIMUP - Instituto de Patologia e Imunologia Molecular da Universidade do Porto, Porto, Portugal.,FCUP - Faculty of Sciences, University of Porto, Porto, Portugal
| | - Laura Vilarinho
- Newborn Screening, Metabolic and Genetics Unit, Department of Human Genetics, National Institute of Health Dr Ricardo Jorge, Porto, Portugal.,Research and Development Unit, Department of Human Genetics, National Institute of Health Dr Ricardo Jorge, Porto, Portugal
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Gouda AS, Nazim WS. Development of a simple method for the analysis of phenylalanine in dried blood spot using tandem mass spectrometry. EGYPTIAN JOURNAL OF MEDICAL HUMAN GENETICS 2020. [DOI: 10.1186/s43042-020-00100-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Phenylketonuria (PKU), inborn error of metabolism, results from phenylalanine hydroxylase deficiency. PKU leads to neurological manifestations, intellectual disability, and mental disorders. Treatment depends on phenylalanine-restricted diet.
Diagnosis and follow-up of PKU depends on blood phenylalanine level. The development of bacterial inhibition assay was the first routine screening test for PKU. ELISA and amino acids analyzers methods were then developed.
Tandem mass spectrometry was introduced for newborn screening from dried blood spot in the late 1990s. Since then, several methods were developed, starting from using HPLC column followed by direct injection in mass spectrometer by analyte derivatization and use of external and internal standards. Kits are available for neonatal screening without derivatization using internal standards for quantitation.
Due to high PKU incidence in Egypt, it is important to continuously ameliorate the methods for neonatal diagnosis and follow-up.
Results
External standards as dried blood spots were prepared according to the previously described procedures. These standards were evaluated for phenylalanine concentration using ELISA kit. Analysis of samples was done with a single-step elution from dried blood spot followed by 1-min mass spectrometry analysis. Validation was done according to US FDA and other related guidelines. Fifty samples were analyzed by ELISA and another 126 samples were analyzed by mass spectrometer kit. All these samples were analyzed by the developed method and no statistically significant difference was observed.
Conclusion
New simple method is developed for phenylalanine quantitation in dried blood spot using tandem mass spectrometry. This method is cost and time effective.
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Muntau AC, du Moulin M, Feillet F. Diagnostic and therapeutic recommendations for the treatment of hyperphenylalaninemia in patients 0-4 years of age. Orphanet J Rare Dis 2018; 13:173. [PMID: 30268140 PMCID: PMC6162894 DOI: 10.1186/s13023-018-0911-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 09/12/2018] [Indexed: 12/17/2023] Open
Abstract
BACKGROUND Treatment of phenylketonuria (PKU) with sapropterin dihydrochloride in responsive patients from an early age can have many advantages for the patient over dietary restriction alone. Accordingly, approval of sapropterin in the European Union was extended in 2015 to include patients aged 0-4 years, bringing the treatment age range in line with that in the USA and providing an additional treatment option for those patients with PKU who are responsive or partially responsive to treatment with sapropterin. Subsequently, European guidelines have been published on the diagnosis and management of patients with PKU. However, testing for PKU can be demanding and requires particular expertise. We have compiled experience-based, real-world guidance in an algorithmic format to complement the published guidelines, with the overall aim to achieve optimized and individualized care for patients with PKU. RESULTS Our guidance covers aspects such as how to perform, monitor and interpret appropriate biochemical measures to achieve effective patient management and desired outcomes, how to perform a tetrahydrobiopterin (BH4) loading test to assess responsiveness in newborns, and how to initiate sapropterin treatment in patients from birth. We also provide our expert opinion on starting pharmacotherapy in patients who were previously managed by diet alone. CONCLUSIONS Real-world-based guidance is particularly important in managing therapeutic strategies in newborns with PKU to achieve optimal long-term outcomes and will serve as a complement to the other published guidelines.
