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Dar W. Aspartame-induced cognitive dysfunction: Unveiling role of microglia-mediated neuroinflammation and molecular remediation. Int Immunopharmacol 2024; 135:112295. [PMID: 38776852 DOI: 10.1016/j.intimp.2024.112295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 05/14/2024] [Accepted: 05/16/2024] [Indexed: 05/25/2024]
Abstract
Aspartame, an artificial sweetener, is consumed by millions of people globally. There are multiple reports of aspartame and its metabolites affecting cognitive functions in animal models and humans, which include learning problems, headaches, seizures, migraines, irritable moods, anxiety, depression, and insomnia. These cognitive deficits and associated symptoms are partly attributed to dysregulated excitatory and inhibitory neurotransmitter balance due to aspartate released from aspartame, resulting in an excitotoxic effect in neurons, leading to neuronal damage. However, microglia, a central immunocompetent cell type in brain tissue and a significant player in inflammation can contribute to the impact. Microglia rapidly respond to changes in CNS homeostasis. Aspartame consumption might affect the microglia phenotype directly via methanol-induced toxic effects and indirectly via aspartic acid-mediated excitotoxicity, exacerbating symptoms of cognitive decline. Long-term oral consumption of aspartame thus might change microglia's phenotype from ramified to activated, resulting in chronic or sustained activation, releasing excess pro-inflammatory molecules. This pro-inflammatory surge might lead to the degeneration of healthy neurons and other glial cells, impairing cognition. This review will deliberate on possible links and research gaps that need to be explored concerning aspartame consumption, ecotoxicity and microglia-mediated inflammatory cognitive impairment. The study covers a comprehensive analysis of the impact of aspartame consumption on cognitive function, considering both direct and indirect effects, including the involvement of microglia-mediated neuroinflammation. We also propose a novel intervention strategy involving tryptophan supplementation to mitigate cognitive decline symptoms in individuals with prolonged aspartame consumption, providing a potential solution to address the adverse effects of aspartame on cognitive function.
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Affiliation(s)
- Waseem Dar
- Translational Neurobiology and Disease Modelling Laboratory, Department of Life Sciences, School of Natural Sciences, Shiv Nadar Institution of Eminence, Greater Noida, 201314, India.
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Alavanda C, Ceylan Eİ, Kılavuz S, Çıkı K. Comprehensive analyses of phenylalanine hydroxylase variants and phenotypic characteristics of patients in the eastern region of Türkiye. J Pediatr Endocrinol Metab 2024; 0:jpem-2024-0091. [PMID: 38706300 DOI: 10.1515/jpem-2024-0091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2024] [Accepted: 04/17/2024] [Indexed: 05/07/2024]
Abstract
OBJECTIVES Phenylalanine hydroxylase (PAH) is predominantly a hepatic enzyme that catalyzes phenylalanine (Phe) into tyrosine, which is the rate-limiting step in Phe catabolism. Biallelic variants in the PAH gene cause PAH enzyme deficiency. Phenylketonuria (PKU) is an autosomal recessive disorder that causes neurologic, behavioral, and dermatological findings. PKU could be divided clinically into three types based on the blood Phe levels: classic phenylketonuria (cPKU), mild-moderate phenylketonuria (mPKU), and mild hyperphenylalaninemia (MHP). This study aimed to determine the phenotypic and genotypic characteristics of Turkish PKU patients in the eastern region of Türkiye. METHODS Demographic characteristics, serum Phe levels, treatments, and PAH variants of 163 patients with PKU and hyperphenylalaninemia (HPA) were retrospectively evaluated. Blood Phe levels of the patients were analyzed with the high-performance liquid chromatography method. For PAH gene analysis, next-generation sequencing was performed. RESULTS Of the 163 patients included in the study, 38 (23.3 %) had cPKU, 16 (9.8 %) had mPKU, and 109 (66.9 %) had MHP. Homozygous variants in the PAH gene were detected in 66 (40.5 %) of the patients, while compound heterozygous variants were detected in 97 (59.5 %) patients. Two novel and 35 recurrent variants in the PAH gene were detected. Of the two novel variants, one was missense (p.Phe351Leu) and the other was frameshift (p.Met276Cysfs*65). The most frequently detected variants were p.Thr380Met (18 %), p.Arg261Gln (16.8 %), and p.Ala300Ser (12.8 %). All patients with the homozygous c.1066-11G>A variant exhibited cPKU phenotype. The c.898G>T (p.Ala300Ser), c.1139C>T (p.Thr380Met), and c.1208C>T (p.Ala403Val) variants were statistically related to mild phenotype. On the other hand, c.592_613del (p.Tyr198Serfs*136), c.1028A>G (p.Tyr343Cys), and c.782G>A (p.Arg261Gln) variants were more frequently detected in the cPKU group. CONCLUSIONS Our study, conducted with patients from the eastern region of Türkiye, demonstrates the genetic heterogeneity in the Turkish population. Simultaneously, our research contributes to genotype-phenotype correlation and expands the genotypic spectrum by identifying novel variants.
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Affiliation(s)
- Ceren Alavanda
- Department of Medical Genetics, Van Research and Training Hospital, Van, Türkiye
| | - Emine İpek Ceylan
- Department of Medical Genetics, Van Research and Training Hospital, Van, Türkiye
- Department of Medical Genetics, Dr Abdurrahman Yurtaslan Ankara Oncology Education and Research Hospital, Ankara, Türkiye
| | - Sebile Kılavuz
- Division of Child Nutrition and Metabolism, Department of Pediatrics, School of Medicine, Marmara University, İstanbul, Türkiye
- Division of Child Nutrition and Metabolism, Department of Pediatrics, Van Research and Training Hospital, Van, Türkiye
| | - Kısmet Çıkı
- Division of Child Nutrition and Metabolism, Department of Pediatrics, Van Research and Training Hospital, Van, Türkiye
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Trefz F, Frauendienst-Egger G, Dienel G, Cannet C, Schmidt-Mader B, Haas D, Blau N, Himmelreich N, Spraul M, Freisinger P, Dobrowolski S, Berg D, Pilotto A. Does hyperphenylalaninemia induce brain glucose hypometabolism? Cerebral spinal fluid findings in treated adult phenylketonuric patients. Mol Genet Metab 2024; 142:108464. [PMID: 38537426 DOI: 10.1016/j.ymgme.2024.108464] [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: 01/31/2024] [Revised: 03/21/2024] [Accepted: 03/22/2024] [Indexed: 05/08/2024]
Abstract
Despite numerous studies in human patients and animal models for phenylketonuria (PKU; OMIM#261600), the pathophysiology of PKU and the underlying causes of brain dysfunction and cognitive problems in PKU patients are not well understood. In this study, lumbar cerebral spinal fluid (CSF) was obtained immediately after blood sampling from early-treated adult PKU patients who had fasted overnight. Metabolite and amino acid concentrations in the CSF of PKU patients were compared with those of non-PKU controls. The CSF concentrations and CSF/plasma ratios for glucose and lactate were found to be below normal, similar to what has been reported for glucose transporter1 (GLUT1) deficiency patients who exhibit many of the same clinical symptoms as untreated PKU patients. CSF glucose and lactate levels were negatively correlated with CSF phenylalanine (Phe), while CSF glutamine and glutamate levels were positively correlated with CSF Phe levels. Plasma glucose levels were negatively correlated with plasma Phe concentrations in PKU subjects, which partly explains the reduced CSF glucose concentrations. Although brain glucose concentrations are unlikely to be low enough to impair brain glucose utilization, it is possible that the metabolism of Phe in the brain to produce phenyllactate, which can be transported across the blood-brain barrier to the blood, may consume glucose and/or lactate to generate the carbon backbone for glutamate. This glutamate is then converted to glutamine and carries the Phe-derived ammonia from the brain to the blood. While this mechanism remains to be tested, it may explain the correlations of CSF glutamine, glucose, and lactate concentrations with CSF Phe.
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Affiliation(s)
- Friedrich Trefz
- Heidelberg University, Medical Faculty of Heidelberg, Center for Child and Adolescent Medicine, Division of Child Neurology and Metabolic Medicine, Heidelberg, Germany.
| | | | - Gerald Dienel
- Department of Neurology, University of Arkansas for Medical Sciences, Little Rock, AR, United States; Department of Cell Biology and Physiology, University of New Mexico, Albuquerque, NM, United States
| | | | - Brigitte Schmidt-Mader
- Heidelberg University, Medical Faculty of Heidelberg, Center for Child and Adolescent Medicine, Division of Child Neurology and Metabolic Medicine, Heidelberg, Germany
| | - Dorothea Haas
- Heidelberg University, Medical Faculty of Heidelberg, Center for Child and Adolescent Medicine, Division of Child Neurology and Metabolic Medicine, Heidelberg, Germany
| | - Nenad Blau
- University Children's Hospital Zürich, Zürich, Switzerland
| | | | | | - Peter Freisinger
- Klinikum Reutlingen, Department of Pediatrics, Reutlingen, Germany
| | - Steven Dobrowolski
- Department of Pathology, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15224, United States
| | - Daniela Berg
- Department of Neurology, University Hospital of Schleswig-Holstein, Kiel, Germany
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van Wegberg AMJ, van der Weerd JC, Engelke UFH, Coene KLM, Jahja R, Bakker SJL, Huijbregts SCJ, Wevers RA, Heiner-Fokkema MR, van Spronsen FJ. The clinical relevance of novel biomarkers as outcome parameter in adults with phenylketonuria. J Inherit Metab Dis 2024. [PMID: 38556470 DOI: 10.1002/jimd.12732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 03/07/2024] [Accepted: 03/12/2024] [Indexed: 04/02/2024]
Abstract
Recent studies in PKU patients identified alternative biomarkers in blood using untargeted metabolomics. To test the added clinical value of these novel biomarkers, targeted metabolomics of 11 PKU biomarkers (phenylalanine, glutamyl-phenylalanine, glutamyl-glutamyl-phenylalanine, N-lactoyl-phenylalanine, N-acetyl-phenylalanine, the dipeptides phenylalanyl-phenylalanine and phenylalanyl-leucine, phenylalanine-hexose conjugate, phenyllactate, phenylpyruvate, and phenylacetate) was performed in stored serum samples of the well-defined PKU patient-COBESO cohort and a healthy control group. Serum samples of 35 PKU adults and 20 healthy age- and sex-matched controls were analyzed using ultra-high performance liquid chromatography quadrupole time-of-flight mass spectrometry. Group differences were tested using the Mann-Whitney U test. Multiple linear regression analyses were performed with these biomarkers as predictors of (neuro-)cognitive functions working memory, sustained attention, inhibitory control, and mental health. Compared to healthy controls, phenylalanine, glutamyl-phenylalanine, N-lactoyl-phenylalanine, N-acetyl-phenylalanine, phenylalanine-hexose conjugate, phenyllactate, phenylpyruvate, and phenylacetate were significant elevated in PKU adults (p < 0.001). The remaining three were below limit of detection in PKU and controls. Both phenylalanine and N-lactoyl-phenylalanine were associated with DSM-VI Attention deficit/hyperactivity (R2 = 0.195, p = 0.039 and R2 = 0.335, p = 0.002, respectively) of the ASR questionnaire. In addition, N-lactoyl-phenylalanine showed significant associations with ASR DSM-VI avoidant personality (R2 = 0.265, p = 0.010), internalizing (R2 = 0.192, p = 0.046) and externalizing problems (R2 = 0.217, p = 0.029) of the ASR questionnaire and multiple aspects of the MS2D and FI tests, reflecting working memory with R2 between 0.178 (p = 0.048) and 0.204 (p = 0.033). Even though the strength of the models was not considered strong, N-lactoyl-phenylalanine outperformed phenylalanine in its association with working memory and mental health outcomes.
