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van Wegberg AMJ, MacDonald A, Ahring K, Bélanger-Quintana A, Blau N, Bosch AM, Burlina A, Campistol J, Feillet F, Giżewska M, Huijbregts SC, Kearney S, Leuzzi V, Maillot F, Muntau AC, van Rijn M, Trefz F, Walter JH, van Spronsen FJ. The complete European guidelines on phenylketonuria: diagnosis and treatment. Orphanet J Rare Dis 2017; 12:162. [PMID: 29025426 PMCID: PMC5639803 DOI: 10.1186/s13023-017-0685-2] [Citation(s) in RCA: 421] [Impact Index Per Article: 60.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 07/11/2017] [Indexed: 12/22/2022] Open
Abstract
Phenylketonuria (PKU) is an autosomal recessive inborn error of phenylalanine metabolism caused by deficiency in the enzyme phenylalanine hydroxylase that converts phenylalanine into tyrosine. If left untreated, PKU results in increased phenylalanine concentrations in blood and brain, which cause severe intellectual disability, epilepsy and behavioural problems. PKU management differs widely across Europe and therefore these guidelines have been developed aiming to optimize and standardize PKU care. Professionals from 10 different European countries developed the guidelines according to the AGREE (Appraisal of Guidelines for Research and Evaluation) method. Literature search, critical appraisal and evidence grading were conducted according to the SIGN (Scottish Intercollegiate Guidelines Network) method. The Delphi-method was used when there was no or little evidence available. External consultants reviewed the guidelines. Using these methods 70 statements were formulated based on the highest quality evidence available. The level of evidence of most recommendations is C or D. Although study designs and patient numbers are sub-optimal, many statements are convincing, important and relevant. In addition, knowledge gaps are identified which require further research in order to direct better care for the future.
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Affiliation(s)
- A. M. J. van Wegberg
- Division of Metabolic Diseases, Beatrix Children’s Hospital, University Medical Center Groningen, PO BOX 30.001, 9700 RB Groningen, The Netherlands
| | - A. MacDonald
- Dietetic Department, Birmingham Children’s Hospital, Birmingham, UK
| | - K. Ahring
- Department of PKU, Kennedy Centre, Glostrup, Denmark
| | - A. Bélanger-Quintana
- Metabolic Diseases Unit, Department of Paediatrics, Hospital Ramon y Cajal Madrid, Madrid, Spain
| | - N. Blau
- University Children’s Hospital, Dietmar-Hoppe Metabolic Centre, Heidelberg, Germany
- University Children’s Hospital Zürich, Zürich, Switzerland
| | - A. M. Bosch
- Department of Paediatrics, Division of Metabolic Disorders, Academic Medical Centre, University Hospital of Amsterdam, Amsterdam, The Netherlands
| | - A. Burlina
- Division of Inherited Metabolic Diseases, Department of Paediatrics, University Hospital of Padova, Padova, Italy
| | - J. Campistol
- Neuropaediatrics Department, Hospital Sant Joan de Déu, Universitat de Barcelona, Barcelona, Spain
| | - F. Feillet
- Department of Paediatrics, Hôpital d’Enfants Brabois, CHU Nancy, Vandoeuvre les Nancy, France
| | - M. Giżewska
- Department of Paediatrics, Endocrinology, Diabetology, Metabolic Diseases and Cardiology of the Developmental Age, Pomeranian Medical University, Szczecin, Poland
| | - S. C. Huijbregts
- Department of Clinical Child and Adolescent Studies-Neurodevelopmental Disorders, Faculty of Social Sciences, Leiden University, Leiden, The Netherlands
| | - S. Kearney
- Clinical Psychology Department, Birmingham Children’s Hospital, Birmingham, UK
| | - V. Leuzzi
- Department of Paediatrics, Child Neurology and Psychiatry, Sapienza University of Rome, Via dei Sabelli 108, 00185 Rome, Italy
| | - F. Maillot
