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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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Rovelli V, Ercoli V, Dionigi AR, Paci S, Salvatici E, Zuvadelli J, Banderali G. Low bone mineralization in phenylketonuria may be due to undiagnosed metabolic acidosis. Mol Genet Metab Rep 2023; 36:100998. [PMID: 37600232 PMCID: PMC10432846 DOI: 10.1016/j.ymgmr.2023.100998] [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] [Received: 03/07/2023] [Revised: 08/04/2023] [Accepted: 08/04/2023] [Indexed: 08/22/2023] Open
Abstract
Background Dietary intervention is to date the mainstay treatment to prevent toxic phenylalanine (Phe) accumulation in PKU patients. Despite success preventing central nervous system damage, there is increasing evidence of possible other unfavorable outcomes affecting other systems, e.g. kidney and bone; underlying mechanisms are yet to be fully elucidated. Methods This observational, cross-sectional and descriptive study investigated 20 adult with PKU evaluating biochemical parameters, BMD measurements and extrapolating data from 3-days food records and protein substitutes (PS) and special low protein foods (SLPF) composition. Results Blood gas venous analysis (VBG) indices were indicative of metabolic acidosis in 60% of PKU patients and VBG pH significantly correlated with BMD's Z-score (p-value = 0.022) even if its overall mean was in range (-1.29). Low bone mineral density for chronological age (Z-score < - 2.0) was found in 4 patients (20%). Indices of kidney function were not impaired. All used PS had a moderate excess of acidity, while SLPF were alkalizing and type/variety of consumed vegetables did not determine significant changes in acid-base equilibrium. Total intakes of potassium and magnesium were lower than expected. Discussion PKU patients seem to be at risk of metabolic acidosis, directly linked to possible low bone mineralization. This may be related to the acidic composition of PS, potentially capable of acidifying the entire diet. Reported low intakes of potassium and magnesium may be relevant to these observations. Further studies are needed to better address these topics.
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Affiliation(s)
- Valentina Rovelli
- Clinical Department of Pediatrics, San Paolo Hospital, ASST Santi Paolo e Carlo, University of Milan, Italy
| | - Vittoria Ercoli
- Clinical Department of Pediatrics, San Paolo Hospital, ASST Santi Paolo e Carlo, University of Milan, Italy
| | - Alice Re Dionigi
- Clinical Department of Pediatrics, San Paolo Hospital, ASST Santi Paolo e Carlo, University of Milan, Italy
| | - Sabrina Paci
- Clinical Department of Pediatrics, San Paolo Hospital, ASST Santi Paolo e Carlo, University of Milan, Italy
| | - Elisabetta Salvatici
- Clinical Department of Pediatrics, San Paolo Hospital, ASST Santi Paolo e Carlo, University of Milan, Italy
| | - Juri Zuvadelli
- Clinical Department of Pediatrics, San Paolo Hospital, ASST Santi Paolo e Carlo, University of Milan, Italy
| | - Giuseppe Banderali
- Clinical Department of Pediatrics, San Paolo Hospital, ASST Santi Paolo e Carlo, University of Milan, Italy