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Affiliation(s)
- A M J van Wegberg
- Division of Metabolic Diseases, University of Groningen, University Medical Center Groningen, Beatrix Children's Hospital, The Netherlands
| | - J C van der Weerd
- Department of Laboratory Medicine, Laboratory of Metabolic Diseases, University of Groningen, University Medical Centre Groningen, The Netherlands
| | - U F H Engelke
- Department of Human Genetics, Translational Metabolic Laboratory, Radboud University Medical Center, Nijmegen, The Netherlands
| | - K L M Coene
- Laboratory of Clinical Chemistry and Hematology, Máxima Medical Centre, Veldhoven, The Netherlands
| | - R Jahja
- Division of Metabolic Diseases, University of Groningen, University Medical Center Groningen, Beatrix Children's Hospital, The Netherlands
| | - S J L Bakker
- Department of Internal Medicine, University of Groningen, University Medical Center Groningen, The Netherlands
| | - S C J Huijbregts
- Department of Clinical Child and Adolescent Studies-Neurodevelopmental Disorders, Faculty of Social Sciences, Leiden University, Leiden, The Netherlands
| | - R A Wevers
- Department of Human Genetics, Translational Metabolic Laboratory, Radboud University Medical Center, Nijmegen, The Netherlands
| | - M R Heiner-Fokkema
- Department of Laboratory Medicine, Laboratory of Metabolic Diseases, University of Groningen, University Medical Centre Groningen, The Netherlands
| | - F J van Spronsen
- Division of Metabolic Diseases, University of Groningen, University Medical Center Groningen, Beatrix Children's Hospital, The Netherlands
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Piombarolo A, Ialongo C, Bizzarri M, Angeloni A. Systems Biology and Inborn Error of Metabolism: Analytical Strategy in Investigating Different Biochemical/Genetic Parameters. Methods Mol Biol 2024; 2745:191-210. [PMID: 38060187 DOI: 10.1007/978-1-0716-3577-3_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/08/2023]
Abstract
Inborn errors of metabolism (IEM) are a group of about 500 rare genetic diseases with large diversity and complexity due to number of metabolic pathways involved in. Establishing a correct diagnosis and identifying the specific clinical phenotype is consequently a difficult task. However, an inclusive diagnosis able in capturing the different clinical phenotypes is mandatory for successful treatment. However, in contrast with Garrod's basic assumption "one-gene one-disease," no "simple" correlation between genotype-phenotype can be vindicated in IEMs. An illustrative example of IEM is Phenylketonuria (PKU), an autosomal recessive inborn error of L-phenylalanine (Phe) metabolism, ascribed to variants of the phenylalanine hydroxylase (PAH) gene encoding for the enzyme complex phenylalanine-hydroxylase. Blood values of Phe allow classifying PKU into different clinical phenotypes, albeit the participation of other genetic/biochemical pathways in the pathogenetic mechanisms remains elusive. Indeed, it has been shown that the most serious complications, such as cognitive impairment, are not only related to the gene dysfunction but also to the patient's background and the participation of several nongenetic factors.Therefore, a Systems Biology-based strategy is required in addressing IEM complexity, and in identifying the interplay between different pathways in shaping the clinical phenotype. Such an approach should entail the concerted investigation of genomic, transcriptomics, proteomics, metabolomics profiles altogether with phenylalanine and amino acids metabolism. Noticeably, this "omic" perspective could be instrumental in planning personalized treatment, tailored accordingly to the disease profile and prognosis.
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Affiliation(s)
- Aurora Piombarolo
- Department of Experimental Medicine, Sapienza University, Rome, Italy
| | - Cristiano Ialongo
- Department of Experimental Medicine, Sapienza University, Rome, Italy
| | - Mariano Bizzarri
- Department of Experimental Medicine, Sapienza University, Rome, Italy
| | - Antonio Angeloni
- Department of Experimental Medicine, Sapienza University, Rome, Italy.
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Sun M, Li Y, Li P, Li G, Yan Y, Zou H. Analysis of gene variation and long-term follow-up in children with phenylalanine hydroxylase deficiency diagnosed by newborn screening. Zhejiang Da Xue Xue Bao Yi Xue Ban 2023; 52:701-706. [PMID: 38105703 PMCID: PMC10764183 DOI: 10.3724/zdxbyxb-2023-0450] [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: 09/18/2023] [Accepted: 11/15/2023] [Indexed: 12/19/2023]
Abstract
OBJECTIVES To retrospectively analyze the variation and characteristics of phenylalanine hydroxylase (PAH) gene, and to observe the long-term treatment effect and follow-up of newborns with PAH deficiency. METHODS Clinical data, treatment and follow-up results of 198 patients with PAH deficiency diagnosed by newborn screening in Jinan from 1996 to 2021 were collected. The genetic analysis of 55 patients with PAH deficiency diagnosed by newborn screening in Jinan and 213 patients referred from the surrounding areas of Jinan were summarized. Gene variations were checked by a customized Panel gene detection method. Blood phenylalanine-concentration and physical development indicators including height and weight were regularly monitored. Intellectual development was assessed using a neuropsychological development scale for patients aged 0-6 years and academic performance, and brain injury in patients was assessed using brain magnetic resonance imaging. RESULTS c.728G>A, c.158G>A, c.721C>T, c.1068C>A, c.611A>G variations were common in PAH gene. The genotype of c.158G>A variation is compound heterozygous variation, with mainly a mild hyperpheny-lalaninemia. 168 patients with PAH deficiency who were followed-up regularly had normal physical development without dwarfism or malnutrition. Among the 33 preschool patients who underwent mental development assessment, 2 were mentally retarded and the initial treatment age was older than 6 months. Nine patients with an average age of (17.13±2.42) years completed brain magnetic resonance imaging, one case was normal, and 8 cases were abnormal. There were patchy or patchy hyperintense foci near the bilateral lateral ventricles on T2WI, and the intellectual development was normal. Compared with the other eight patients, the blood phenylalanine concentration of the normal child was better and stably controlled within the ideal range. CONCLUSIONS c.728G>A, c.158G>A, c.721C>T, c.1068C>A, c.611A>G variations were common in PAH gene. After standardized treatment, most patients with PAH deficiency diagnosed by screening can obtain normal growth and intellectual development in adolescence, but there are different degrees of organic lesions in the cerebral white matter.
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Affiliation(s)
- Meng Sun
- Newborn Disease Screening Center, Jinan Maternal and Child Care Hospital, Jinan 250001, China.
| | - Yulin Li
- Newborn Disease Screening Center, Jinan Maternal and Child Care Hospital, Jinan 250001, China
| | - Panpan Li
- Newborn Disease Screening Center, Jinan Maternal and Child Care Hospital, Jinan 250001, China
| | - Gaijie Li
- Newborn Disease Screening Center, Jinan Maternal and Child Care Hospital, Jinan 250001, China
| | - Yan Yan
- Newborn Disease Screening Center, Jinan Maternal and Child Care Hospital, Jinan 250001, China
| | - Hui Zou
- Newborn Disease Screening Center, Jinan Maternal and Child Care Hospital, Jinan 250001, China.
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Douillard C, Arnoux JB, Bouée S, Jacob C, Schneider KM, Theil J, Charrière S, Maillot F. Health status and comorbidities of adult patients with late-diagnosed phenylketonuria (PKU) born before the newborn screening in France - A nationwide study of health insurance claims data. Mol Genet Metab 2023; 140:107704. [PMID: 37812967 DOI: 10.1016/j.ymgme.2023.107704] [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: 07/16/2023] [Revised: 09/25/2023] [Accepted: 09/28/2023] [Indexed: 10/11/2023]
Abstract
BACKGROUND Phenylketonuria (PKU) is an inborn error of metabolism. When diagnosed late, it causes developmental delay or severe irreversible intellectual disability. This study aimed at evaluating the health status and healthcare consumption of late-diagnosed PKU patients in France. METHODS This retrospective observational study used health insurance claims data from the French SNDS (Système National des Données de Santé) database, which contains data from over 66 million French inhabitants. Patients with PKU were identified between 2006 and 2018 by ICD-10 diagnosis codes E70.0 / E70.1 documented as a chronic condition (affection de longue durée - ALD) or in the inpatient setting. Patients with PKU were matched to controls by age, sex, and region. Patients with late-diagnosed PKU were defined as patients born before the nationwide implementation of newborn screening in France in 1972. Outcomes were analyzed for the year 2018. RESULTS In total, 3549 patients with PKU were identified in the database on January 1st, 2018. Of those, 3469 patients could be matched to 17,170 controls without PKU. Of these, 2175 patients were at least 16 years old of whom 647 patients were categorized as late-diagnosed. The late-diagnosed PKU patients suffered significantly more often from hypertension (60.9% vs. 50.4%, p < 0.0001), hypercholesterolemia (41.7% vs. 26.9%, p < 0.0001), diabetes (24.4% vs. 14.1%, p < 0.0001), depression (20.6% vs. 13.8%, p < 0.0001), ischemic heart disease (16.1% vs. 6.6%, p < 0.0001), obesity (7.9% vs. 2.5%, inpatient diagnoses only, p < 0.0001), and chronic kidney disease (5.2% vs. 1.3%, inpatient diagnoses only, p < 0.0001) compared with their non-PKU controls. Consequently, significantly more patients with late-diagnosed PKU received medication to treat comorbidities associated with the nervous (82.6% vs 77.0%; p = 0.0021) and cardiovascular system (69.5% vs 58.0%; p < 0.0001). Overall, only 3.4% of patients with late-diagnosed PKU received dietary amino-acid supplements and 0.7% received sapropterin. CONCLUSION The results indicate that PKU is associated with a significantly higher risk of comorbidities along with increased pharmaceutical prescriptions in patients with late-diagnosed PKU, compared with non-PKU controls. The increased risk of comorbidities was more pronounced than in patients with early-diagnosed PKU, as shown in previous research, but these patients are older than those with early-diagnosed PKU. Only few late-diagnosed patients were treated specifically for PKU. Patients with late-diagnosed PKU should be referred to specialized centers to prevent and manage comordities and introduce PKU-specific treatment when it is possible.
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Affiliation(s)
- Claire Douillard
- Service d'Endocrinologie, Diabétologie et Métabolisme et Centre de Référence des Maladies Héréditaires du Métabolisme, Hôpital Huriez, CHU de Lille, 59037 Lille, France.
| | - Jean-Baptiste Arnoux
- Centre de Référence des Maladies Héréditaires du Métabolisme, Hôpital Necker-Enfants Malades, APHP, 149 rue de Sèvres, 75015 Paris, France.
| | - Stéphane Bouée
- CEMKA, 43 boulevard du Maréchal Joffre, 92340 Bourg-La-Reine, France.
| | | | | | - Julia Theil
- Xcenda GmbH, Lange Laube 31, 30159 Hannover, Germany.
| | - Sybil Charrière
- Hospices Civils de Lyon, Department of endocrinology, diabetologia, metabolic diseases and nutrition, Hôpital Louis Pradel, 69600 Bron, France; CarMen laboratory, INSERM, INRAE, Université Claude Bernard Lyon 1, 69310, Pierre Bénite, France.
| | - Francois Maillot
- Service de médecine interne, CHRU et Université de Tours, Tours, France.
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Manti F, Nardecchia F, De Leo S, Carducci C, Romani C, Palermo L, Angeloni A, Leuzzi V. Towards precision medicine for phenylketonuria: The effect of restoring a strict metabolic control in adult patients with early-treated phenylketonuria. Mol Genet Metab 2023; 140:107666. [PMID: 37549444 DOI: 10.1016/j.ymgme.2023.107666] [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: 06/11/2023] [Revised: 07/23/2023] [Accepted: 07/24/2023] [Indexed: 08/09/2023]
Abstract
BACKGROUND AND OBJECTIVE Neonatal screening and early treatment have changed the natural history of PKU, preventing severe neurological and intellectual disability. Nevertheless, the outcome of the disease in early-treated adult patients (ETPKU) is less than optimal, the predictive value of metabolic biomarkers is feeble, and the recommended levels of blood phenylalanine (Phe) for adulthood are controversial. A crucial question whose answer will improve our understanding and treatment of PKU is whether cognitive outcomes can be modulated by levels of Phe even in early-treated adults. To address this question, we carried out an interventional study in seven ETPKU women planning a pregnancy. METHODS They underwent an extensive neurocognitive assessment at baseline, and 3 and 6 months after having attained the blood Phe concentration recommended to prevent PKU fetopathy, but before pregnancy. RESULTS After 3 and 6 months with a stable blood Phe level of about 240 μmol/L, all participants experienced significant improvements in almost all neurocognitive domains and tasks. IQ also increased of 11 to 21 points from the last assessment before enrolment. This pattern remained strong and consistent after correction for multiple comparisons. CONCLUSION Our results indicate that a) strong cognitive improvement is possible even in adulthood and may be demonstrated by lowering Phe near normal levels; b) testing cognition under different metabolic conditions may unveil an individual vulnerability to Phe. These results pave the way for personalised treatment of the disease in adults with ETPKU.
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Affiliation(s)
- Filippo Manti
- Department of Human Neuroscience - Unit of Child Neurology and Psychiatry, Sapienza University of Rome, Rome, Italy
| | - Francesca Nardecchia
- Department of Human Neuroscience - Unit of Child Neurology and Psychiatry, Sapienza University of Rome, Rome, Italy
| | - Sabrina De Leo
- Department of Clinical Medicine, Azienda Ospedaliero Universitaria Policlinico Umberto I, Rome, Italy
| | - Claudia Carducci
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
| | - Cristina Romani
- School of Life and Health Sciences, Aston University, Birmingham, UK
| | - Liana Palermo
- Department of Medical and Surgical Sciences, Magna Graecia University of Catanzaro, Catanzaro, Italy
| | - Antonio Angeloni
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
| | - Vincenzo Leuzzi
- Department of Human Neuroscience - Unit of Child Neurology and Psychiatry, Sapienza University of Rome, Rome, Italy.