- CHRU de Tours, Université François Rabelais, INSERM U1069, Tours, France
| | - A. C. Muntau
- University Children’s Hospital, University Medical Centre Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - M. van Rijn
- Division of Metabolic Diseases, Beatrix Children’s Hospital, University Medical Center Groningen, PO BOX 30.001, 9700 RB Groningen, The Netherlands
| | - F. Trefz
- Department of Paediatrics, University of Heidelberg, Heidelberg, Germany
| | - J. H. Walter
- Medicine, Manchester Academic Health Sciences Centre, Central Manchester University Hospitals NHS Foundation Trust, Manchester, UK
| | - F. J. van Spronsen
- Division of Metabolic Diseases, Beatrix Children’s Hospital, University Medical Center Groningen, PO BOX 30.001, 9700 RB Groningen, The Netherlands
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Aldámiz-Echevarría L, Bueno MA, Couce ML, Lage S, Dalmau J, Vitoria I, Llarena M, Andrade F, Blasco J, Alcalde C, Gil D, García MC, González-Lamuño D, Ruiz M, Ruiz MA, Peña-Quintana L, González D, Sánchez-Valverde F. 6R-tetrahydrobiopterin treated PKU patients below 4 years of age: Physical outcomes, nutrition and genotype. Mol Genet Metab 2015; 115:10-6. [PMID: 25882749 DOI: 10.1016/j.ymgme.2015.03.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 03/24/2015] [Accepted: 03/24/2015] [Indexed: 11/21/2022]
Abstract
BACKGROUND AND AIMS Phenylalanine-restricted diets have proven effective in treating phenylketonuria. However, such diets have occasionally been reported to hinder normal development. Our study aimed to assess whether treating 0-4-year-old phenylketonuric patients with 6R-tetrahydrobiopterin might prevent growth retardation later in life. METHODS We conducted a longitudinal retrospective study which examined anthropometric characteristics of phenylketonuric patients on 6R-tetrahydrobiopterin therapy (22 subjects), and compared them with a group of phenylketonuric patients on protein-restricted diets (44 subjects). Nutritional issues were also considered. We further explored possible relationships between mutations in the PAH gene, BH4 responsiveness and growth outcome. RESULTS No significant growth improvements were observed in either the group on 6R-tetrahydrobiopterin treatment (height Z-score: initial= -0.57 ± 1.54; final=-0.52 ± 1.29; BMI Z-score: initial=0.17 ± 1.05; final=0.18 ± 1.00) or the diet-only group (height Z-score: initial=-0.92 ± 0.96; final= -0.78 ± 1.08; BMI Z-score: initial=0.17 ± 0.97; final=-0.07 ± 1.03) over the 1-year observation period. Furthermore, we found no significant differences (p>0.05) between the two groups at any of the time points considered (0, 6 and 12 months). Patients on 6R-tetrahydrobiopterin increased their phenylalanine intake (from 49.1 [25.6-60.3] to 56.5 [39.8-68.3] mgkg(-1)day(-1)) and natural protein intake (from 1.0 [0.8-1.7] to 1.5 [1.0-1.8] g kg(-1)day(-1)), and some patients managed to adopt normal diets. Higher phenylalanine and natural protein intakes were positively correlated with better physical outcomes in the diet-only group (p<0.05). No correlation was found between patient genotype and physical outcomes, results being similar regardless of the nutritional approach used. We did not detect any side effects due to 6R-tetrahydrobiopterin administration. CONCLUSIONS Our study indicates that treating 0-4-year-old phenylketonuric patients with 6R-tetrahydrobiopterin is safe. However, poor developmental outcomes were observed, despite increasing the intake of natural proteins. Genotype could be a valid predictor of tetrahydrobiopterin-responsiveness, since patients who carried the same genotype responded similarly to the 6R-tetrahydrobiopterin loading test. On the other hand, harbouring 6R-tetrahydrobiopterin responsive genotypes did not predispose patients to better physical outcomes.
