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Zhu T, Ye J, Han L, Qiu W, Zhang H, Liang L, Gu X. The Predictive Value of Genetic Analyses in the Diagnosis of Tetrahydrobiopterin (BH4)-Responsiveness in Chinese Phenylalanine Hydroxylase Deficiency Patients. Sci Rep 2017; 7:6762. [PMID: 28754886 PMCID: PMC5533732 DOI: 10.1038/s41598-017-06462-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 06/13/2017] [Indexed: 11/23/2022] Open
Abstract
Molecular characterization of PAH deficiency has been proven essential in establishing treatment options. We examine the diagnostic accuracy of two genetic assays to predict BH4 responsiveness: to determine whether the AV sum test or mutation-status assessment test can obviate the need for BH4 loading in Chinese patients. The overall predicted response in 346 patients was 31.65% by the AV sum test and 25.43% by the other assay; both percentages were lower than 51.06% derived from loading results in 94 patients. Responders were compound heterozygotes with definite BH4 responsive mutations, while non-responders had null/null ones; some consistently with specific mutations and genotypes. The sensitivity and specificity of the assays were 81.1% and 92.5% for the AV sum, and 82.9%, 97.3% for the other. An AV sum cutoff >2 has a positive predictive value (PPV) of 90.9%, while the presence of at least one BH4 responsive mutation has a PPV of 97.1%. The two approaches showed good concordance. Our data confirmed that the mutation-status assessment has a higher diagnostic accuracy in predicting response for Chinese patients than the AV sum test. BH4-responsiveness may be predicted or excluded from patients' molecular characteristics to some extent, thus some patients may avoid the initial loading.
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Affiliation(s)
- Tianwen Zhu
- Department of Neonatal Medicine, Xin-Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jun Ye
- Department of Endocrinology and Genetic Metabolism, Xin-Hua Hospital, Shanghai Institute of Pediatric Research Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Lianshu Han
- Department of Endocrinology and Genetic Metabolism, Xin-Hua Hospital, Shanghai Institute of Pediatric Research Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Wenjuan Qiu
- Department of Endocrinology and Genetic Metabolism, Xin-Hua Hospital, Shanghai Institute of Pediatric Research Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Huiwen Zhang
- Department of Endocrinology and Genetic Metabolism, Xin-Hua Hospital, Shanghai Institute of Pediatric Research Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Lili Liang
- Department of Endocrinology and Genetic Metabolism, Xin-Hua Hospital, Shanghai Institute of Pediatric Research Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xuefan Gu
- Department of Endocrinology and Genetic Metabolism, Xin-Hua Hospital, Shanghai Institute of Pediatric Research Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China.
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Dietary patterns, cost and compliance with low-protein diet of phenylketonuria and other inherited metabolic diseases. Eur J Clin Nutr 2017; 72:87-92. [PMID: 28656971 DOI: 10.1038/ejcn.2017.102] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 04/20/2017] [Accepted: 05/03/2017] [Indexed: 11/09/2022]
Abstract
BACKGROUND/OBJECTIVES Phenylketonuria (PKU) and several other inherited metabolic diseases (IMD) require a lifelong low-protein diet (LPD), otherwise they lead to many health complications. LPDs, however, carry a significant economic burden for patients and their families. The objective of this study was to explore the costs of low-protein foods (LPFs) necessary for LPD as well as dietary patterns and compliance towards an LPD. SUBJECTS/METHODS A detailed questionnaire was created in cooperation with National Association of PKU and other IMD (NSPKU), and consequently sent to all NSPKU members treated with an LPD (n=303). A total of 184 respondents from the Czech Republic were included in the study (174 had PKU, 10 had other IMD). RESULTS The average daily consumption of LPF was equal to 411.7 g (PKU) and 345.6 g (other IMD), which corresponds to energy value of 5558 kJ and 4438 kJ, respectively, per patient per day. Patients mostly consumed low-protein flour (≈30% of energy intake), pasta (≈18%), basic pastry (≈15%) and sweets (≈10%). The average monthly costs of LPDs were equal to [euro ]130 (PKU) and [euro ]129 (other IMD) per patient per month. The compliance with LPD was decreasing with increasing age (P<0.0001). CONCLUSIONS This is the largest study examining costs and dietary patterns of LPDs in patients with PKU and the first study of this kind in other IMD patients requiring an LPD. The study clearly showed that an LPD carries a very high economic burden for families, which may lead to less LPD compliance and potential severe health consequences.