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de Almeida Duarte CM, Piazzon FB, Rocco IS, de Mello CB. Influence of blood phenylalanine level variations on the development of executive functions and social cognition in children with phenylketonuria. J Pediatr (Rio J) 2023; 99:507-513. [PMID: 37178714 PMCID: PMC10492152 DOI: 10.1016/j.jped.2023.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 04/03/2023] [Accepted: 04/04/2023] [Indexed: 05/15/2023] Open
Abstract
OBJECTIVE To investigate the performance of 27 children with phenylketonuria (PKU) in tests of Executive Functions (EF) and Social Cognition (SC), and their associations with metabolic control inferred by phenylalanine (Phe) levels. METHODS The PKU group was dichotomized according to baseline Phe-levels into; "classical PKU"(n = 14), with Phe-levels above 1200 μmol/L (> 20 mg/dL); and "mild PKU" (n = 13) with Phe-between 360 and 1200 μmol/L (6-20 mg/dL). The neuropsychological assessment focused on the EF and SC subtests of the NEPSY-II battery and intellectual performance. Children were compared to age-matched healthy participants. RESULTS Participants with PKU presented significantly lower Intellectual Quotient (IQ) compared to controls (p = 0.001). Regarding EF analysis adjusted by age and IQ, significant differences between groups were observed only in the executive attention subtests (p = 0.029). The SC set of variables was significantly different between groups (p = 0.003), as in the affective recognition task (p < 0.001). In the PKU group, the relative variation of Phe-achieved 32.1 ± 21.0%. Relative Phe-variation was correlated only with measures of Working Memory (p < 0.001), Verbal Fluency (p = 0.004), Inhibitory Control (p = 0.035) and Theory of Mind (p = 0.003). CONCLUSIONS Phonological Verbal Fluency, Working Memory, Inhibitory Control, and Theory of Mind were shown to be most vulnerable when there is non-ideal metabolic control. Variations in the level of Phe-may have a selective negative effect on Executive Functions and Social Cognition, but not on intellectual performance.
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Affiliation(s)
| | - Flavia Balbo Piazzon
- University Hospital Liège & University of Liège, Department of Pediatrics, Neuromuscular Reference Center, Liège, Belgium; Universidade de São Paulo (USP), Unidade Neurometabólica, São Paulo, SP, Brazil
| | - Isadora Salvador Rocco
- Universidade Federal de São Paulo (UNIFESP), Programa de Pós-Graduação em Cardiologia e Departamento de Cirurgia Cardíaca, São Paulo, SP, Brazil.
| | - Claudia Berlim de Mello
- Universidade Federal de São Paulo (UNIFESP), Departamento de Psicobiologia, São Paulo, SP, Brazil
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Wang MW, Wu CJ, Zhang ZQ. Neurological and imaging phenotypes of adults with untreated phenylketonuria: new cases and literature review. J Neurol 2023:10.1007/s00415-023-11760-9. [PMID: 37162580 DOI: 10.1007/s00415-023-11760-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 05/02/2023] [Accepted: 05/04/2023] [Indexed: 05/11/2023]
Abstract
OBJECTIVES Phenylketonuria (PKU) is the most prevalent congenital disease of amino acid metabolism. Neurological manifestations usually complicate PKU in untreated adult patients. This study describes neurological and imaging phenotypes of adult patients with untreated PKU. METHODS We investigated a cohort of 320 unrelated adult patients with suspected genetic leukoencephalopathies using whole-exome sequencing (WES). We analyzed the phenotypic features of adult PKU patients in our cohort and summarized cases reported in the literature. RESULTS We identified 10 patients in our cohort and 12 patients in the literature, who presented with neurological manifestations and were diagnosed with PKU in adulthood. Approximately 60% of these patients had onset of clinical features in adulthood. The most common neurological symptoms of patients presenting in adulthood were cognitive disturbance and spastic paralysis, followed by vision loss, cerebellar ataxia, weakness of limbs, and seizure. This differed from that of patients presenting with PKU features in childhood, who consistently had mental retardation with various neurological complications emerging during a broad age range. Imaging findings were similar between patients presenting with clinical features in childhood compared with adulthood, comprising symmetric periventricular white matter hyperintense on T2-weighted imaging and diffusion-weighted imaging predominantly in the parietal and occipital lobes. Also, normal brain imaging and diffuse leukoencephalopathies were observed in both patient groups. CONCLUSION PKU with clinical features presenting in adulthood is an atypical subtype and should be considered during diagnosis of adults with neurological symptoms and leukoencephalopathy. DWI seems to be most helpful to distinguish patients with PKU. Additionally, we demonstrate that PKU constitutes a part (3.1%) of adult genetic leukoencephalopathies.
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Affiliation(s)
- Meng-Wen Wang
- Department of Neurology and Institute of Neurology, The First Affiliated Hospital of Fujian Medical University, Fuzhou, 350005, China
| | - Chu-Jun Wu
- Department of Neurology, Beijing Tiantan Hospital, National Clinical Research Center for Neurological Diseases, Capital Medical University, No.119 South 4Th Ring West Road, Fengtai District, Beijing, 100070, China
- China National Clinical Research Center for Neurological Diseases, Beijing, 100070, China
| | - Zai-Qiang Zhang
- Department of Neurology, Beijing Tiantan Hospital, National Clinical Research Center for Neurological Diseases, Capital Medical University, No.119 South 4Th Ring West Road, Fengtai District, Beijing, 100070, China.
- China National Clinical Research Center for Neurological Diseases, Beijing, 100070, China.
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11
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Moritz L, Klotz K, Grünert SC, Hannibal L, Spiekerkoetter U. Metabolic phenotyping in phenylketonuria reveals disease clustering independently of metabolic control. Mol Genet Metab 2023; 138:107509. [PMID: 36791482 DOI: 10.1016/j.ymgme.2023.107509] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 01/11/2023] [Accepted: 01/12/2023] [Indexed: 01/17/2023]
Abstract
Phenylketonuria (PKU, MIM #261600) is one of the most common inborn errors of metabolism (IEM) with an incidence of 1:10000 in the European population. PKU is caused by autosomal recessive mutations in phenylalanine hydroxylase (PAH) and manifests with elevation of phenylalanine (Phe) in plasma and urine. Untreated PKU manifests with intellectual disability including seizures, microcephaly and behavioral abnormalities. Early treatment and good compliance result in a normal intellectual outcome in many but not in all patients. This study examined plasma metabolites in patients with PKU (n = 27), hyperphenylalaninemia (HPA, n = 1) and healthy controls (n = 32) by LC- MS/MS. We hypothesized that PKU patients would exhibit a distinct "submetabolome" compared to that of healthy controls. We further hypothesized that the submetabolome of PKU patients with good metabolic control would resemble that of healthy controls. Results from this study show: (i) Distinct clustering of healthy controls and PKU patients based on polar metabolite profiling, (ii) Increased and decreased concentrations of metabolites within and afar from the Phe pathway in treated patients, and (iii) A specific PKU-submetabolome independently of metabolic control assessed by Phe in plasma. We examined the relationship between PKU metabolic control and extended metabolite profiles in plasma. The PKU submetabolome characterized in this study represents the combined effects of dietary adherence, adjustments in metabolic pathways to compensate for defective Phe processing, as well as metabolic derangements that could not be corrected with dietary management even in patients classified as having good metabolic control. New therapeutic targets may be uncovered to approximate the PKU submetabolome to that of healthy controls and prevent long-term organ damage.
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Affiliation(s)
- Lennart Moritz
- Laboratory of Clinical Biochemistry and Metabolism, Department of General Pediatrics, Adolescent Medicine and Neonatology, Faculty of Medicine, Medical Center, University of Freiburg, 79106 Freiburg, Germany; Department of General Pediatrics, Adolescent Medicine and Neonatology, Faculty of Medicine, Medical Center, University of Freiburg, 79106 Freiburg, Germany
| | - Katharina Klotz
- Laboratory of Clinical Biochemistry and Metabolism, Department of General Pediatrics, Adolescent Medicine and Neonatology, Faculty of Medicine, Medical Center, University of Freiburg, 79106 Freiburg, Germany
| | - Sarah Catharina Grünert
- Department of General Pediatrics, Adolescent Medicine and Neonatology, Faculty of Medicine, Medical Center, University of Freiburg, 79106 Freiburg, Germany
| | - Luciana Hannibal
- Laboratory of Clinical Biochemistry and Metabolism, Department of General Pediatrics, Adolescent Medicine and Neonatology, Faculty of Medicine, Medical Center, University of Freiburg, 79106 Freiburg, Germany.
| | - Ute Spiekerkoetter
- Department of General Pediatrics, Adolescent Medicine and Neonatology, Faculty of Medicine, Medical Center, University of Freiburg, 79106 Freiburg, Germany.
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12
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Cognitive Functioning in Adults with Phenylketonuria in a Cohort of Spanish Patients. Behav Neurol 2023; 2023:9681740. [PMID: 36815863 PMCID: PMC9931468 DOI: 10.1155/2023/9681740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 12/14/2022] [Accepted: 12/15/2022] [Indexed: 02/10/2023] Open
Abstract
The early introduction of a low phenylalanine (Phe) diet has been demonstrated to be the most successful treatment in subjects with phenylketonuria (PKU), especially for preventing severe cognitive and neurological damages. However, it still concerns that even if treated in the first months of life with supplements and following a diet, they can show slight scores below people without PKU in neuropsychological assignments. We investigated 20 adults with classical PKU aged 19-48 years (mean age 29 years) and 20 heathy controls matched by age, gender, and years of education. Patients and controls were assessed with an extended neuropsychological battery, as well as psychological aspects and quality of life, also the last Phe level result was obtained. Results showed that the most affected cognitive domains are processing speed, executive functioning, memory, and also theory of mind, but very well-preserved verbal fluency, language, and visuospatial functioning. In quality of life, some significant results were seen specially in anxiety of Phe levels, anxiety of Phe levels during pregnancy, guilt if poor adherence to supplements, and if dietary protein restriction not followed. No significant results were obtained for the psychological variables. In conclusion, it has been shown that a combination of a low Phe diet, supplement intake, and keeping Phe levels in a low range seems appropriate to have the most normal and alike cognitive performance to persons without PKU.
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13
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Chen A, Pan Y, Chen J. Clinical, genetic, and experimental research of hyperphenylalaninemia. Front Genet 2023; 13:1051153. [PMID: 36685931 PMCID: PMC9845280 DOI: 10.3389/fgene.2022.1051153] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 12/06/2022] [Indexed: 01/06/2023] Open
Abstract
Hyperphenylalaninemia (HPA) is the most common amino acid metabolism defect in humans. It is an autosomal-recessive disorder of the phenylalanine (Phe) metabolism, in which high Phe concentrations and low tyrosine (Tyr) concentrations in the blood cause phenylketonuria (PKU), brain dysfunction, light pigmentation and musty odor. Newborn screening data of HPA have revealed that the prevalence varies worldwide, with an average of 1:10,000. Most cases of HPA result from phenylalanine hydroxylase (PAH) deficiency, while a small number of HPA are caused by defects in the tetrahydrobiopterin (BH4) metabolism and DnaJ heat shock protein family (Hsp40) member C12 (DNAJC12) deficiency. Currently, the molecular pathophysiology of the neuropathology associated with HPA remains incompletely understood. Dietary restriction of Phe has been highly successful, although outcomes are still suboptimal and patients find it difficult to adhere to the treatment. Pharmacological treatments, such as BH4 and phenylalanine ammonia lyase, are available. Gene therapy for HPA is still in development.