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Affiliation(s)
- Luis Aldámiz-Echevarría
- Division of Metabolism, BioCruces Health Research Institute, CIBER de Enfermedades Raras (CIBERER), Plaza de Cruces 12, 48903, Barakaldo, Spain.
| | - María A Bueno
- Metabolic Disorders, Dietetics and Nutrition Unit, Virgen del Rocío University Hospital, Manuel Siurot Avenue s/n, 41013, Sevilla, Spain.
| | - María L Couce
- Unit of Diagnosis and Treatment of Congenital Metabolic Diseases, Neonatology Service, Department of Pediatrics. Hospital Clinico Universitario de Santiago de Compostela, CIBER de Enfermedades Raras (CIBERER), IDIS, Spain.
| | - Sergio Lage
- Division of Metabolism, BioCruces Health Research Institute, CIBER de Enfermedades Raras (CIBERER), Plaza de Cruces 12, 48903, Barakaldo, Spain.
| | - Jaime Dalmau
- Nutrition and Metabolopathologies Unit, La Fe University Hospital, Bulevar Sur s/n, 46026, Valencia, Spain.
| | - Isidro Vitoria
- Nutrition and Metabolopathologies Unit, La Fe University Hospital, Bulevar Sur s/n, 46026, Valencia, Spain.
| | - Marta Llarena
- Division of Metabolism, BioCruces Health Research Institute, CIBER de Enfermedades Raras (CIBERER), Plaza de Cruces 12, 48903, Barakaldo, Spain.
| | - Fernando Andrade
- Division of Metabolism, BioCruces Health Research Institute, CIBER de Enfermedades Raras (CIBERER), Plaza de Cruces 12, 48903, Barakaldo, Spain.
| | - Javier Blasco
- Gastroenterology, Hepatology and Child Nutrition Unit, Carlos Haya University Hospital, Avda. Arroyo de los Ángeles s/n, 29011, Málaga, Spain.
| | - Carlos Alcalde
- Paediatrics Unit, Río Hortega University Hospital, Calle Dulzaina 2, 47012, Valladolid, Spain.
| | - David Gil
- Gastroenterology Unit, Virgen de la Arrixaca University Hospital, Ctra. Madrid-Cartagena s/n, El Palmar, 30120, Murcia, Spain.
| | - María C García
- Metabolic Pathologies Unit, Miguel Servet University Hospital, Paseo de Isabel La Católica 1-3, 50009, Zaragoza, Spain.
| | - Domingo González-Lamuño
- Nephrology and Metabolism Unit, Marqués de Valdecilla University Hospital, Avda. Valdecilla 25, 39008, Santander, Spain.
| | - Mónica Ruiz
- Paediatrics Unit, Nuestra Señora de la Candelaria University Hospital, Carretera del Rosario 145, 38010, Santa Cruz de Tenerife, Spain.
| | - María A Ruiz
- Metabolic Pathologies and Neuropaediatrics Unit, Son Espases University Hospital, Carretera de Valldemossa 79, 07120, Palma de Mallorca, Spain.
| | - Luis Peña-Quintana
- Paediatric Gastroenterology, Hepatology and Nutrition Unit, Mother and Child Hospital Complex, Avda. Marítima del Sur s/n, 35016, Las Palmas de Gran Canaria, Spain.
| | - David González
- Metabolic Pathologies Unit, Maternal and Child Hospital, Calle de la Violeta 1, 06010, Badajoz, Spain.
| | - Felix Sánchez-Valverde
- Gastroenterology and Paediatric Nutrition Unit, Virgen del Camino Hospital, C/ De Irunlarrea 4, 31008, Pamplona, Spain.
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Okusaga O, Muravitskaja O, Fuchs D, Ashraf A, Hinman S, Giegling I, Hartmann AM, Konte B, Friedl M, Schiffman J, Hong E, Reeves G, Groer M, Dantzer R, Rujescu D, Postolache TT. Elevated levels of plasma phenylalanine in schizophrenia: a guanosine triphosphate cyclohydrolase-1 metabolic pathway abnormality? PLoS One 2014; 9:e85945. [PMID: 24465804 PMCID: PMC3897774 DOI: 10.1371/journal.pone.0085945] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Accepted: 12/04/2013] [Indexed: 02/07/2023] Open
Abstract
Background Phenylalanine and tyrosine are precursor amino acids required for the synthesis of dopamine, the main neurotransmitter implicated in the neurobiology of schizophrenia. Inflammation, increasingly implicated in schizophrenia, can impair the function of the enzyme Phenylalanine hydroxylase (PAH; which catalyzes the conversion of phenylalanine to tyrosine) and thus lead to elevated phenylalanine levels and reduced tyrosine levels. This study aimed to compare phenylalanine, tyrosine, and their ratio (a proxy for PAH function) in a relatively large sample of schizophrenia patients and healthy controls. Methods We measured non-fasting plasma phenylalanine and tyrosine in 950 schizophrenia patients and 1000 healthy controls. We carried out multivariate analyses to compare log transformed phenylalanine, tyrosine, and phenylalanine:tyrosine ratio between patients and controls. Results Compared to controls, schizophrenia patients had higher phenylalanine (p<0.0001) and phenylalanine: tyrosine ratio (p<0.0001) but tyrosine did not differ between the two groups (p = 0.596). Conclusions Elevated phenylalanine and phenylalanine:tyrosine ratio in the blood of schizophrenia patients have to be replicated in longitudinal studies. The results may relate to an abnormal PAH function in schizophrenia that could become a target for novel preventative and interventional approaches.