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Rahim F, Saki Malehi A, Mohammadshahi M, Tirdad R. Combined large neutral amino acid supplementation for phenylketonuria (PKU). Hippokratia 2017. [DOI: 10.1002/14651858.cd012618] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Fakher Rahim
- Health Research Institute, Ahvaz Jundishapur University of Medical Sciences; Thalassemia & Hemoglobinopathy Research Center; Golestan Avenue Ahvaz Khuzestan Iran 61537-15794
| | - Amal Saki Malehi
- Ahvaz Jundishapur University of Medical Sciences; Department of Biostatistics and Epidemiology, School of Public Health; Golestan Ahvaz Khuzestan Iran 61537-15794
| | - Majid Mohammadshahi
- Ahvaz Jundishapur University of Medical Sciences; Department of Molecular Medicine and Molecular Epidemiology; Golestan Ahvaz Khuzestan Iran 61537-15794
| | - Roshanak Tirdad
- Ahvaz Jundishapur University of Medical Sciences; Department of Molecular Medicine and Molecular Epidemiology; Golestan Ahvaz Khuzestan Iran 61537-15794
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54
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Turki A, Ueda K, Cheng B, Giezen A, Salvarinova R, Stockler-Ipsiroglu S, Elango R. The Indicator Amino Acid Oxidation Method with the Use of l-[1-13C]Leucine Suggests a Higher than Currently Recommended Protein Requirement in Children with Phenylketonuria. J Nutr 2017; 147:211-217. [PMID: 28053173 DOI: 10.3945/jn.116.240218] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 10/01/2016] [Accepted: 12/01/2016] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Phenylketonuria is characterized by mutations in the Phe hydroxylase gene that leads to the accumulation of Phe in plasma and the brain. The standard of care for phenylketonuria is nutritional management with dietary restriction of Phe and the provision of sufficient protein and energy for growth and health maintenance. The protein requirement in children with phenylketonuria is empirically determined based upon phenylketonuria nutritional guidelines that are adjusted individually in response to biochemical markers and growth. OBJECTIVE We determined dietary protein requirements in children with phenylketonuria with the use of the indicator amino acid oxidation (IAAO) technique, with l-[1-13C]Leu as the indicator amino acid. METHODS Four children (2 males; 2 females) aged 9-18 y with phenylketonuria [mild hyperphenylalanemia (mHPA); 6-10 mg/dL (360-600 μmol/L)] were recruited to participate in ≥7 separate test protein intakes (range: 0.2-3.2 g ⋅ kg-1 ⋅ d-1) with the IAAO protocol with the use of l-[1-13C]Leu followed by the collection of breath and urine samples over 8 h. The diets were isocaloric and provided energy at 1.7 times the resting energy expenditure. Protein was provided as a crystalline amino acid mixture based on an egg protein pattern, except Phe and Leu, which were maintained at a constant across intakes. Protein requirement was determined with the use of a 2-phase linear-regression crossover analysis of the rate of l-[1-13C]Leu tracer oxidation. RESULTS The mean protein requirement was determined to be 1.85 g ⋅ kg-1 ⋅ d-1 (R2 = 0.66; 95% CI: 1.37, 2.33). This result is substantially higher than the 2014 phenylketonuria recommendations (1.14-1.33 g ⋅ kg-1 ⋅ d-1; based on 120-140% above the current RDA for age). CONCLUSIONS To our knowledge, this is the first study to directly define a quantitative requirement for protein intake in children with mHPA and indicates that current protein recommendations in children with phenylketonuria may be insufficient. This trial was registered at clinicaltrials.gov as NCT01965691.