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Affiliation(s)
- Anqi Chen
- Department of Forensic Medicine, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Yukun Pan
- Barbell Therapeutics Co. Ltd., Shanghai, China,*Correspondence: Yukun Pan, ; Jinzhong Chen,
| | - Jinzhong Chen
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai, China,*Correspondence: Yukun Pan, ; Jinzhong Chen,
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14
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Thomas L, Olson A, Romani C. The impact of metabolic control on cognition, neurophysiology, and well-being in PKU: A systematic review and meta-analysis of the within-participant literature. Mol Genet Metab 2023; 138:106969. [PMID: 36599257 DOI: 10.1016/j.ymgme.2022.106969] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 12/09/2022] [Accepted: 12/10/2022] [Indexed: 12/15/2022]
Abstract
Phenylketonuria (PKU) is a metabolic disease where Phenylalanine (Phe) rises much above normal levels. Cross-sectional and correlational studies provide valuable information on the importance of maintaining low blood-Phe to achieve good outcomes, but they may be confounded, at least partially, by differences in participant demographics. Moreover, the effect of Phe at older ages is difficult to ascertain because of strong associations between Phe levels across ages. Within-participant studies avoid confounding issues. We have reviewed these studies. We followed PRISMA guidelines to search the literature for studies reporting the impact of Phe changes within participants. Phe was either increased or decreased through diet relaxation/resumption or through pharmacological interventions. Forty-six separate articles reported, singly or in combination, results on cognition (N = 37), well-being (N = 22) and neurophysiological health (N = 14). For all studies, we established, in a binary way, whether a benefit of lower Phe was or was not demonstrated and compared numbers showing benefit versus a null or negative outcome. We then analyzed whether critical parameters (e.g., length of the study/condition for the change, size of Phe change achieved) influenced presence or absence of benefit. For a subset of studies that reported quantitative cognitive outcomes, we carried out a meta-analysis to estimate the size of change in cognitive performance associated with a change in Phe and its significance. There were significantly more studies with benefits than no benefits, both for cognitive and well-being outcomes, and a trend in this direction for neurophysiological outcomes. The meta-analysis showed a highly significant effect size both overall (0.55) and when studies with adults/adolescents were considered separately (0.57). There was some indication that benefits were easier to demonstrate when differences in Phe were larger and achieved across a longer period, but these effects were not always consistent. These results reinforce results from the literature by demonstrating the importance of lower Phe in children as well as in adolescents and adults, even when confounding factors in group composition are eliminated. The field would benefit from further studies where Phe levels are contrasted within-participants to ascertain how much Phe needs to be changed and for how long to see a difference and which measures demonstrate a difference (e.g., which cognitive tasks).
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15
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Rezaie M, Nemati F, Firoozbakhtian A, Tabesh H, Ganjali MR, Hosseini M. Three‐Dimensional Graphene Network Decorated with Bimetallic Cerium/Copper Oxide Nanoparticles for Non‐Enzymatic Diagnosis of Phenylketonuria. ChemistrySelect 2022. [DOI: 10.1002/slct.202203123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Maryam Rezaie
- Nanobiosensors Lab Department of Life Science Engineering Faculty of New Sciences & Technologies University of Tehran Tehran 1439817435 Iran
| | - Fatemeh Nemati
- Nanobiosensors Lab Department of Life Science Engineering Faculty of New Sciences & Technologies University of Tehran Tehran 1439817435 Iran
| | - Ali Firoozbakhtian
- Nanobiosensors Lab Department of Life Science Engineering Faculty of New Sciences & Technologies University of Tehran Tehran 1439817435 Iran
| | - Hadi Tabesh
- Department of Life Science Engineering Faculty of New Sciences & Technologies University of Tehran Tehran Iran
| | - Mohammad Reza Ganjali
- Center of Excellence in Electrochemistry School of Chemistry College of Science University of Tehran Tehran 1439817435 Iran
| | - Morteza Hosseini
- Nanobiosensors Lab Department of Life Science Engineering Faculty of New Sciences & Technologies University of Tehran Tehran 1439817435 Iran
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16
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Romani C, Olson A, Aitkenhead L, Baker L, Patel D, Spronsen FV, MacDonald A, Wegberg AV, Huijbregts S. Meta-analyses of cognitive functions in early-treated adults with phenylketonuria. Neurosci Biobehav Rev 2022; 143:104925. [PMID: 36283539 DOI: 10.1016/j.neubiorev.2022.104925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Revised: 10/07/2022] [Accepted: 10/21/2022] [Indexed: 11/05/2022]
Abstract
Our study estimated size of impairment for different cognitive functions in early-treated adults with PKU (AwPKU) by combining literature results in a meta-analytic way. We analysed a large set of functions (N = 19), each probed by different measures (average = 12). Data were extracted from 26 PKU groups and matched controls, with 757 AwPKU contributing 220 measures. Effect sizes (ESs) were computed using Glass' ∆ where differences in performance between clinical/PKU and control groups are standardized using the mean and standard deviation of the control groups. Significance was assessed using measures nested within independent PKU groups as a random factor. The weighted Glass' ∆ was - 0.44 for all functions taken together, and - 0.60 for IQ, both highly significant. Separate, significant impairments were found for most functions, but with great variability (ESs from -1.02 to -0.18). The most severe impairments were in reasoning, visual-spatial attention speed, sustained attention, visuo-motor control, and flexibility. Effect sizes were larger with speed than accuracy measures, and with visuo-spatial than verbal stimuli. Results show a specific PKU profile that needs consideration when monitoring the disease.
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Affiliation(s)
| | - Andrew Olson
- Psychology Department, University of Birmingham, UK.
| | | | - Lucy Baker
- Psychology Department, Aston University, UK.
| | | | | | - Anita MacDonald
- Birmingham Women' s and Children's NHS Foundation Trust, UK.
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17
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Rezaie M, Nemati F, Firoozbakhtian A, Tabesh H, Hosseini M. Three-dimensional Graphene Network Decorated with Bimetallic Cerium/Copper Oxide Nanoparticles for Non-enzymatic Diagnosis of Phenylketonuria. Microchem J 2022. [DOI: 10.1016/j.microc.2022.108188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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18
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Elhawary NA, AlJahdali IA, Abumansour IS, Elhawary EN, Gaboon N, Dandini M, Madkhali A, Alosaimi W, Alzahrani A, Aljohani F, Melibary EM, Kensara OA. Genetic etiology and clinical challenges of phenylketonuria. Hum Genomics 2022; 16:22. [PMID: 35854334 PMCID: PMC9295449 DOI: 10.1186/s40246-022-00398-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 07/08/2022] [Indexed: 02/08/2023] Open
Abstract
This review discusses the epidemiology, pathophysiology, genetic etiology, and management of phenylketonuria (PKU). PKU, an autosomal recessive disease, is an inborn error of phenylalanine (Phe) metabolism caused by pathogenic variants in the phenylalanine hydroxylase (PAH) gene. The prevalence of PKU varies widely among ethnicities and geographic regions, affecting approximately 1 in 24,000 individuals worldwide. Deficiency in the PAH enzyme or, in rare cases, the cofactor tetrahydrobiopterin results in high blood Phe concentrations, causing brain dysfunction. Untreated PKU, also known as PAH deficiency, results in severe and irreversible intellectual disability, epilepsy, behavioral disorders, and clinical features such as acquired microcephaly, seizures, psychological signs, and generalized hypopigmentation of skin (including hair and eyes). Severe phenotypes are classic PKU, and less severe forms of PAH deficiency are moderate PKU, mild PKU, mild hyperphenylalaninaemia (HPA), or benign HPA. Early diagnosis and intervention must start shortly after birth to prevent major cognitive and neurological effects. Dietary treatment, including natural protein restriction and Phe-free supplements, must be used to maintain blood Phe concentrations of 120-360 μmol/L throughout the life span. Additional treatments include the casein glycomacropeptide (GMP), which contains very limited aromatic amino acids and may improve immunological function, and large neutral amino acid (LNAA) supplementation to prevent plasma Phe transport into the brain. The synthetic BH4 analog, sapropterin hydrochloride (i.e., Kuvan®, BioMarin), is another potential treatment that activates residual PAH, thus decreasing Phe concentrations in the blood of PKU patients. Moreover, daily subcutaneous injection of pegylated Phe ammonia-lyase (i.e., pegvaliase; PALYNZIQ®, BioMarin) has promised gene therapy in recent clinical trials, and mRNA approaches are also being studied.
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Affiliation(s)
- Nasser A. Elhawary
- grid.412832.e0000 0000 9137 6644Department of Medical Genetics, College of Medicine, Umm Al-Qura University, P.O. Box 57543, Mecca, 21955 Saudi Arabia
| | - Imad A. AlJahdali
- grid.412832.e0000 0000 9137 6644Department of Community Medicine, College of Medicine, Umm Al-Qura University, P.O. Box 57543, Mecca, 21955 Saudi Arabia
| | - Iman S. Abumansour
- grid.412832.e0000 0000 9137 6644Department of Medical Genetics, College of Medicine, Umm Al-Qura University, P.O. Box 57543, Mecca, 21955 Saudi Arabia
| | - Ezzeldin N. Elhawary
- grid.123047.30000000103590315Faculty of Medicine, MS Genomic Medicine Program, University of Southampton, Southampton General Hospital, Southampton, UK
| | - Nagwa Gaboon
- grid.7269.a0000 0004 0621 1570Department of Clinical Genetics, Faculty of Medicine, Ain Shams University, Cairo, Egypt
| | - Mohammed Dandini
- Department of Laboratory and Blood Bank, Maternity and Children Hospital, Mecca, Saudi Arabia
| | - Abdulelah Madkhali
- grid.415254.30000 0004 1790 7311Department of Pathology and Laboratory Medicine, King Abdulaziz Medical City, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia
| | - Wafaa Alosaimi
- Department of Hematology, Maternity and Children Hospital, Mecca, Saudi Arabia
| | - Abdulmajeed Alzahrani
- Department of Laboratory and Blood Bank at Maternity and Children Hospital, Mecca, Saudi Arabia
| | - Fawzia Aljohani
- Department of Pediatric Clinics, Maternity and Children Hospital, King Salman Medical City, Madinah, Saudi Arabia
| | - Ehab M. Melibary
- grid.412832.e0000 0000 9137 6644Department of Medical Genetics, College of Medicine, Umm Al-Qura University, P.O. Box 57543, Mecca, 21955 Saudi Arabia
| | - Osama A. Kensara
- grid.412832.e0000 0000 9137 6644Department of Clinical Nutrition, Faculty of Applied Medical Sciences, Umm Al-Qura University, Jeddah, Saudi Arabia
- Department of Biochemistry, Batterjee Medical College, Jeddah, Saudi Arabia
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Dobrowolski SF, Phua YL, Vockley J, Goetzman E, Blair HC. Phenylketonuria oxidative stress and energy dysregulation: Emerging pathophysiological elements provide interventional opportunity. Mol Genet Metab 2022; 136:111-117. [PMID: 35379539 PMCID: PMC9832337 DOI: 10.1016/j.ymgme.2022.03.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 03/24/2022] [Accepted: 03/25/2022] [Indexed: 01/13/2023]
Abstract
Phenylalanine hydroxylase (PAH) deficient phenylketonuria (PKU) is rightfully considered the paradigm treatable metabolic disease. Dietary substrate restriction (i.e. phenylalanine (Phe) restriction) was applied >60 years ago and remains the primary PKU management means. The traditional model of PKU neuropathophysiology dictates blood Phe over-representation directs asymmetric blood:brain barrier amino acid transport through the LAT1 transporter with subsequent increased cerebral Phe concentration and low concentrations of tyrosine (Tyr), tryptophan (Trp), leucine (Leu), valine (Val), and isoleucine (Ile). Low Tyr and Trp concentrations generate secondary serotonergic and dopaminergic neurotransmitter paucities, widely attributed as drivers of PKU neurologic phenotypes. White matter disease, a central PKU characteristic, is ascribed to Phe-mediated tissue toxicity. Impaired cerebral protein synthesis, by reduced concentrations of non-Phe large neutral amino acids, is another cited pathological mechanism. The PKU amino acid transport model suggests Phe management should be more efficacious than is realized, as even early identified, continuously treated patients that retain therapy compliance into adulthood, demonstrate neurologic disease elements. Reduced cerebral metabolism was an early-recognized element of PKU pathology. Legacy data (late 1960's to mid-1970's) determined the Phe catabolite phenylpyruvate inhibits mitochondrial pyruvate transport. Respirometry of Pahenu2 cerebral mitochondria have attenuated respiratory chain complex 1 induction in response to pyruvate substrate, indicating reduced energy metabolism. Oxidative stress is intrinsic to PKU and Pahenu2 brain tissue presents increased reactive oxygen species. Phenylpyruvate inhibits glucose-6-phosphate dehydrogenase that generates reduced niacinamide adenine dinucleotide phosphate the obligatory cofactor of glutathione reductase. Pahenu2 brain tissue metabolomics identified increased oxidized glutathione and glutathione disulfide. Over-represented glutathione disulfide argues for reduced glutathione reductase activity secondary to reduced NADPH. Herein, we review evidence of energy and oxidative stress involvement in PKU pathology. Data suggests energy deficit and oxidative stress are features of PKU pathophysiology, providing intervention-amenable therapeutic targets to ameliorate disease elements refractory to standard of care.