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Affiliation(s)
- Olaoluwa Okusaga
- Mood and Anxiety Program, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Department of Psychiatry and Behavioral Sciences, The University of Texas Health Science Center at Houston, Houston, Texas, United States of America
| | - Olesja Muravitskaja
- Mood and Anxiety Program, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Dietmar Fuchs
- Division of Biological Chemistry, Biocenter Innsbruck Medical University, Innsbruck, Austria
| | - Ayesha Ashraf
- Mood and Anxiety Program, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Sarah Hinman
- Mood and Anxiety Program, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Ina Giegling
- Section of Molecular and Clinical Neurobiology, Ludwig Maximilians University, Munich, Germany
| | - Annette M. Hartmann
- Section of Molecular and Clinical Neurobiology, Ludwig Maximilians University, Munich, Germany
| | - Bettina Konte
- Section of Molecular and Clinical Neurobiology, Ludwig Maximilians University, Munich, Germany
| | - Marion Friedl
- Section of Molecular and Clinical Neurobiology, Ludwig Maximilians University, Munich, Germany
| | - Jason Schiffman
- Department of Psychology, University of Maryland, Baltimore, Maryland, United States of America
| | - Elliot Hong
- Maryland Psychiatric Research Center (MPRC), Department of Psychiatry, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Gloria Reeves
- Division of Child and Adolescent Psychiatry, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- University of Maryland Child and Adolescent Mental Health Innovations Center, Baltimore, Maryland, United States of America
| | - Maureen Groer
- University of South Florida, Tampa, Florida, United States of America
| | - Robert Dantzer
- The University of Texas, MD Anderson Cancer Center, Houston, Texas, United States of America
| | - Dan Rujescu
- Section of Molecular and Clinical Neurobiology, Ludwig Maximilians University, Munich, Germany
- Department of Psychiatry, University of Halle-Wittenberg, Halle, Germany
| | - Teodor T. Postolache
- Mood and Anxiety Program, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- University of Maryland Child and Adolescent Mental Health Innovations Center, Baltimore, Maryland, United States of America
- VISN 5 Capitol Health Care Network Mental Illness Research Education and Clinical Center (MIRECC), Baltimore, Maryland, United States of America
- VISN 19 MIRECC, Denver, Colorado, United States of America
- * E-mail:
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Aldámiz-Echevarría L, Bueno MA, Couce ML, Lage S, Dalmau J, Vitoria I, Andrade F, Llarena M, Blasco J, Alcalde C, Gil D, García MC, González-Lamuño D, Ruiz M, Ruiz MA, González D, Sánchez-Valverde F. Tetrahydrobiopterin therapy vs phenylalanine-restricted diet: impact on growth in PKU. Mol Genet Metab 2013; 109:331-8. [PMID: 23810227 DOI: 10.1016/j.ymgme.2013.05.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Accepted: 05/24/2013] [Indexed: 11/22/2022]
Abstract
BACKGROUND Treatment of phenylketonuria based upon strict vegetarian diets, with very low phenylalanine intake and supplemented by phenylalanine-free formula, has proven to be effective in preventing the development of long-term neurological sequelae due to phenylalanine accumulation. On the other hand, such diets have occasionally been reported to hinder normal development, some individuals presenting with growth retardation. Tetrahydrobiopterin therapy has opened up new treatment options for a significant proportion of phenylketonuric patients, enabling them to eat normal diets and be freed from the need to take synthetic supplements. However, little is known about how this therapy affects their physical development. METHODS We conducted a retrospective longitudinal study examining anthropometric characteristics (height, weight, body mass index and growth speed Z-scores) in a cohort of phenylketonuric patients on tetrahydrobiopterin therapy (38 subjects) comparing their characteristics with those of a group of phenylketonuric patients on phenylalanine-restricted diets (76 subjects). Nutritional