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Charrière S, Maillot F, Bouée S, Douillard C, Jacob C, Schneider KM, Theil J, Arnoux JB. Health status and comorbidities of adult patients with phenylketonuria (PKU) in France with a focus on early-diagnosed patients - A nationwide study of health insurance claims data. Mol Genet Metab 2023; 139:107625. [PMID: 37329624 DOI: 10.1016/j.ymgme.2023.107625] [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: 01/05/2023] [Revised: 05/30/2023] [Accepted: 05/30/2023] [Indexed: 06/19/2023]
Abstract
BACKGROUND This study aimed at evaluating the health status and healthcare consumption of ≥16-year-old patients with phenylketonuria (PKU), with a focus on early-diagnosed patients. METHODS This retrospective observational study used health insurance claims data from the French SNDS (Système National des Données de Santé) database. Patients with PKU were identified between 2006 and 2018 by ICD-10 diagnosis codes E70.0 (classic PKU) or E70.1 (other causes of hyperphenylalaninemia). They were matched to controls by age, sex, and region. Patients with early-diagnosed PKU were defined as patients born after implementation of nationwide newborn screening in France in 1972. Outcomes were analyzed for the year 2018. RESULTS Overall, 3549 patients with PKU were identified on January 1st, 2018. Of those, 3469 patients could be matched to 17,170 controls without PKU. Of these patients, 2175 were at least 16 years old and suffered significantly more than controls from specific comorbidities of interest - osteoporosis (28.7% vs 19.8%, p < 0.0001), hypertension (20.9% vs 17.0%, p < 0.0001), hypercholesterolemia (12.8% vs 8.3%, p < 0.0001), diabetes (7.8% vs 4.7%, p < 0.0001), obesity (4.2% vs 1.3%, p < 0.0001), ischemic heart diseases (4.8% vs 2.0%, p < 0.0001), and depression (10.3% vs 8.2%, p = 0.0011). Prescriptions for many medications were also more frequent in patients with PKU than controls. Among ≥16-year-old patients, 1528 were categorized as early-diagnosed. Osteoporosis (0.3% vs 0.01%, p = 0.0035), chronic renal failure (0.6% vs 0.1%, p = 0.0020), hypertension (4.0% vs 2.7%, p = 0.0063), and obesity (2.5% vs 0.8%, p < 0.0001) were significantly more prevalent in early-diagnosed adult patients compared with matched controls. In total, 28.6% of ≥16-year-old patients with PKU and 40.4% of early-diagnosed patients with PKU received dietary amino-acid supplements. Sapropterin was prescribed to 5.0% and 7.0% patients, respectively. CONCLUSION The results indicate that PKU is associated with a significantly higher comorbidity risk along with increased pharmaceutical prescriptions in adulthood. The comorbidity burden is less distinct in early-diagnosed patients but still present. Few patients are treated specifically for PKU in adulthood. Healthcare of patients with PKU should include prevention and management of comorbidities and especially target PKU-specific treatment adherence and consistent care in specialized medical centers in adulthood.
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Affiliation(s)
- 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, UMR INSERM 1253 « iBrain », Tours, France.
| | - Stéphane Bouée
- CEMKA, 43 boulevard du Maréchal Joffre, 92340, Bourg-La-Reine, France.
| | - Claire Douillard
- Service d'endocrinologie, diabétologie, métabolisme et nutrition, Centre de Référence des Maladies Héréditaires du Métabolisme, Hôpital Huriez, CHU de Lille, 59037 Lille, France.
| | | | | | - Julia Theil
- Xcenda GmbH, Lange Laube 31, 30159 Hannover, Germany.
| | - Jean-Baptiste Arnoux
- Centre de Référence des Maladies Héréditaires du Métabolisme, Hôpital Necker-Enfants Malades, APHP, 149 rue de Sèvres, 75015 Paris, France.