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Affiliation(s)
- Steven F Dobrowolski
- Department of Pathology, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15224, United States of America.
| | - Yu Leng Phua
- Division of Medical Genetics, Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, United States of America
| | - Jerry Vockley
- Division of Medical Genetics, Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, United States of America
| | - Eric Goetzman
- Division of Medical Genetics, Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, United States of America
| | - Harry C Blair
- Department of Pathology, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15224, United States of America; Veteran's Affairs Medical Center, Pittsburgh, PA, United States of America
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20
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Abgottspon S, Muri R, Christ SE, Hochuli M, Radojewski P, Trepp R, Everts R. Neural correlates of working memory and its association with metabolic parameters in early-treated adults with phenylketonuria. Neuroimage Clin 2022; 34:102974. [PMID: 35248901 PMCID: PMC8897706 DOI: 10.1016/j.nicl.2022.102974] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 02/22/2022] [Accepted: 02/25/2022] [Indexed: 11/18/2022]
Abstract
Working memory (WM) accuracy was significantly reduced in the PKU group. Reaction time did not differ between individuals with PKU and controls. No group differences were found with regard to neural activation. Neural activation was related to concurrent metabolic parameters. Results suggest interrelations between neural, cognitive, and metabolic parameters.
Background Phenylketonuria (PKU) is an inborn error of metabolism affecting the conversion of phenylalanine (Phe) into tyrosine. Previous research has found cognitive and functional brain alterations in individuals with PKU even if treated early. However, little is known about working memory processing and its association with task performance and metabolic parameters. The aim of the present study was to examine neural correlates of working memory and its association with metabolic parameters in early-treated adults with PKU. Methods This cross-sectional study included 20 early-treated adults with PKU (mean age: 31.4 years ± 9.0) and 40 healthy controls with comparable age, sex, and education (mean age: 29.8 years ± 8.2). All participants underwent functional magnetic resonance imaging (fMRI) of working memory to evaluate the fronto-parietal working memory network. Fasting blood samples were collected from the individuals with PKU to acquire a concurrent plasma amino acid profile, and retrospective Phe concentrations were obtained to estimate an index of dietary control. Results On a cognitive level, early-treated adults with PKU displayed significantly lower accuracy but comparable reaction time in the working memory task compared to the control group. Whole-brain analyses did not reveal differences in working memory-related neural activation between the groups. Exploratory region-of-interest (ROI) analyses indicated reduced neural activation in the left and right middle frontal gyri and the right superior frontal gyrus in the PKU group compared to the control group. However, none of the ROI analyses survived correction for multiple comparisons. Neural activation was related to concurrent Phe, tyrosine, and tryptophan concentrations but not to retrospective Phe concentrations. Conclusion In early-treated adults with PKU, cognitive performance and neural activation are slightly altered, a result that is partly related to metabolic parameters. This study offers a rare insight into the complex interplay between metabolic parameters, neural activation, and cognitive performance in a sample of individuals with PKU.
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Affiliation(s)
- Stephanie Abgottspon
- Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism, Inselspital, Bern University Hospital and University of Bern, Switzerland; Graduate School for Health Sciences, University of Bern, Switzerland; Translational Imaging Center (TIC), Swiss Institute for Translational and Entrepreneurial Medicine, Bern, Switzerland
| | - Raphaela Muri
- Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism, Inselspital, Bern University Hospital and University of Bern, Switzerland; Graduate School for Health Sciences, University of Bern, Switzerland; Support Center for Advanced Neuroimaging (SCAN), Institute of Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital and University of Bern, Switzerland; Translational Imaging Center (TIC), Swiss Institute for Translational and Entrepreneurial Medicine, Bern, Switzerland
| | - Shawn E Christ
- Department of Psychological Sciences, University of Missouri, Columbia, MO, USA
| | - Michel Hochuli
- Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism, Inselspital, Bern University Hospital and University of Bern, Switzerland
| | - Piotr Radojewski
- Support Center for Advanced Neuroimaging (SCAN), Institute of Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital and University of Bern, Switzerland; Translational Imaging Center (TIC), Swiss Institute for Translational and Entrepreneurial Medicine, Bern, Switzerland
| | - Roman Trepp
- Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism, Inselspital, Bern University Hospital and University of Bern, Switzerland; Translational Imaging Center (TIC), Swiss Institute for Translational and Entrepreneurial Medicine, Bern, Switzerland
| | - Regula Everts
- Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism, Inselspital, Bern University Hospital and University of Bern, Switzerland; Division of Neuropaediatrics, Development and Rehabilitation, Inselspital Bern, Children's University Hospital, Bern, Switzerland; Translational Imaging Center (TIC), Swiss Institute for Translational and Entrepreneurial Medicine, Bern, Switzerland.
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Klaassen K, Djordjevic M, Skakic A, Kecman B, Drmanac R, Pavlovic S, Stojiljkovic M. Untreated PKU patients without intellectual disability: SHANK gene family as a candidate modifier. Mol Genet Metab Rep 2021; 29:100822. [PMID: 34900593 PMCID: PMC8639809 DOI: 10.1016/j.ymgmr.2021.100822] [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: 08/23/2021] [Revised: 11/08/2021] [Accepted: 11/09/2021] [Indexed: 11/06/2022] Open
Abstract
Phenylketonuria (PKU) is an inborn error of metabolism caused by variants in the phenylalanine hydroxylase (PAH) gene and it is characterized by excessively high levels of phenylalanine in body fluids. PKU is a paradigm for a genetic disease that can be treated and majority of developed countries have a population-based newborn screening. Thus, the combination of early diagnosis and immediate initiation of treatment has resulted in normal intelligence for treated PKU patients. Although PKU is a monogenic disease, decades of research and clinical practice have shown that the correlation between the genotype and corresponding phenotype is not simple at all. Attempts have been made to discover modifier genes for PKU cognitive phenotype but without any success so far. We conducted whole genome sequencing of 4 subjects from unrelated non-consanguineous families who presented with pathogenic mutations in the PAH gene, high blood phenylalanine concentrations and near-normal cognitive development despite no treatment. We used cross sample analysis to select genes common for more than one patient. Thus, the SHANK gene family emerged as the only relevant gene family with variants detected in 3 of 4 analyzed patients. We detected two novel variants, p.Pro1591Ala in SHANK1 and p.Asp18Asn in SHANK2, as well as SHANK2:p.Gly46Ser, SHANK2:p.Pro1388_Phe1389insLeuPro and SHANK3:p.Pro1716Thr variants that were previously described. Computational analysis indicated that the identified variants do not abolish the function of SHANK proteins. However, changes in posttranslational modifications of SHANK proteins could influence functioning of the glutamatergic synapses, cytoskeleton regulation and contribute to maintaining optimal synaptic density and number of dendritic spines. Our findings are linking SHANK gene family and brain plasticity in PKU for the first time. We hypothesize that variant SHANK proteins maintain optimal synaptic density and number of dendritic spines under high concentrations of phenylalanine and could have protective modifying effect on cognitive development of PKU patients.
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Affiliation(s)
- K Klaassen
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Belgrade, Serbia
| | - M Djordjevic
- Mother and Child Health Care Institute of Serbia "Dr Vukan Cupic", Belgrade, Serbia.,School of Medicine, University of Belgrade, Belgrade, Serbia
| | - A Skakic
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Belgrade, Serbia
| | - B Kecman
- Mother and Child Health Care Institute of Serbia "Dr Vukan Cupic", Belgrade, Serbia
| | - R Drmanac
- Complete Genomics Incorporated, San Jose, California 95134, USA.,MGI, BGI-Shenzhen, Shenzhen 518083, China.,BGI-Shenzhen, Shenzhen 518083, China
| | - S Pavlovic
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Belgrade, Serbia
| | - M Stojiljkovic
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Belgrade, Serbia
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22
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van Wegberg AMJ, Trefz F, Gizewska M, Ahmed S, Chabraoui L, Zaki MS, Maillot F, van Spronsen FJ. Undiagnosed Phenylketonuria Can Exist Everywhere: Results From an International Survey. J Pediatr 2021; 239:231-234.e2. [PMID: 34474089 DOI: 10.1016/j.jpeds.2021.08.070] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 07/30/2021] [Accepted: 08/24/2021] [Indexed: 11/22/2022]
Abstract
Many countries do not have a newborn screening (NBS) program, and immigrants from such countries are at risk for late diagnosis of phenylketonuria (PKU). In this international survey, 52 of 259 patients (20%) with late diagnosed PKU were immigrants, and 145 of the 259 (55%) were born before NBS or in a location without NBS.
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Affiliation(s)
- Annemiek M J van Wegberg
- Division of Metabolic Diseases, Beatrix Children's Hospital, University Medical Center Groningen, Groningen, The Netherlands
| | - Friedrich Trefz
- Dietmar Hopp Metabolic Center, University Children's Hospital, Heidelberg, Germany
| | - Maria Gizewska
- Department of Pediatrics, Endocrinology, Diabetology, Metabolic Diseases, and Cardiology of the Developmental Age, Pomeranian Medical University, Szczecin, Poland
| | - Sibtain Ahmed
- Section of Chemical Pathology, Department of Pathology and Laboratory Medicine, Aga Khan University, Karachi, Pakistan
| | - Layachi Chabraoui
- Central Laboratory of Biochemistry, University Hospital Ibn Sina of Rabat, Rabat, Morocco; Faculty of Pharmacy, University Euromed of Fez, Fez, Morocco
| | - Maha S Zaki
- Human Genetics and Genome Research Division, Clinical Genetics Department, National Research Center, Cairo, Egypt
| | - François Maillot
- Internal Medicine Department, University Hospital of Tours, UMR INSERM 1253 "iBrain", Tours, France
| | - Francjan J van Spronsen
- Division of Metabolic Diseases, Beatrix Children's Hospital, University Medical Center Groningen, Groningen, The Netherlands.
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23
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Mainka T, Fischer JF, Huebl J, Jung A, Lier D, Mosejova A, Skorvanek M, de Koning TJ, Kühn AA, Freisinger P, Ziagaki A, Ganos C. The neurological and neuropsychiatric spectrum of adults with late-treated phenylketonuria. Parkinsonism Relat Disord 2021; 89:167-175. [PMID: 34391119 DOI: 10.1016/j.parkreldis.2021.06.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 06/02/2021] [Accepted: 06/16/2021] [Indexed: 11/16/2022]
Abstract
INTRODUCTION Phenylketonuria (PKU) is a rare, treatable inborn error of metabolism with frequent neurological and neuropsychiatric complications, especially in undiagnosed or insufficiently treated individuals. Given the wide range of clinical presentations and the importance of treatment implications, we here delineate the neurological and neuropsychiatric symptom spectrum in a large cohort of previously unreported adults with late-treated PKU. METHODS We consecutively evaluated late-treated PKU cases and pooled clinical and paraclinical data, including video-material, from three centers with expertise in complex movement disorders, inborn errors of metabolism and pediatrics. RESULTS 26 individuals were included (10 females, median age 52 years). Developmental delay and intellectual disability were omnipresent with severe impairment of expressive communication noted in 50% of cases. Movement disorders were prevalent (77%), including tremor (38%, mostly postural), stereotypies (38%), and tics (19%). One case had neurodegenerative levodopa-responsive parkinsonism. Mild ataxia was noted in 54% of cases and 31% had a history of seizures. Neuropsychiatric characteristics included obsessive-compulsive (35%) and self-injurious behaviors (31%), anxiety (27%), depression (19%) and features compatible with those observed in individuals with autism spectrum disorder (19%). Neuroimaging revealed mild white matter changes. Adherence to dietary treatment was inconsistent in the majority of cases, particularly throughout adolescence. CONCLUSION A history of movement disorders, particularly tremor, stereotypies and tics, in the presence of developmental delay, intellectual disability and neuropsychiatric features, such as obsessive-compulsive and self-injurious behaviors in adults should prompt the diagnostic consideration of PKU. Initiation and adherence to (dietary) treatment can ameliorate the severity of these symptoms.