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Affiliation(s)
- Ania C. Muntau
- University Children’s Hospital, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Marcel du Moulin
- University Children’s Hospital, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Francois Feillet
- Department of Pediatrics, Hôpital d’Enfants Brabois, CHU Nancy, Vandoeuvre les Nancy, France
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6
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Acute care utilization for inherited metabolic diseases among children identified through newborn screening in New York state. Genet Med 2014; 16:665-70. [DOI: 10.1038/gim.2014.21] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Accepted: 02/06/2014] [Indexed: 11/08/2022] Open
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7
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Douglas TD, Ramakrishnan U, Kable JA, Singh RH. Longitudinal quality of life analysis in a phenylketonuria cohort provided sapropterin dihydrochloride. Health Qual Life Outcomes 2013; 11:218. [PMID: 24373161 PMCID: PMC3880979 DOI: 10.1186/1477-7525-11-218] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Accepted: 12/20/2013] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Sapropterin dihydrochloride effectively lowers plasma phenylalanine (Phe) for at least a third of phenylketonuria (PKU) patients, with potential for increased dietary Phe tolerance and decreased medical food requirement. OBJECTIVE To investigate long-term quality of life (QOL) in patients with phenylketonuria (PKU) who took sapropterin (BH4, Kuvan®) for up to one year. METHODS 37 PKU patients, ages 10-49 years, were asked to complete a PKU-specific self-report QOL questionnaire (QOLQ) at baseline, 1, 4, 8, and 12 months. Questions were scored on a 5-point Likert scale under 5 sub-sections measuring Impact, Worries, Satisfaction, Support, and General wellbeing in relation to PKU. Responders with a plasma Phe decrease ≥ 15% after 1 month on sapropterin remained on the drug; Nonresponders ceased sapropterin after the trial month. Responders able to relax medical diet and maintain plasma Phe control were classified as Definitive; Responders unable to relax medical diet were classified as Provisional. All patients were routinely monitored by a registered dietitian. Data was analyzed in SPSS 19.0 using regression techniques. RESULTS Of 17 Responders, 11 could maintain adequate Phe control on a less restrictive diet. One year mean Impact sub-score trends improved significantly for all sapropterin response groups, with greatest improvement among Definitive Responders (p < 0.0001). Satisfaction sub-scores also improved for Definitive Responders (p = 0.001). Trends for Total QOL score improved significantly over time for both Definitive (p = 0.001) and Provisional Responders (p = 0.028). Improvements in Definitive Responder scores were associated with increased Phe tolerance (Impact: p < 0.0001, Satisfaction: p = 0.022, Total QOL: p = 0.005) and MF adjustment (Satisfaction: p = 0.014, Total QOL: p = 0.026). Other sub-section scores remained steady, unaffected by sapropterin response or diet modification. CONCLUSION Increased Phe tolerance and reduced MF requirement in sapropterin Definitive Responders improves QOL perception across one year, specifically for life impact and satisfaction.