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Cannet C, Bayat A, Frauendienst-Egger G, Freisinger P, Spraul M, Himmelreich N, Kockaya M, Ahring K, Godejohann M, MacDonald A, Trefz F. Phenylketonuria (PKU) Urinary Metabolomic Phenotype Is Defined by Genotype and Metabolite Imbalance: Results in 51 Early Treated Patients Using Ex Vivo 1H-NMR Analysis. Molecules 2023; 28:4916. [PMID: 37446577 DOI: 10.3390/molecules28134916] [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: 04/24/2023] [Revised: 06/13/2023] [Accepted: 06/14/2023] [Indexed: 07/15/2023] Open
Abstract
Phenylketonuria (PKU) is a rare metabolic disorder caused by mutations in the phenylalanine hydroxylase gene. Depending on the severity of the genetic mutation, medical treatment, and patient dietary management, elevated phenylalanine (Phe) may occur in blood and brain tissues. Research has recently shown that high Phe not only impacts the central nervous system, but also other organ systems (e.g., heart and microbiome). This study used ex vivo proton nuclear magnetic resonance (1H-NMR) analysis of urine samples from PKU patients (mean 14.9 ± 9.2 years, n = 51) to identify the impact of elevated blood Phe and PKU treatment on metabolic profiles. Our results found that 24 out of 98 urinary metabolites showed a significant difference (p < 0.05) for PKU patients compared to age-matched healthy controls (n = 51) based on an analysis of urinary metabolome. These altered urinary metabolites were related to Phe metabolism, dysbiosis, creatine synthesis or intake, the tricarboxylic acid (TCA) cycle, end products of nicotinamide-adenine dinucleotide degradation, and metabolites associated with a low Phe diet. There was an excellent correlation between the metabolome and genotype of PKU patients and healthy controls of 96.7% in a confusion matrix model. Metabolomic investigations may contribute to a better understanding of PKU pathophysiology.
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Affiliation(s)
| | - Allan Bayat
- Kennedy Centre, Center for PKU, 2600 Glostrup, Denmark
| | | | - Peter Freisinger
- Department of Pediatrics, School of Medicine, University of Tübingen, 72074 Tübingen, Germany
| | | | | | - Musa Kockaya
- Private Pediatric Practice, 68307 Mannheim, Germany
| | | | | | - Anita MacDonald
- Dietetic Department, Birmingham Children's Hospital, Birmingham B4 6NH, UK
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López-Mejía LA, Fernández-Lainez C, Vela-Amieva M, Ibarra-González I, Guillén-López S. The BMI Z-Score and Protein Energy Ratio in Early- and Late-Diagnosed PKU Patients from a Single Reference Center in Mexico. Nutrients 2023; 15:957. [PMID: 36839315 PMCID: PMC9960689 DOI: 10.3390/nu15040957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/26/2023] [Accepted: 02/03/2023] [Indexed: 02/17/2023] Open
Abstract
The relationship between protein and energy and their appropriate proportions in hyperphenylalaninemia (HPA) or phenylketonuria (PKU) patients in terms of growth have been poorly studied, especially in those diagnosed late. We aimed to describe the protein energy ratio (P:E) and its association with body mass index (BMI) in 638 dietetic and anthropometric assessments from 54 early- or late-diagnosed HPA/PKU patients. Dietetic and anthropometric data were analyzed and classified according to BMI Z-Score and type of diagnosis, early by newborn screening (NBS) or late. Correlation between BMI Z-Score and P:E ratio was established. Percent of dietary protein from Phe-free metabolic formula was analyzed. According to the BMI Z-Score, the majority of assessments were eutrophic (69.4%). The median P:E ratio was >4 in most of the overweight assessments. Remarkably, the underweight group consumed the highest proportion of Phe-free metabolic formula (74.5%). A positive correlation between BMI Z-Score and P:E ratio was found. The highest proportion of underweight was found in the late-diagnosed patients. Our findings might be related to their nutritional history previous to the HPA/PKU treatment. Thus, complex nutritional outcome of the late-diagnosed HPA/PKU patients deserves actions to guarantee the early diagnosis, closer nutritional follow-up and alternative therapeutic approaches.