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Affiliation(s)
- Tina Mainka
- Department of Neurology, Charité University Medicine Berlin, Berlin, Germany; Berlin Institute of Health, Berlin, Germany
| | | | - Julius Huebl
- Department of Neurology, Charité University Medicine Berlin, Berlin, Germany; Department of Neurology, Klinikum Bogenhausen, Städtisches Klinikum München GmbH, Munich, Germany
| | - Alexandra Jung
- Interdisciplinary Center of Metabolism: Endocrinology, Diabetes and Metabolism, University-Medicine Berlin, Campus Virchow-Klinikum, Germany
| | - Dinah Lier
- Department of Pediatrics, Klinikum Reutlingen, Reutlingen, Germany
| | - Alexandra Mosejova
- Department of Neurology, P.J. Safarik University, Košice, Slovakia; Department of Neurology, University Hospital L. Pasteur, Košice, Slovakia
| | - Matej Skorvanek
- Department of Neurology, P.J. Safarik University, Košice, Slovakia; Department of Neurology, University Hospital L. Pasteur, Košice, Slovakia
| | - Tom J de Koning
- Department of Neurology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands; Pediatrics, Department of Clinical Sciences, Lund University, Sweden
| | - Andrea A Kühn
- Department of Neurology, Charité University Medicine Berlin, Berlin, Germany
| | - Peter Freisinger
- Department of Pediatrics, Klinikum Reutlingen, Reutlingen, Germany
| | - Athanasia Ziagaki
- Interdisciplinary Center of Metabolism: Endocrinology, Diabetes and Metabolism, University-Medicine Berlin, Campus Virchow-Klinikum, Germany
| | - Christos Ganos
- Department of Neurology, Charité University Medicine Berlin, Berlin, Germany.
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Abstract
Phenylketonuria (PKU; also known as phenylalanine hydroxylase (PAH) deficiency) is an autosomal recessive disorder of phenylalanine metabolism, in which especially high phenylalanine concentrations cause brain dysfunction. If untreated, this brain dysfunction results in severe intellectual disability, epilepsy and behavioural problems. The prevalence varies worldwide, with an average of about 1:10,000 newborns. Early diagnosis is based on newborn screening, and if treatment is started early and continued, intelligence is within normal limits with, on average, some suboptimal neurocognitive function. Dietary restriction of phenylalanine has been the mainstay of treatment for over 60 years and has been highly successful, although outcomes are still suboptimal and patients can find the treatment difficult to adhere to. Pharmacological treatments are available, such as tetrahydrobiopterin, which is effective in only a minority of patients (usually those with milder PKU), and pegylated phenylalanine ammonia lyase, which requires daily subcutaneous injections and causes adverse immune responses. Given the drawbacks of these approaches, other treatments are in development, such as mRNA and gene therapy. Even though PAH deficiency is the most common defect of amino acid metabolism in humans, brain dysfunction in individuals with PKU is still not well understood and further research is needed to facilitate development of pathophysiology-driven treatments.
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Affiliation(s)
- Francjan J van Spronsen
- Beatrix Children's Hospital, University Medical Centre Groningen, University of Groningen, Groningen, Netherlands.
| | - Nenad Blau
- University Children's Hospital in Zurich, Zurich, Switzerland
| | - Cary Harding
- Department of Molecular and Medical Genetics and Department of Pediatrics, Oregon Health & Science University, Oregon, USA
| | | | - Nicola Longo
- Department of Pediatrics, University of Utah, Salt Lake City, Utah, USA
| | - Annet M Bosch
- University of Amsterdam, Department of Pediatrics, Division of Metabolic Disorders, Emma Children's Hospital, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
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25
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Hozyasz KK, Żółkowska J, Chyż K. Comparison of phenylalanine tolerance in singleton and twin pregnancies in patients with phenylketonuria. J Int Med Res 2021; 48:300060520934623. [PMID: 32962492 PMCID: PMC7520934 DOI: 10.1177/0300060520934623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Objectives Empirical determination of phenylalanine (Phe) tolerance in patients with
phenylketonuria (PKU) relies on frequent assessment of blood Phe
concentrations in relation to Phe intake from detailed meal records. This
study aimed to determine Phe tolerance in twin pregnancies. Methods The reviewed cases included three women with PKU who each had a singleton and
twin pregnancy (i.e., they were pregnant twice). All patients were under
regular supervision to maintain Phe concentrations in a steady state and
determine safe Phe intake. Restriction of Phe in the patient’s diet was
determined depending on the amount of Phe intake, which allowed for stable
blood Phe concentrations within the target range. Results In all three patients with PKU, the ratio of Phe tolerance during the course
of the twin and singleton pregnancies was <1 for most of the pregnancy.
The ratio of the increase in Phe tolerance between 29 and 34 weeks of
gestation and that between 15 and 28 weeks of gestation was 0.66 and 1.17,
0.51 and 0.14, and 0.76 and 1.42 in the twin and singleton pairs of
pregnancies, respectively. Conclusions Our study shows that Phe tolerance in a twin pregnancy is not greater than
that in a singleton pregnancy.
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Affiliation(s)
- Kamil Konrad Hozyasz
- Institute of Health Sciences, State School of Higher Education, Biała Podlaska, Poland
| | | | - Katarzyna Chyż
- PKU Polyclinic, Institute of Mother and Child, Warsaw, Poland
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26
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The rs113883650 variant of SLC7A5 (LAT1) gene may alter brain phenylalanine content in PKU. Mol Genet Metab Rep 2021; 27:100751. [PMID: 33868932 PMCID: PMC8040326 DOI: 10.1016/j.ymgmr.2021.100751] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 03/25/2021] [Accepted: 03/26/2021] [Indexed: 12/13/2022] Open
Abstract
Functional alteration of the LAT1 amino acid transporter may be responsible for interindividual differences in cerebral phenylalanine content and the lack of intellectual disability in some patients with untreated phenylketonuria. We assessed the effect of the common variant rs113883650 of the SLC7A5 (LAT1) gene on brain phenylalanine content, as measured with use of magnetic resonance spectroscopy. Our results suggest that the presence of this variant could influence the amount of phenylalanine in the brain.
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27
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Heidari A, Arab M, Damari B. A policy analysis of the national phenylketonuria screening program in Iran. BMC Health Serv Res 2021; 21:120. [PMID: 33546689 PMCID: PMC7863318 DOI: 10.1186/s12913-021-06116-w] [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: 01/18/2020] [Accepted: 07/13/2020] [Indexed: 11/24/2022] Open
Abstract
Background Phenylketonuria (PKU) screening is a public health measure taken to diagnose and treat the patients with PKU to prevent severe neurological disorders in them. The present study was aimed at analyzing the policies of the national PKU screening (NaPS) program in Iran. Methods PKU screening program policies were analyzed in compliance with the policy triangle model. Document review and 38 semi-structured interviews were used for data collection. Document review data were analyzed using content analysis, and interview data were analyzed using framework analysis. Results The national PKU screening (NaPS) program was a decision made at the genetics department of Ministry of Health and Medical Education (MOHME) in Iran. Many internal and external stakeholders were involved in it and valid evidence was used to formulate the policies. Despite some opposition and insufficient support, the program was implemented due to the continuous persistence of parents, interested executives, formulated valid content and a top-down approach. The main barriers included rapid substitution of managers, shortage of Phe-free milk, little awareness of patients’ families, social stigma, and inadequate co-operation of some hospital administrators. Conclusions The policy triangle framework contributed to explaining the different components of the PKU screening program. A successful PKU screening program requires more stability of senior managers in MOHME, enough human resources and Phe-free milk, educating patients’ families, and commitment of hospitals administrators. Meanwhile, all the stakeholders need to be involved in the program effectively. Supplementary Information The online version contains supplementary material available at 10.1186/s12913-021-06116-w.
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Affiliation(s)
- Alireza Heidari
- Health Management and Social Development Research Center, Golestan University of Medical Sciences (GOUMS), Golha Alley, Gorgan, Iran.
| | - Mohammad Arab
- Department of Management and Health Economic, School of Public Health, Tehran University of Medical Sciences (TUMS), Tehran, Iran
| | - Behzad Damari
- Governance and Health Department, Neuroscience Institute, Tehran University of Medical Sciences (TUMS), Tehran, Iran
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28
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Lowe TB, DeLuca J, Arnold G. Neurocognitive, neuropsychiatric, and neurological outcomes associated with phenylalanine hydroxylase deficiency: Assessment considerations for nurse practitioners. J SPEC PEDIATR NURS 2021; 26:e12312. [PMID: 32956570 DOI: 10.1111/jspn.12312] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 05/11/2020] [Accepted: 09/03/2020] [Indexed: 11/30/2022]
Abstract
PURPOSE The purpose of this article is to review literature for neurocognitive, neuropsychiatric, neurological complications associated with phenylalanine hydroxylase (PAH) deficiency. The goal is to familiarize nurse practitioners with treatment and monitoring guidelines for persons living with the disorder. CONCLUSIONS Appropriate treatment can maximize neurocognitive and neuropsychiatric outcomes. PRACTICE IMPLICATIONS Nurse practitioners can help persons with PAH deficiency through education and providing appropriate referrals and by supporting disease-specific treatment.
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Affiliation(s)
- Tracy B Lowe
- Healthcare Genetics, Clemson University, Clemson, South Carolina, USA
| | - Jane DeLuca
- Clemson University, Clemson, South Carolina, USA
| | - Georgianne Arnold
- Medical Genetics Clinical Research, UPMC Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA
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29
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Koppes EA, Redel BK, Johnson MA, Skvorak KJ, Ghaloul-Gonzalez L, Yates ME, Lewis DW, Gollin SM, Wu YL, Christ SE, Yerle M, Leshinski A, Spate LD, Benne JA, Murphy SL, Samuel MS, Walters EM, Hansen SA, Wells KD, Lichter-Konecki U, Wagner RA, Newsome JT, Dobrowolski SF, Vockley J, Prather RS, Nicholls RD. A porcine model of phenylketonuria generated by CRISPR/Cas9 genome editing. JCI Insight 2020; 5:141523. [PMID: 33055427 PMCID: PMC7605535 DOI: 10.1172/jci.insight.141523] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 09/17/2020] [Indexed: 12/17/2022] Open
Abstract
Phenylalanine hydroxylase-deficient (PAH-deficient) phenylketonuria (PKU) results in systemic hyperphenylalaninemia, leading to neurotoxicity with severe developmental disabilities. Dietary phenylalanine (Phe) restriction prevents the most deleterious effects of hyperphenylalaninemia, but adherence to diet is poor in adult and adolescent patients, resulting in characteristic neurobehavioral phenotypes. Thus, an urgent need exists for new treatments. Additionally, rodent models of PKU do not adequately reflect neurocognitive phenotypes, and thus there is a need for improved animal models. To this end, we have developed PAH-null pigs. After selection of optimal CRISPR/Cas9 genome-editing reagents by using an in vitro cell model, zygote injection of 2 sgRNAs and Cas9 mRNA demonstrated deletions in preimplantation embryos, with embryo transfer to a surrogate leading to 2 founder animals. One pig was heterozygous for a PAH exon 6 deletion allele, while the other was compound heterozygous for deletions of exon 6 and of exons 6-7. The affected pig exhibited hyperphenylalaninemia (2000-5000 μM) that was treatable by dietary Phe restriction, consistent with classical PKU, along with juvenile growth retardation, hypopigmentation, ventriculomegaly, and decreased brain gray matter volume. In conclusion, we have established a large-animal preclinical model of PKU to investigate pathophysiology and to assess new therapeutic interventions.