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Affiliation(s)
- Abrar Turki
- BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada.,Department of Pediatrics and
| | - Keiko Ueda
- Department of Pediatrics and.,Division of Biochemical Diseases, BC Children's Hospital, Vancouver, British Columbia, Canada
| | - Barbara Cheng
- Department of Pediatrics and.,Division of Biochemical Diseases, BC Children's Hospital, Vancouver, British Columbia, Canada
| | - Alette Giezen
- Department of Pediatrics and.,Division of Biochemical Diseases, BC Children's Hospital, Vancouver, British Columbia, Canada
| | - Ramona Salvarinova
- Department of Pediatrics and.,Division of Biochemical Diseases, BC Children's Hospital, Vancouver, British Columbia, Canada
| | - Sylvia Stockler-Ipsiroglu
- BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada.,Department of Pediatrics and.,Division of Biochemical Diseases, BC Children's Hospital, Vancouver, British Columbia, Canada
| | - Rajavel Elango
- Department of Pediatrics and .,School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada; and.,Division of Biochemical Diseases, BC Children's Hospital, Vancouver, British Columbia, Canada
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55
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Eriksson JG, Guzzardi MA, Iozzo P, Kajantie E, Kautiainen H, Salonen MK. Higher serum phenylalanine concentration is associated with more rapid telomere shortening in men. Am J Clin Nutr 2017; 105:144-150. [PMID: 27881392 DOI: 10.3945/ajcn.116.130468] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 10/12/2016] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Telomere length and telomere shortening are associated with age-related health outcomes. Only a few studies have been able to longitudinally report on factors that are associated with changes in telomere length in an aging population. OBJECTIVE We studied the longitudinal relation between telomere length, the change in telomere length, and circulating amino acids. DESIGN A total of 812 subjects from the Helsinki Birth Cohort Study (born from 1934 to 1944), who underwent 3 clinical visits during a 10-y interval that included measurements of cardiometabolic risk factors, were included in the study. Leukocyte telomere length (LTL) was measured with the use of quantitative real-time polymerase chain reaction. Circulating branched-chain and aromatic amino acids (alanine, glycine, histidine, phenylalanine, leucine, isoleucine, valine, and tyrosine) were assessed with the use of high-throughput nuclear magnetic resonance spectroscopy. RESULTS The relative ± SD LTL at a mean age of 71 y was 0.79 ± 0.27 in men and 0.89 ± 0.35 in women (P < 0.001). Of the studied amino acids, the strongest inverse association was observed between the phenylalanine concentration that was measured 5 y earlier and the LTL. This finding was significant in men (P = 0.021) and remained significant after adjustment for multiple comparisons, but it was not significant in women (P = 0.39). Longitudinally, the change in LTL over 10 y was inversely associated with the phenylalanine concentration in men (P = 0.007) but not in women (P = 0.58) after adjustment for baseline LTL, age, smoking, and percentage of body fat. CONCLUSIONS The serum phenylalanine concentration is associated with telomere length and, therefore, potentially with the aging process. Because the associations reported are observational, no conclusions can be made regarding causality. Our findings support the hypothesis that cellular pathways that regulate aging are sex specific.
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Affiliation(s)
- Johan G Eriksson
- Department of Chronic Disease Prevention, National Institute for Health and Welfare, Helsinki, Finland; .,Department of General Practice and Primary Health Care, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.,Folkhälsan Research Center, Helsinki, Finland
| | | | - Patricia Iozzo
- Insitute of Clinical Physiology, National Research Council, Pisa, Italy
| | - Eero Kajantie
- Department of Chronic Disease Prevention, National Institute for Health and Welfare, Helsinki, Finland.,Children's Hospital, Helsinki University Hospital and University of Helsinki, Helsinki, Finland.,Department of Obstetrics and Gynecology, MRC Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland
| | - Hannu Kautiainen
- Department of General Practice and Primary Health Care, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.,Folkhälsan Research Center, Helsinki, Finland.,University of Eastern Finland, Kuopio Finland