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Affiliation(s)
- Lizbeth Alejandra López-Mejía
- Laboratorio de Errores Innatos del Metabolismo y Tamiz, Instituto Nacional de Pediatría, Secretaría de Salud, Mexico City 04530, Mexico
| | - Cynthia Fernández-Lainez
- Laboratorio de Errores Innatos del Metabolismo y Tamiz, Instituto Nacional de Pediatría, Secretaría de Salud, Mexico City 04530, Mexico
| | - Marcela Vela-Amieva
- Laboratorio de Errores Innatos del Metabolismo y Tamiz, Instituto Nacional de Pediatría, Secretaría de Salud, Mexico City 04530, Mexico
| | - Isabel Ibarra-González
- Unidad de Genética de la Nutrición, Instituto de Investigaciones Biomédicas, UNAM, Mexico City 04510, Mexico
| | - Sara Guillén-López
- Laboratorio de Errores Innatos del Metabolismo y Tamiz, Instituto Nacional de Pediatría, Secretaría de Salud, Mexico City 04530, Mexico
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Manta-Vogli PD, Dotsikas Y, Loukas YL, Schulpis KH. The phenylketonuria patient: A recent dietetic therapeutic approach. Nutr Neurosci 2020; 23:628-639. [PMID: 30359206 DOI: 10.1080/1028415x.2018.1538196] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Phenylalanine hydroxylase (PAH) deficiency, commonly named phenylketonuria (PKU) is a disorder of phenylalanine (Phe) metabolism inherited with an autosomal recessive trait. It is characterized by high blood and cerebral Phe levels, resulting in intellectual disabilities, seizures, etc. Early diagnosis and treatment of the patients prevent major neuro-cognitive deficits. Treatment consists of a lifelong restriction of Phe intake, combined with the supplementation of special medical foods, such as Amino Acid medical food (AA-mf), enriched in tyrosine (Tyr) and other amino acids and nutrients to avoid nutritional deficits. Developmental and neurocognitive outcomes for patients, however, remain suboptimal, especially when adherence to the demanding diet is poor. Additions to treatment include new, more palatable foods, based on Glycomacropeptide that contains limited amounts of Phe, the administration of large neutral amino acids to prevent phenylalanine entry into the brain and tetrahydrobiopterin cofactor capable of increasing residual PAH activity. Moreover, further efforts are underway to develop an oral therapy containing phenylalanine ammonia-lyase. Nutritional support of PKU future mothers (maternal PKU) is also discussed. This review aims to summarize the current literature on new PKU treatment strategies.
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Affiliation(s)
- Penelope D Manta-Vogli
- Department of Clinical Nutrition & Dietetics Agia Sofia Children's Hospital, Athens, Greece
| | - Yannis Dotsikas
- Department of Pharmacy, Laboratory of Pharm. Analysis, National and Kapodestrian University of Athens, Panepistimiopolis Zographou, GR 157 71, Athens, Greece
| | - Yannis L Loukas
- Department of Pharmacy, Laboratory of Pharm. Analysis, National and Kapodestrian University of Athens, Panepistimiopolis Zographou, GR 157 71, Athens, Greece
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Vardy ERLC, MacDonald A, Ford S, Hofman DL. Phenylketonuria, co-morbidity, and ageing: A review. J Inherit Metab Dis 2020; 43:167-178. [PMID: 31675115 DOI: 10.1002/jimd.12186] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 10/27/2019] [Accepted: 10/28/2019] [Indexed: 12/17/2022]
Abstract
Phenylketonuria (PKU) is a metabolic condition which, left untreated, results in severe and irreversible brain damage. Newborn screening and the development of the low phenylalanine (Phe) diet have transformed the outcomes for people with PKU. Those who have benefited from early treatment are now approaching their fifth and sixth decade. It is therefore timely to consider multi-morbidity in PKU and the effects of ageing, in parallel with the wider benefits of emerging treatment options in addition to dietary relaxation. We have conducted the first literature review of co-morbidity and ageing in the context of PKU. Avenues explored have emerged from limited study of multi-morbidity to date and the knowledge and critical enquiry of the authors. Findings suggest PKU to have a wider impact than brain development, and result in several intriguing questions that require investigation to attain the best outcomes for people with PKU in adulthood moving through to older age. We recognise the difficulty in studying longitudinal outcomes in rare diseases and emphasise the necessity to develop PKU registries and cohorts that facilitate well-designed studies to answer some of the questions raised in this review. Whilst awaiting new information in these areas we propose that clinicians engage with patients to make personalised and well-informed decisions around Phe control and assessment for co-morbidity.