issues were also considered, to further explore the possibility of higher natural protein intake being associated with better physical development. Data were collected every six months over two different periods of time (two or five years). RESULTS No improvement was observed in the aforementioned anthropometric variables in the cohort on tetrahydrobiopterin therapy, from prior to starting treatment to when they had been taking the drug for two or five years. Rather, in almost all cases there was a fall in the mean Z-score for the variables during these periods, although the changes were not significant in any case. Further, we found no statistically differences between the two groups at any considered time point. Growth impairment was also noted in the phenylketonuric patients on low-phenylalanine diets. Individuals on tetrahydrobiopterin therapy increased their natural protein intake and, in some instances, this treatment enabled individuals to eat normal diets, with protein intake meeting RDAs. No association was found, however, between higher protein intake and growth. CONCLUSION Our study identified growth impairment in patients with phenylketonuria on tetrahydrobiopterin, despite higher intakes of natural proteins. In fact, individuals undergoing long-term tetrahydrobiopterin treatment seemed to achieve similar developmental outcomes to those attained by individuals on more restricted diets.
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Affiliation(s)
- Luis Aldámiz-Echevarría
- Division of Metabolism, Cruces University Hospital, Plaza de Cruces, s/n, 48903 Barakaldo, Spain.
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Couce ML, Bóveda MD, Fernández-Marmiesse A, Mirás A, Pérez B, Desviat LR, Fraga JM. Molecular epidemiology and BH4-responsiveness in patients with phenylalanine hydroxylase deficiency from Galicia region of Spain. Gene 2013; 521:100-4. [PMID: 23500595 DOI: 10.1016/j.gene.2013.03.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Revised: 02/28/2013] [Accepted: 03/01/2013] [Indexed: 11/16/2022]
Abstract
Knowledge of hyperphenylalaninemia (HPA) mutational spectrum in a population allows in many cases an accurate prediction of the phenotype and tetrahydrobiopterin (BH4) responsiveness, thus selecting an adequate treatment. In this work, we have performed the molecular characterization of 105 HPA patients from Galicia, in the northwest region of Spain, evaluating their phenotype and BH4 response. The mutational spectrum analysis showed 47 distinct mutations in 89 families, 37 of them (78.7%) corresponding to missense mutations. Six mutations account for 47.2% of all the investigated alleles, each one with a frequency ≥ 5% (IVS10-11G>A, p.R261Q, p.V388M, p.R176L, p.E280K, p.A300S). The most prevalent HPA mutations in Galicia are the common Mediterranean mutation IVS10-11G>A and p.R261Q, with frequencies of 13.8% and 10.5%, respectively. One novel mutation (p.K361Q; c.1081A>C) was also reported. Although a good genotype-phenotype correlation is observed, there is no exact correlation for some genotypes involving mutations p.R261Q, p.I65T or IVS10-11G>A. Forty seven patients were monitored for post-challenge BH4, establishing genotype-based predictions of BH4-responsiveness in all of them. All phenylketonuric patients with 2 nonresponsive mutations were unresponsive to BH4 and patients with mutations previously associated with BH4 responsiveness in the two alleles had a clear positive response to the test, with the exception of 5 patients with mutations p.R261Q, p.I65T and p.R68S. Our study supports a similar degree of heterogeneity of the HPA mutation spectrum in Galicia compared to reported data from Southern Europe. Patients carrying null mutations in both alleles showed the highest degree of concordance with the most severe phenotypes. Genotype is a good predictor of BH4 response.
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Affiliation(s)
- M L Couce
- Unit of Diagnosis and Treatment of Congenital Metabolic Diseases, Department of Pediatrics, Hospital Clinico Universitario de Santiago, Santiago de Compostela, Spain.
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