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Affiliation(s)
- Erik A Koppes
- Division of Medical Genetics, Department of Pediatrics, University of Pittsburgh School of Medicine, and Universityof Pittsburgh Medical Center (UPMC) Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Bethany K Redel
- Division ofAnimal Sciences, College of Agriculture, Food and Natural Resources, University of Missouri, Columbia, Missouri, USA.,National Swine Research and Resource Center (NSRRC), College of Veterinary Medicine, University of Missouri, Columbia, Missouri, USA
| | - Marie A Johnson
- Division of Medical Genetics, Department of Pediatrics, University of Pittsburgh School of Medicine, and Universityof Pittsburgh Medical Center (UPMC) Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Kristen J Skvorak
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Lina Ghaloul-Gonzalez
- Division of Medical Genetics, Department of Pediatrics, University of Pittsburgh School of Medicine, and Universityof Pittsburgh Medical Center (UPMC) Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA.,Department of Human Genetics, University of Pittsburgh Graduate School of Public Health, Pittsburgh, Pennsylvania, USA
| | - Megan E Yates
- Division of Medical Genetics, Department of Pediatrics, University of Pittsburgh School of Medicine, and Universityof Pittsburgh Medical Center (UPMC) Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Dale W Lewis
- Department of Human Genetics, University of Pittsburgh Graduate School of Public Health, Pittsburgh, Pennsylvania, USA
| | - Susanne M Gollin
- Department of Human Genetics, University of Pittsburgh Graduate School of Public Health, Pittsburgh, Pennsylvania, USA
| | - Yijen L Wu
- Department of Developmental Biology, University of Pittsburgh, and UPMC Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Shawn E Christ
- Department of Psychological Sciences, University of Missouri, Columbia, Missouri, USA
| | - Martine Yerle
- GenPhySE, Université de Toulouse, INRAE, ENVT, 31326, Castanet-Tolosan, France
| | - Angela Leshinski
- Division of Medical Genetics, Department of Pediatrics, University of Pittsburgh School of Medicine, and Universityof Pittsburgh Medical Center (UPMC) Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Lee D Spate
- Division ofAnimal Sciences, College of Agriculture, Food and Natural Resources, University of Missouri, Columbia, Missouri, USA.,National Swine Research and Resource Center (NSRRC), College of Veterinary Medicine, University of Missouri, Columbia, Missouri, USA
| | - Joshua A Benne
- National Swine Research and Resource Center (NSRRC), College of Veterinary Medicine, University of Missouri, Columbia, Missouri, USA
| | - Stephanie L Murphy
- National Swine Research and Resource Center (NSRRC), College of Veterinary Medicine, University of Missouri, Columbia, Missouri, USA
| | - Melissa S Samuel
- Division ofAnimal Sciences, College of Agriculture, Food and Natural Resources, University of Missouri, Columbia, Missouri, USA.,National Swine Research and Resource Center (NSRRC), College of Veterinary Medicine, University of Missouri, Columbia, Missouri, USA
| | - Eric M Walters
- Division ofAnimal Sciences, College of Agriculture, Food and Natural Resources, University of Missouri, Columbia, Missouri, USA.,National Swine Research and Resource Center (NSRRC), College of Veterinary Medicine, University of Missouri, Columbia, Missouri, USA
| | - Sarah A Hansen
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, Missouri, USA
| | - Kevin D Wells
- Division ofAnimal Sciences, College of Agriculture, Food and Natural Resources, University of Missouri, Columbia, Missouri, USA.,National Swine Research and Resource Center (NSRRC), College of Veterinary Medicine, University of Missouri, Columbia, Missouri, USA
| | - Uta Lichter-Konecki
- Division of Medical Genetics, Department of Pediatrics, University of Pittsburgh School of Medicine, and Universityof Pittsburgh Medical Center (UPMC) Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Robert A Wagner
- Division of Laboratory Animal Resources, Office of Research, Health Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Joseph T Newsome
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.,Division of Laboratory Animal Resources, Office of Research, Health Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Steven F Dobrowolski
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Jerry Vockley
- Division of Medical Genetics, Department of Pediatrics, University of Pittsburgh School of Medicine, and Universityof Pittsburgh Medical Center (UPMC) Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA.,Department of Human Genetics, University of Pittsburgh Graduate School of Public Health, Pittsburgh, Pennsylvania, USA
| | - Randall S Prather
- Division ofAnimal Sciences, College of Agriculture, Food and Natural Resources, University of Missouri, Columbia, Missouri, USA.,National Swine Research and Resource Center (NSRRC), College of Veterinary Medicine, University of Missouri, Columbia, Missouri, USA
| | - Robert D Nicholls
- Division of Medical Genetics, Department of Pediatrics, University of Pittsburgh School of Medicine, and Universityof Pittsburgh Medical Center (UPMC) Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA
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Cognitive Outcomes and Relationships with Phenylalanine in Phenylketonuria: A Comparison between Italian and English Adult Samples. Nutrients 2020; 12:nu12103033. [PMID: 33022955 PMCID: PMC7599948 DOI: 10.3390/nu12103033] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 09/23/2020] [Accepted: 09/24/2020] [Indexed: 02/06/2023] Open
Abstract
We aimed to assess if the same cognitive batteries can be used cross-nationally to monitor the effect of Phenylketonuria (PKU). We assessed whether a battery, previously used with English adults with PKU (AwPKU), was also sensitive to impairments in Italian AwPKU. From our original battery, we selected a number of tasks that comprehensively assessed visual attention, visuo-motor coordination, executive functions (particularly, reasoning, planning, and monitoring), sustained attention, and verbal and visual memory and learning. When verbal stimuli/or responses were involved, stimuli were closely matched between the two languages for psycholinguistic variables. We administered the tasks to 19 Italian AwPKU and 19 Italian matched controls and compared results from with 19 English AwPKU and 19 English matched controls selected from a previously tested cohort. Participant election was blind to cognitive performance and metabolic control, but participants were closely matched for age and education. The Italian AwPKU group had slightly worse metabolic control but showed levels of performance and patterns of impairment similar to the English AwPKU group. The Italian results also showed extensive correlations between adult cognitive measures and metabolic measures across the life span, both in terms of Phenylalanine (Phe) levels and Phe fluctuations, replicating previous results in English. These results suggest that batteries with the same and/or matched tasks can be used to assess cognitive outcomes across countries allowing results to be compared and accrued. Future studies should explore potential differences in metabolic control across countries to understand what variables make metabolic control easier to achieve.
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31
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Halil K, Meryem K. Plasma amino acid levels in a cohort of patients in Turkey with classical phenylketonuria. ASIAN BIOMED 2020. [DOI: 10.1515/abm-2020-0009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Background
In patients with phenylketonuria, the central nervous system is adversely affected by noncompliance with diet. The levels of phenylalanine and many different amino acids (AAs) in the plasma of patients with phenylketonuria can be measured simultaneously.
Objectives
To measure the blood plasma levels of neurotransmitter AAs in a cohort of patients in Sanliurfa province, Turkey, with phenylketonuria for use as a support parameter for the follow-up of patients.
Methods
The phenylketonurics that we followed (n = 100) were divided into 2 groups according to their compliance with their dietary treatment. Plasma AA analysis results of phenylketonurics were compared with those of healthy children in a control group (n = 50).
Results
In the diet incompliant group (n = 56), the mean levels of γ-aminobutyric acid (GABA; 0.96 ± 1.07 μmol/L) and glycine (305.1 ± 105.19 μmol/L) were significantly higher than those in the diet compliant group (n = 44; GABA P = 0.005, glycine P < 0.001) and in the control group (GABA and glycine P < 0.001), whereas the mean levels of glutamic acid (39.01 ± 22.94 μmol/L) and asparagine (39.3 ± 16.89 μmol/L) were lower (P < 0.001) in the diet incompliant group. A positive correlation was observed between the levels of phenylalanine and GABA and glycine. A negative relationship was found between the levels of phenylalanine and glutamic acid and asparagine.
Conclusions
A relationship exists between the levels of plasma phenylalanine in a cohort of phenylketonurics in Sanliurfa province, Turkey, and the levels of some excitatory and inhibitory AAs. Excitatory and inhibitory AA levels in plasma may be used as support parameters in the follow-up of patients with phenylketonuria.
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Affiliation(s)
- Kazanasmaz Halil
- Department of Pediatrics, Faculty of Medicine , Harran University , Sanliurfa , Turkey
| | - Karaca Meryem
- Department of Pediatric Metabolism Disorders, Faculty of Medicine , Harran University , Sanliurfa , Turkey
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Levy H, Lamppu D, Anastosoaie V, Baker JL, DiBona K, Hawthorne S, Lindenberger J, Kinch D, Seymour A, McIlduff M, Watling S, Vockley J. 5-year retrospective analysis of patients with phenylketonuria (PKU) and hyperphenylalaninemia treated at two specialized clinics. Mol Genet Metab 2020; 129:177-185. [PMID: 31883647 DOI: 10.1016/j.ymgme.2019.12.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 12/05/2019] [Accepted: 12/08/2019] [Indexed: 11/23/2022]
Abstract
BACKGROUND Phenylketonuria (PKU) is an autosomal recessive disease caused by mutations in the PAH gene, resulting in deficiency of phenylalanine hydroxylase (PAH), an enzyme that converts phenylalanine (Phe) to tyrosine (Tyr). The purpose of this study was to capture real-world data associated with managing PKU under current standard of care and to characterize a representative population for a planned gene therapy trial. METHODS A retrospective chart review was conducted at two U.S. clinics for individuals 10-40 years old diagnosed with PKU-related hyperphenylalaninemia (HPA). Demographics, medical history, treatments and blood Phe data were collected from electronic medical records spanning a five-year period ending in November 2017. RESULTS 152 patients were enrolled (65.8% had classical PKU). Although >95% of patients were prescribed a Phe-restricted diet, blood Phe concentrations remained substantially elevated, particularly in patients diagnosed with classical PKU. As the Phe threshold was lowered (Phe < 600, 360, 120 or 30 μmol/L), the number of patients with consecutive lab values below the threshold decreased, suggesting that many patients' Phe levels are inadequately controlled. 62.5% of patients were reported as having a history of at least one neuropsychiatric comorbidity, and adults were more likely than adolescents (69.5% vs. 54.3%). 92 of 98 PAH genotypes collected were distinct mutations; the 6 null-null genotypes were associated with classical PKU. Overall the demographics and clinical data were consistent across both sites. CONCLUSION Despite dietary restrictions, mean Phe concentrations were > 360 μmol/L (a level considered well-controlled based on current U.S. treatment guidelines) for mild, moderate, and classical PKU patients. There remains an unmet need for therapies to control Phe concentrations.
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Affiliation(s)
- Harvey Levy
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
| | | | - Vera Anastosoaie
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA
| | - Jennifer L Baker
- Division Medical Genetics, Department of Pediatrics, University of Pittsburgh School of Medicine, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA, USA
| | - Kevin DiBona
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA
| | - Sarah Hawthorne
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA
| | - Jessica Lindenberger
- Division Medical Genetics, Department of Pediatrics, University of Pittsburgh School of Medicine, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA, USA
| | | | | | - Mark McIlduff
- Boston Biomedical Associates, LLC, Marlborough, MA, USA
| | | | - Jerry Vockley
- Division Medical Genetics, Department of Pediatrics, University of Pittsburgh School of Medicine, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA, USA.
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Cannet C, Pilotto A, Rocha JC, Schäfer H, Spraul M, Berg D, Nawroth P, Kasperk C, Gramer G, Haas D, Piel D, Kölker S, Hoffmann G, Freisinger P, Trefz F. Lower plasma cholesterol, LDL-cholesterol and LDL-lipoprotein subclasses in adult phenylketonuria (PKU) patients compared to healthy controls: results of NMR metabolomics investigation. Orphanet J Rare Dis 2020; 15:61. [PMID: 32106880 PMCID: PMC7047385 DOI: 10.1186/s13023-020-1329-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 02/07/2020] [Indexed: 12/22/2022] Open
Abstract
Background Phenylketonuria (PKU; OMIM#261600) is a rare metabolic disorder caused by mutations in the phenylalanine hydroxylase (PAH) gene resulting in high phenylalanine (Phe) in blood and brain. If not treated early this results in intellectual disability, behavioral and psychiatric problems, microcephaly, motor deficits, eczematous rash, autism, seizures, and developmental problems. There is a controversial discussion of whether patients with PKU have an additional risk for atherosclerosis due to interference of Phe with cholesterol synthesis and LDL-cholesterol regulation. Since cholesterol also plays a role in membrane structure and myelination, better insight into the clinical significance of the impact of Phe on lipoprotein metabolism is desirable. In 22 treated PKU patients (mean age 38.7 years) and 14 healthy controls (mean age 35.2 years), we investigated plasma with NMR spectroscopy and quantified 105 lipoprotein parameters (including lipoprotein subclasses) and 24 low molecular weight parameters. Analysis was performed on a 600 MHz Bruker AVANCE IVDr spectrometer as previously described. Results Concurrent plasma Phe in PKU patients showed a wide range with a mean of 899 μmol/L (50–1318 μmol/L). Total cholesterol and LDL-cholesterol were significantly lower in PKU patients versus controls: 179.4 versus 200.9 mg/dL (p < 0.02) and 79.5 versus 104.1 mg/dL (p < 0.0038), respectively. PKU patients also had lower levels of 22 LDL subclasses with the greatest differences in LDL2 Apo-B, LDL2 Particle Number, LDL2-phospholipids, and LDL2-cholesterol (p < 0.0001). There was a slight negative correlation of total cholesterol and LDL-cholesterol with concurrent Phe level. VLDL5-free cholesterol, VLDL5-cholesterol, VLDL5-phospholipids, and VLDL4-free cholesterol showed a significant (p < 0.05) negative correlation with concurrent Phe level. There was no difference in HDL and their subclasses between PKU patients and controls. Tyrosine, glutamine, and creatinine were significantly lower in PKU patients compared to controls, while citric and glutamic acids were significantly higher. Conclusions Using NMR spectroscopy, a unique lipoprotein profile in PKU patients can be demonstrated which mimics a non-atherogenic profile as seen in patients treated by statins.