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Affiliation(s)
- Teresa D Douglas
- Metabolic Nutrition Program, Division of Medical Genetics, Emory Department of Human Genetics, 2165 North Decatur Road, Decatur, GA 30033, USA
- Nutrition and Health Sciences Program, Division of Biological and Biomedical Sciences, Laney Graduate School, Emory University, Atlanta, GA USA
| | - Usha Ramakrishnan
- Hubert Department of Global Health, Emory University Rollins School of Public Health, 1518 Clifton Road NE. Room 7009, Atlanta, GA 30322, USA
| | - Julie A Kable
- Fetal Alcohol Syndrome and Drug Exposure Center, Marcus Autism Center, 1920 Briarcliff Road, Atlanta, GA 30329, USA
- Division of Autism and Related Disorders, Department of Pediatrics, Emory University School of Medicine, Atlanta GA, USA
| | - Rani H Singh
- Metabolic Nutrition Program, Division of Medical Genetics, Emory Department of Human Genetics, 2165 North Decatur Road, Decatur, GA 30033, USA
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Mei L, Song P, Kokudo N, Xu L, Tang W. Current situation and prospects of newborn screening and treatment for Phenylketonuria in China - compared with the current situation in the United States, UK and Japan. Intractable Rare Dis Res 2013; 2:106-14. [PMID: 25343113 PMCID: PMC4204557 DOI: 10.5582/irdr.2013.v2.4.106] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Accepted: 11/30/2013] [Indexed: 12/16/2022] Open
Abstract
Phenylketonuria (PKU) is a treat-able and prevent-able inborn error of metabolism which leads to severe mental retardation and neurobehavioral abnormalities. A screening program, especially for early detection, combined with a Phe-restricted therapeutic diet can help to control the process of PKU of most patients. The China government has put more emphasis on newborn screening and treatment against PKU, yet by comparing the situation of newborn screening and treatment against PKU in China and the relatively developed countries - United States, United Kingdom and Japan, the newborn screening and treatment against PKU in China is relatively weak and many deficiencies are found. More studies concerning multi-stage target blood Phe concentration criteria, a policy that requires newborn screening has to be taken, better financial support for newborn screening, publicity for newborn screening, and national guidelines for treatment of PKU may be prospects in China and may provide some support for better development of newborn screening and treatment against PKU in China.
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Affiliation(s)
- Lin Mei
- Department of Health Care Management and Maternal and Child Health, Shandong University, Ji'nan, Shandong, China
- Department of Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Peipei Song
- Department of Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Norihiro Kokudo
- Department of Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Lingzhong Xu
- Department of Health Care Management and Maternal and Child Health, Shandong University, Ji'nan, Shandong, China
- Address correspondence to: Dr. Lingzhong Xu, Department of Health Care Management and Maternal and Child Health, NO.110 mailbox, Shandong University, 44 Wenhuaxi Road, Ji'nan 250012, China. E-mail:
| | - Wei Tang
- Department of Health Care Management and Maternal and Child Health, Shandong University, Ji'nan, Shandong, China
- Department of Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- Dr. Wei Tang, Department of Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan. E-mail:
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Long-term follow-up of children with confirmed newborn screening disorders using record linkage. Genet Med 2012; 13:881-6. [PMID: 21637103 DOI: 10.1097/gim.0b013e31821e485b] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
BACKGROUND Long-term follow-up of children identified through newborn screening is a critical process of data collection and analysis for advancing the public health understanding of the health outcomes and service uptake of the affected children. This article describes first steps toward the long-term follow-up of newborn screening children with confirmed disorders through records linkage using population-based administrative data. METHODS The study cohort consisted of children born in 2006-2007 with confirmed disorders identified through newborn screening. Deterministic data linkage methods were used for record matching. RESULTS The cohort was followed up to 2 years after birth by matching to data sources including vital records, hospital discharges, the Congenital Malformations Registry, and Early Intervention to monitor service utilization, comorbidities, and mortality of the affected children. Of 1215 children with confirmed conditions identified through newborn screening, 25 deaths (2.1%) were identified, 86.1% used hospital (in- or outpatient) services, 36.1% were enrolled in the Congenital Malformations Registry, and 19.9% used the services of the Early Intervention program during the 2-year follow-up period. CONCLUSIONS Long-term follow-up of children with disorders identified through newborn screening can be initiated by using existing administrative data. This method is an inexpensive, cost-effective. and efficient approach for periodical assessment of services utilization, the efficiency of service delivery, and health outcomes for affected individuals.