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Affiliation(s)
- Emma R L C Vardy
- Department of Ageing and Complex Medicine, Salford Royal NHS Foundation Trust, Salford Care Organisation, Part of Northern Care Alliance NHS Group, Salford, UK
| | - Anita MacDonald
- Department of dietetics, Birmingham Women's and Children's NHS Trust, Birmingham, UK
| | - Suzanne Ford
- National Society for Phenylketonuria, Preston, UK
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Rabah F, Al-Thihli K, El-Naggari M, Elnour IB. A child with phenylketonuria and focal segmental glomerulosclerosis, the bright side of proteinuria. Metab Brain Dis 2017; 32:1119-1121. [PMID: 28386663 DOI: 10.1007/s11011-017-9998-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2016] [Accepted: 03/20/2017] [Indexed: 01/25/2023]
Abstract
Phenylketonuria (PKU) is the most common inborn error of amino acid metabolism. Phenylalanine hydroxylase is the underlying deficient enzyme. If left untreated, growth failure, microcephaly, global developmental delay, seizures and severe intellectual impairment would characterize the clinical picture of PKU. On the other side of protein homeostasis lies nephrotic syndrome. It is a well-known quantitative defect due to significant proteinuria. Focal segmental glomerulosclerosis (FSGS) is a special congenital variant affecting children and adults. Hereby, we describe a three- year old male child who presented with generalized edema and global developmental delay. Investigations revealed PKU along with FSGS. We assume that congenital nephrosis ameliorated the picture of PKU, and had a salutary effect on the growth and development. Such coexistence between PKU and FSGS hasn't been described before.
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Affiliation(s)
- Fatma Rabah
- Child Health Department, Sultan Qaboos University Hospital, PO Box 38, Al-Khoud 123, Muscat, Oman.
| | - Khalid Al-Thihli
- Genetics Department, Genetic and Developmental Medicine Clinic, Sultan Qaboos University Hospital, Muscat, Oman
| | - Mohamed El-Naggari
- Child Health Department, Sultan Qaboos University Hospital, PO Box 38, Al-Khoud 123, Muscat, Oman
| | - Ibtisam B Elnour
- Child Health Department, Sultan Qaboos University Hospital, PO Box 38, Al-Khoud 123, Muscat, Oman
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Abstract
PURPOSE OF REVIEW The purpose is to discuss advances in the nutritional and pharmacological management of phenylketonuria (PKU). RECENT FINDINGS Glycomacropeptide (GMP), a whey protein produced during cheese production, is a low-phenylalanine (phe) intact protein that represents a new dietary alternative to synthetic amino acids for people with PKU. Skeletal fragility is a long-term complication of PKU that based on murine research, appears to result from both genetic and nutritional factors. Skeletal fragility in murine PKU is attenuated with the GMP diet, compared with an amino acid diet, allowing greater radial bone growth. Pharmacologic therapy with tetrahydrobiopterin, acting as a molecular chaperone for phenylalanine hydroxylase, increases tolerance to dietary phe in some individuals. Large neutral amino acids inhibit phe transport across the intestinal mucosa and blood-brain barrier, and are most effective for individuals unable to comply with the low-phe diet. SUMMARY Although a low-phe synthetic amino acid diet remains the mainstay of PKU management, new nutritional and pharmacological treatment options offer alternative approaches to maintain lifelong low phe concentrations. GMP medical foods provide an alternative to amino acid formula that may improve bone health, and tetrahydrobiopterin permits some individuals with PKU to increase tolerance to dietary phe. Further research is needed to characterize the long-term efficacy of these new approaches for PKU management.