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Affiliation(s)
| | - Andrea Pilotto
- Department of Neurodegeneration, Hertie Institute of Clinical Brain Research, University of Tübingen, Tübingen, Germany.,Neurology Unit, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy.,Parkinson's Disease Rehabilitation Centre, FERB ONLUS S, Isidoro Hospital, Trescore Balneario, Italy
| | - Júlio César Rocha
- Center for Health Technology and Services Research (CINTESIS), Porto, Portugal.,Nutrition & Metabolism, NOVA Medical School, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal
| | | | | | - Daniela Berg
- Department of Neurology, University-Hospital-Schleswig-Holstein, Christian-Albrechts-University, Kiel, Germany
| | - Peter Nawroth
- Department of Endocrinology and Metabolism, University Hospital, Heidelberg, Germany
| | - Christian Kasperk
- Department of Endocrinology and Metabolism, University Hospital, Heidelberg, Germany
| | - Gwendolyn Gramer
- Department of Pediatrics, Centre for Pediatric and Adolescent Medicine, Division of Neuropaediatrics and Metabolic Medicine, University Hospital, Heidelberg, Germany
| | - Dorothea Haas
- Department of Pediatrics, Centre for Pediatric and Adolescent Medicine, Division of Neuropaediatrics and Metabolic Medicine, University Hospital, Heidelberg, Germany
| | - David Piel
- Pediatrics, Reutlingen Hospital, Reutlingen, Germany
| | - Stefan Kölker
- Department of Pediatrics, Centre for Pediatric and Adolescent Medicine, Division of Neuropaediatrics and Metabolic Medicine, University Hospital, Heidelberg, Germany
| | - Georg Hoffmann
- Department of Pediatrics, Centre for Pediatric and Adolescent Medicine, Division of Neuropaediatrics and Metabolic Medicine, University Hospital, Heidelberg, Germany
| | | | - Friedrich Trefz
- Department of Pediatrics, Centre for Pediatric and Adolescent Medicine, Division of Neuropaediatrics and Metabolic Medicine, University Hospital, Heidelberg, Germany. .,Metabolic Consulting, Reutlingen, Germany.
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Moro CA, Hanna-Rose W. Animal Model Contributions to Congenital Metabolic Disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1236:225-244. [PMID: 32304075 PMCID: PMC8404832 DOI: 10.1007/978-981-15-2389-2_9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Genetic model systems allow researchers to probe and decipher aspects of human disease, and animal models of disease are frequently specifically engineered and have been identified serendipitously as well. Animal models are useful for probing the etiology and pathophysiology of disease and are critical for effective discovery and development of novel therapeutics for rare diseases. Here we review the impact of animal model organism research in three examples of congenital metabolic disorders to highlight distinct advantages of model system research. First, we discuss phenylketonuria research where a wide variety of research fields and models came together to make impressive progress and where a nearly ideal mouse model has been central to therapeutic advancements. Second, we review advancements in Lesch-Nyhan syndrome research to illustrate the role of models that do not perfectly recapitulate human disease as well as the need for multiple models of the same disease to fully investigate human disease aspects. Finally, we highlight research on the GM2 gangliosidoses Tay-Sachs and Sandhoff disease to illustrate the important role of both engineered traditional laboratory animal models and serendipitously identified atypical models in congenital metabolic disorder research. We close with perspectives for the future for animal model research in congenital metabolic disorders.
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Affiliation(s)
- Corinna A Moro
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA
| | - Wendy Hanna-Rose
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA.
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Romani C, Manti F, Nardecchia F, Valentini F, Fallarino N, Carducci C, De Leo S, MacDonald A, Palermo L, Leuzzi V. Adult cognitive outcomes in phenylketonuria: explaining causes of variability beyond average Phe levels. Orphanet J Rare Dis 2019; 14:273. [PMID: 31779649 PMCID: PMC6883518 DOI: 10.1186/s13023-019-1225-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 10/09/2019] [Indexed: 11/10/2022] Open
Abstract
Objective The objective was to deepen the understanding of the causes of individual variability in phenylketonuria (PKU) by investigating which metabolic variables are most important for predicting cognitive outcomes (Phe average vs Phe variation) and by assessing the risk of cognitive impairment associated with adopting a more relaxed approach to the diet than is currently recommended. Method We analysed associations between metabolic and cognitive measures in a mixed sample of English and Italian early-treated adults with PKU (N = 56). Metabolic measures were collected through childhood, adolescence and adulthood; cognitive measures were collected in adulthood. Metabolic measures included average Phe levels (average of median values for each year in a given period) and average Phe variations (average yearly standard deviations). Cognition was measured with IQ and a battery of cognitive tasks. Results Phe variation was as important, if not more important, than Phe average in predicting adult outcomes and contributed independently. Phe variation was particularly detrimental in childhood. Together, childhood Phe variation and adult Phe average predicted around 40% of the variation in cognitive scores. Poor cognitive scores (> 1 SD from controls) occurred almost exclusively in individuals with poor metabolic control and the risk of poor scores was about 30% higher in individuals with Phe values exceeding recommended thresholds. Conclusions Our results provide support for current European guidelines (average Phe value = < 360 μmol/l in childhood; = < 600 μmo/l from 12 years onwards), but they suggest an additional recommendation to maintain stable levels (possibly Phe SD = < 180 μmol/l throughout life). Public significance statements We investigated the relationship between how well people with phenylketonuria control blood Phe throughout their life and their ability to carry out cognitive tasks in adulthood. We found that avoiding blood Phe peaks was as important if not more important that maintaining average low Phe levels. This was particularly essential in childhood. We also found that blood Phe levels above recommended European guidelines was associated with around 30% increase in the risk of poor cognitive outcomes.
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Affiliation(s)
- Cristina Romani
- School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham, England, B4 7ET, UK.
| | - Filippo Manti
- Department of Human Neuroscience - Unit of Child Neurology and Psychiatry, Sapienza University of Rome, Rome, Italy
| | - Francesca Nardecchia
- Department of Human Neuroscience - Unit of Child Neurology and Psychiatry, Sapienza University of Rome, Rome, Italy
| | | | | | - Claudia Carducci
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
| | - Sabrina De Leo
- Department of Clinical Medicine, Policlinico Umberto I, Rome, Italy
| | - Anita MacDonald
- Birmingham Women's and Children's NHS Foundation Trust, Birmingham, UK
| | - Liana Palermo
- Department of Medical and Surgical Sciences, Magna Graecia University of Catanzaro, Catanzaro, Italy
| | - Vincenzo Leuzzi
- Department of Human Neuroscience - Unit of Child Neurology and Psychiatry, Sapienza University of Rome, Rome, Italy
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Untreated PKU Patients without Intellectual Disability: What Do They Teach Us? Nutrients 2019; 11:nu11112572. [PMID: 31731404 PMCID: PMC6893397 DOI: 10.3390/nu11112572] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Revised: 10/16/2019] [Accepted: 10/21/2019] [Indexed: 12/17/2022] Open
Abstract
Phenylketonuria (PKU) management is aimed at preventing neurocognitive and psychosocial dysfunction by keeping plasma phenylalanine concentrations within the recommended target range. It can be questioned, however, whether universal plasma phenylalanine target levels would result in optimal neurocognitive outcomes for all patients, as similar plasma phenylalanine concentrations do not seem to have the same consequences to the brain for each PKU individual. To better understand the inter-individual differences in brain vulnerability to high plasma phenylalanine concentrations, we aimed to identify untreated and/or late-diagnosed PKU patients with near-normal outcome, despite high plasma phenylalanine concentrations, who are still alive. In total, we identified 16 such cases. While intellectual functioning in these patients was relatively unaffected, they often did present other neurological, psychological, and behavioral problems. Thereby, these “unusual” PKU patients show that the classical symptomatology of untreated or late-treated PKU may have to be rewritten. Moreover, these cases show that a lack of intellectual dysfunction despite high plasma phenylalanine concentrations does not necessarily imply that these high phenylalanine concentrations have not been toxic to the brain. Also, these cases may suggest that different mechanisms are involved in PKU pathophysiology, of which the relative importance seems to differ between patients and possibly also with increasing age. Further research should aim to better distinguish PKU patients with respect to their cerebral effects to high plasma phenylalanine concentrations.
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Leuzzi V, Chiarotti F, Nardecchia F, van Vliet D, van Spronsen FJ. Predictability and inconsistencies of cognitive outcome in patients with phenylketonuria and personalised therapy: the challenge for the future guidelines. J Med Genet 2019; 57:145-150. [DOI: 10.1136/jmedgenet-2019-106278] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 07/06/2019] [Accepted: 08/11/2019] [Indexed: 11/04/2022]
Abstract
Phenylketonuria (PKU) is a prototypical model of a neurodevelopmental metabolic disease that follows a cascade of pathological events affecting brain maturation and functioning. Neonatal screening and early treatment have eradicated the classical PKU phenotype in patients with early and continuously treated phenylketonuria (ECTPKU). However, effort is required to optimise the treatment of the disease to minimise the risk of lifelong neurological, cognitive and behavioural impairment, and to solve issues on the variability in clinical outcome that are rather not understood and has yet hampered a more personalised approach to its treatment. The aim of the present review is to focus on the inconsistencies in the clinical outcome of adult patients with ECTPKU unexplained by the biochemical markers adopted for the monitoring of the disease to date. The interindividual variability of clinical outcome in late as well as in early treated patients under similar biochemical control suggests the existence of disease-independent determinants influencing the individual vulnerability to the neurotoxic effect of phenylalanine. This is further supported by the low predictive power of blood phenylalanine on the clinical outcome from the second decade of life onwards. In conclusion, individual vulnerability to the metabolic alterations of PKU contributes to the prognosis of PKU, also in patients with ECTPKU. The biological factors constitutive of this vulnerability are unknown (but have not been the object of many studies so far) and should be the target of further research as prerequisite for a personalised treatment aimed at avoiding burden and costs of overtreatment and clinical consequences and risks of undertreatment in patients with PKU.
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Vockley J, Dobrowolski SF, Arnold GL, Guerrero RB, Derks TGJ, Weinstein DA. Complex patterns of inheritance, including synergistic heterozygosity, in inborn errors of metabolism: Implications for precision medicine driven diagnosis and treatment. Mol Genet Metab 2019; 128:1-9. [PMID: 31358473 PMCID: PMC8931500 DOI: 10.1016/j.ymgme.2019.07.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 07/18/2019] [Accepted: 07/18/2019] [Indexed: 01/03/2023]
Abstract
Inborn errors of metabolism have traditionally been viewed as the quintessential single gene disorders; defects in one gene leads to loss of activity of one enzyme causing a metabolic imbalance and clinical disease. However, reality has never been quite that simple, and the classic "one gene-one enzyme" paradigm has been upended in many ways. Multiple gene defects can lead to the same biochemical phenotype, often with different clinical symptoms. Additionally, different mutations in the same gene can cause variable phenotypes, often most dramatic when a disease can be identified by pre-symptomatic screening. Moreover, response to therapy is not homogeneous across diseases and specific mutations. Perhaps the biggest deviation from traditional monogenic inheritance is in the setting of synergistic heterozygosity, a multigenic inheritance pattern in which mutations in multiple genes in a metabolic pathway lead to sufficient disruption of flux through the pathway, mimicking a monogenic disorder caused by homozygous defects in one gene in that pathway. In addition, widespread adoption of whole exome and whole genome sequencing in medical genetics has led to the realization that individual patients with apparently hybrid phenotypes can have mutations in more than one gene, leading to a mixed genetic disorder. Each of these situations point to a need for as much precision as possible in diagnosing metabolic disease, and it is likely to become increasingly critical to drive therapy. This article examines examples in traditional monogenic disorders that illustrates these points and define inborn errors of metabolism as complex genetic traits on the leading edge of precision medicine.
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Affiliation(s)
- Jerry Vockley
- University of Pittsburgh School of Medicine, Department of Pediatrics, Pittsburgh, PA, United States of America; UPMC Children's Hospital of Pittsburgh, 4401 Penn Avenue, Pittsburgh, PA 15224, United States of America.
| | - Steven F Dobrowolski
- University of Pittsburgh School of Medicine, Department of Pathology, Pittsburgh, PA. UPMC Children's Hospital of Pittsburgh. 4401 Penn Avenue, Pittsburgh, PA 15224, United States of America
| | - Georgianne L Arnold
- University of Pittsburgh School of Medicine, Department of Pediatrics, Pittsburgh, PA, United States of America; UPMC Children's Hospital of Pittsburgh, 4401 Penn Avenue, Pittsburgh, PA 15224, United States of America
| | | | - Terry G J Derks
- Section of Metabolic Diseases, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, PO box 30 001, 9700, RB, Groningen, the Netherlands
| | - David A Weinstein
- Department of Pediatrics, University of Connecticut School of Medicine, Farmington, CT 06030, United States of America; GSD Program, Connecticut Children's Medical Center, Hartford, CT 06106, United States of America
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