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Chiu YH, Chang YC, Chang YH, Niu DM, Yang YL, Ye J, Jiang J, Okano Y, Lee DH, Pangkanon S, Kuptanon C, Hock NL, Chiong MA, Cavan BV, Hsiao KJ, Liu TT. Mutation spectrum of and founder effects affecting the PTS gene in East Asian populations. J Hum Genet 2012; 57:145-52. [DOI: 10.1038/jhg.2011.146] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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11
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Lee WT. Disorders of amino acid metabolism associated with epilepsy. Brain Dev 2011; 33:745-52. [PMID: 21803516 DOI: 10.1016/j.braindev.2011.06.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2011] [Revised: 06/29/2011] [Accepted: 06/30/2011] [Indexed: 10/18/2022]
Abstract
Seizures are a common presenting manifestation in children with disorders of amino acid metabolism. However, seizures may be very common in some specific diseases, but are rare in other diseases. In patients with classical maple syrup urine disease (MSUD), seizures commonly occur in the neonatal stage. But in intermittent or intermediate MSUD, seizures may develop in a later stage, or are uncommon. Patients with nonketotic hyperglycinemia often present with early myoclonic encephalopathy in the first weeks of life. However, in patients with atypical variants, seizures may be rare. In addition, patients with sulfite oxidase deficiency, serine deficiency, or GABA-related disorders may also present with different types of seizures. In monoamine biosynthesis disorders, seizures are rare, but paroxysmal dystonia is frequently misdiagnosed as seizures. Therefore, the incidence of seizures in disorders of amino acid metabolism is variable. Timely diagnosis and early treatment may improve the prognosis of these disorders.
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Affiliation(s)
- Wang-Tso Lee
- Department of Pediatrics, National Taiwan University Hospital, Taipei.
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12
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Koura HM, Abdallah Ismail N, Kamel AF, Ahmed AM, Saad-Hussein A, Effat LK. A long-term study of bone mineral density in patients with phenylketonuria under diet therapy. Arch Med Sci 2011; 7:493-500. [PMID: 22295034 PMCID: PMC3258737 DOI: 10.5114/aoms.2011.23417] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2010] [Revised: 11/10/2010] [Accepted: 12/05/2010] [Indexed: 11/17/2022] Open
Abstract
INTRODUCTION Dietary control of classic phenylketonuria (PKU) needs restriction of natural proteins; adequate protein intake is achieved by adding low phenylalanine (phe) formulae. The adequacy of this diet for normal bone mineralization had not been sufficiently evaluated. Our aim was to evaluate and follow up bone mineral density (BMD) in children and adolescents with PKU within a 2-year time interval to assess the adequacy of a phenylalanine restricted diet for bone mineralization and to search for a possible relationship between BMD, dietary control and blood phenylalanine (phe) concentrations. MATERIAL AND METHODS Thirty-two patients with classic PKU (3-19 years) were evaluated for their bone mineral status using dual energy X-ray absorptiometry (DEXA) both at the beginning (baseline) and the end (follow-up) of the study. RESULTS Low BMD was detected in 31.25% at the start and in 6.25% of patients after 2 years follows-up. No relationship was found between BMD and the duration of diet compliance and phe level as well. CONCLUSIONS In this study the low BMD detected in our patients was both at baseline and follow-up independent of diet restriction. A yearly DEXA would be highly beneficial for early detection and treatment, thus preventing osteoporosis and decreasing the risk of fractures. We also suggest the importance of searching for new emerging therapies such as enzyme substitution or gene therapy as low protein diet compliance was not enough to maintain normal bone mineral density.