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Affiliation(s)
- Denise M. Ney
- Department of Nutritional Sciences and Waisman Center, University of Wisconsin-Madison, Milwaukee
| | - Robert D. Blank
- Department of Medicine, Division of Endocrinology, Diabetes, and Clinical Nutrition, Medical College of Wisconsin, Milwaukee
| | - Karen E. Hansen
- Department of Medicine, Division of Rheumatology, School of Medicine and Public Health, University of Wisconsin, USA
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Hennermann JB, Querfeld U. Unknown pathomechanisms of renal impairment in PKU. J Inherit Metab Dis 2013; 36:1087-8. [PMID: 24043382 DOI: 10.1007/s10545-013-9652-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Revised: 08/15/2013] [Accepted: 08/23/2013] [Indexed: 11/26/2022]
Affiliation(s)
- Julia B Hennermann
- Department of Pediatric Endocrinology, Gastroenterology and Metabolic Diseases, Charité Universitätsmedizin Berlin, Berlin, Germany,
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Vogel KR, Arning E, Wasek BL, Bottiglieri T, Gibson KM. Characterization of 2-(methylamino)alkanoic acid capacity to restrict blood-brain phenylalanine transport in Pah enu2 mice: preliminary findings. Mol Genet Metab 2013; 110 Suppl:S71-8. [PMID: 23999161 PMCID: PMC4077276 DOI: 10.1016/j.ymgme.2013.08.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Revised: 08/06/2013] [Accepted: 08/06/2013] [Indexed: 11/21/2022]
Abstract
BACKGROUND Our laboratory seeks a pharmacotherapeutic intervention for PKU that utilizes non-physiological amino acids (NPAAs) to block the accumulation of phenylalanine (Phe) in the brain. In previous studies (Vogel et al. 2013), methylation of the amino group of 2-aminoisobutyrate (AIB) provided an enhanced degree of selectivity for Phe restriction into the brain of Pah(enu2) mice in comparison to unmethylated AIB, leading to the hypothesis that 2-(methylamino)alkanoic acid analogs of AIB might represent targeted inhibitors of Phe accretion into the brain. METHODS Pah(enu2) and control mice were intraperitoneally administered (500-750 mg/kg body weight, once daily; standard 19% protein diet) AIB, methyl AIB (MAIB), isovaline, and two MAIB analogs, 2-methyl-2-(methylamino)butanoic (MeVal) and 3-methyl-2-(methylamino)pentanoic (MePent) acids for one week, followed by brain and blood isolation for amino acid analyses using UPLC. RESULTS In the brain, AIB significantly reduced Phe accretion in Pah(enu2) mice, while MeVal significantly improved glutamine and aspartic acids. Four of five test compounds improved brain threonine and arginine levels. AIB, MAIB and IsoVal significantly reduced blood Phe, with no effect of any drug intervention on other sera amino acids. CONCLUSIONS Further evaluation of AIB and the 2-(methylamino)alkanoic acids as inhibitors of brain Phe accumulation in Pah(enu2) mice is warranted, with more detailed evaluations of route of administration, combinatorial intervention, and detailed toxicity studies.
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Affiliation(s)
- Kara R. Vogel
- Section of Clinical Pharmacology, College of Pharmacy, Washington State University, Spokane, WA, USA
| | - Erland Arning
- Institute for Metabolic Disease, Baylor Research Institute and Baylor University Medical Center, Dallas, TX, USA
| | - Brandi L. Wasek
- Institute for Metabolic Disease, Baylor Research Institute and Baylor University Medical Center, Dallas, TX, USA
| | - Teodoro Bottiglieri
- Institute for Metabolic Disease, Baylor Research Institute and Baylor University Medical Center, Dallas, TX, USA
| | - K. Michael Gibson
- Section of Clinical Pharmacology, College of Pharmacy, Washington State University, Spokane, WA, USA
- Corresponding author at: Section of Clinical Pharmacology, College of Pharmacy, Washington State University, SAC 525M, P.O. Box 1495, 412 E. Spokane Falls Blvd, Spokane, WA 99210-1495, USA. Fax: +1 509 358 6673. (K.M. Gibson)
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