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Affiliation(s)
- Hala M. Koura
- Department of Pediatric, National Research Centre, Cairo, Egypt
| | | | - Ashraf F. Kamel
- Department of Pediatric, National Research Centre, Cairo, Egypt
| | - Azza M Ahmed
- Department of Pediatric, National Research Centre, Cairo, Egypt
| | - Amal Saad-Hussein
- Department of Environmental Research, National Research Centre, Cairo, Egypt
| | - Laila K. Effat
- Department of Molecular Genetic, National Research Centre, Cairo, Egypt
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Kostandyan N, Britschgi C, Matevosyan A, Oganezova A, Davtyan A, Blau N, Steinmann B, Thöny B. The spectrum of phenylketonuria genotypes in the Armenian population: identification of three novel mutant PAH alleles. Mol Genet Metab 2011; 104 Suppl:S93-6. [PMID: 21890392 DOI: 10.1016/j.ymgme.2011.08.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Revised: 08/09/2011] [Accepted: 08/09/2011] [Indexed: 11/22/2022]
Abstract
We present the spectrum of phenylalanine hydroxylase (PAH) gene mutations upon investigating 35 index patients identified with hyperphenylalaninemia in Armenia. One patient was diagnosed with dihydropteridine reductase (DHPR) deficiency, whereas all other 34 and their 6 affected siblings presented with mild or classical phenylketonuria (PKU). By analyzing all 13 exons plus exon-intron boundaries of the PAH gene, we identified two mutant alleles in 23 PKU patients, three mutations in 1, only one mutation in 5, and no mutation in 5 PKU patients. The most prevalent mutation was the well defined splicing error in intron 10, c.1066-11G>A (17/68 alleles). The three alterations, c.836C>T (p.Pro279Leu) in exon 7, c.1129T>G (p.Tyr377Asp) in exon 11, and c.1244A>T (p.Asp415Val) in exon 12, have not been reported in the PAH locus database (http://www.pahdb.mcgill.ca) and, thus, might be specific for the culturally homogenous Armenian population.
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Affiliation(s)
- Natella Kostandyan
- Republic Center of Medical Genetics, Yerevan State Medical University, Armenia
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14
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Abstract
Phenylketonuria is the most prevalent disorder caused by an inborn error in aminoacid metabolism. It results from mutations in the phenylalanine hydroxylase gene. Phenotypes can vary from a very mild increase in blood phenylalanine concentrations to a severe classic phenotype with pronounced hyperphenylalaninaemia, which, if untreated, results in profound and irreversible mental disability. Neonatal screening programmes identify individuals with phenylketonuria. The initiation of a phenylalanine-restricted diet very soon after birth prevents most of the neuropsychological complications. However, the diet is difficult to maintain and compliance is often poor, especially in adolescents, young adults, and pregnant women. Tetrahydrobiopterin stimulates phenylalanine hydroxylase activity in about 20% of patients, and in those patients serves as a useful adjunct to the phenylalanine-restricted diet because it increases phenylalanine tolerance and allows some dietary freedom. Possible future treatments include enzyme substitution with phenylalanine ammonia lyase, which degrades phenylalanine, and gene therapy to restore phenylalanine hydroxylase activity.
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Affiliation(s)
- Nenad Blau
- Division of Clinical Chemistry and Biochemistry, University Children's Hospital, Zurich, Switzerland.
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Marsden DL. Commentary on a Delphi clinical practice protocol for the diagnosis and management of very long chain acyl-CoA dehydrogenase deficiency by Arnold et al. Mol Genet Metab 2009; 96:81-2. [PMID: 19081279 DOI: 10.1016/j.ymgme.2008.10.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2008] [Accepted: 10/16/2008] [Indexed: 11/28/2022]
Abstract
Very long chain acyl-CoA dehydrogenase deficiency (VLCAD) can now be detected by newborn screening by tandem mass spectrometry. The incidence is higher than previously estimated because of the identification of potentially milder later onset variants by screening. Although there is little information in the literature on the optimal management of rare inborn errors, there is a need for management guidelines, especially for non-specialist providers in the community. In the accompanying article, Arnold et al. present a diagnostic and management guideline for VLCAD, developed by the Delphi method for gaining consensus from a panel of 14 metabolic specialists. While consensus was gained for some issues, there was no clear consensus for several important management issues, particularly for the later onset variants. Clearly, there is an urgent need for multinational collaborative protocol driven outcomes studies that will provide the data necessary to establish robust guidelines for inborn errors of metabolism.
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