| | - Minna K Salonen
- Department of Chronic Disease Prevention, National Institute for Health and Welfare, Helsinki, Finland.,Folkhälsan Research Center, Helsinki, Finland
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56
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Waisbren SE, Prabhu SP, Greenstein P, Petty C, Schomer D, Anastasoaie V, Charette K, Rodriguez D, Merugumala S, Lin AP. Improved Measurement of Brain Phenylalanine and Tyrosine Related to Neuropsychological Functioning in Phenylketonuria. JIMD Rep 2016; 34:77-86. [PMID: 27677920 DOI: 10.1007/8904_2016_11] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 07/25/2016] [Accepted: 08/25/2016] [Indexed: 12/05/2022] Open
Abstract
INTRODUCTION Researchers hypothesized that in phenylketonuria (PKU) high brain phenylalanine (Phe) levels and low brain tyrosine (Tyr) levels affect neuropsychological functioning. However, traditional magnetic resonance spectroscopy (MRS) yielded uncertain results of brain Phe and could not adequately measure brain Tyr. This pilot study examined the potential of correlated spectroscopy (COSY) to quantify these biomarkers and explain variability in neuropsychological functioning. METHODS Nine adults with early treated classic PKU received magnetic resonance imaging (MRI) with COSY and a battery of neuropsychological tests. Brain Phe and Tyr in parietal white matter (PWM) were compared to results in gray matter of the posterior cingulate gyrus (PCG). RESULTS Brain Phe ranged from 101 to 182 (mean = 136.76 ± 23.77) μmol/L in PCG and 76 to 185 (mean = 130.11 ± 37.88) μmol/L in PWM. Brain Tyr ranged from 4.0 to 7.4 (mean = 5.44 ± 1.01) μmol/L in PCG and 4.1 to 8.4 (mean = 5.90 ± 1.48) μmol/L in PWM. Correlation coefficients were largest for brain Phe PWM and measures of auditory memory (rho = -0.79), anxiety (rho = 0.79), and executive functioning (rho = 0.69). Associations were in the expected direction, with higher brain Phe and lower brain Tyr related to poorer functioning. The two participants with severe structural MRI abnormalities had low brain Tyr levels in PCG and 3/5 of the participants with moderate to severe MRI abnormalities had higher than average brain Phe levels. CONCLUSION COSY has the potential to quantify brain Phe and Tyr at low concentrations and in specific brain regions. In this pilot study, these biomarkers were associated with indices of neuropsychological functioning. Additional studies are needed to validate the COSY results.
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Affiliation(s)
- Susan E Waisbren
- Boston Children's Hospital, 1 Autumn Street, #525, Boston, MA, 02115, USA. .,Harvard Medical School, Boston, MA, USA.
| | - Sanjay P Prabhu
- Boston Children's Hospital, 1 Autumn Street, #525, Boston, MA, 02115, USA
| | - Patricia Greenstein
- Harvard Medical School, Boston, MA, USA.,Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Carter Petty
- Boston Children's Hospital, 1 Autumn Street, #525, Boston, MA, 02115, USA
| | - Donald Schomer
- Harvard Medical School, Boston, MA, USA.,Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Vera Anastasoaie
- Boston Children's Hospital, 1 Autumn Street, #525, Boston, MA, 02115, USA
| | - Kalin Charette
- Boston Children's Hospital, 1 Autumn Street, #525, Boston, MA, 02115, USA
| | | | | | - Alexander P Lin
- Harvard Medical School, Boston, MA, USA.,Brigham and Women's Hospital, Boston, MA, USA
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57
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Wyrwich KW, Shaffer S, Gries K, Auguste P, Mooney KH, Prasad S, Bilder DA. Content Validity of the ADHD Rating Scale (ADHD RS-IV) and Adult ADHD Self-Report Scale (ASRS) in Phenylketonuria. JOURNAL OF INBORN ERRORS OF METABOLISM AND SCREENING 2016. [DOI: 10.1177/2326409816639316] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
| | | | | | | | | | | | - Deborah A. Bilder
- Department of Psychiatry, University of Utah, Salt Lake City, UT, USA
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58
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Rohde C, Thiele AG, Och U, Schönherr K, Meyer U, Rosenbaum-Fabian S, Maddalon C, Matzken S, Blessing H, Lang F, Jörg-Streller M, Beblo S. Effect of dietary regime on metabolic control in phenylketonuria: Is exact calculation of phenylalanine intake really necessary? Mol Genet Metab Rep 2015. [PMID: 28649540 PMCID: PMC5471407 DOI: 10.1016/j.ymgmr.2015.09.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Background A phenylalanine (Phe) restricted dietary management is required in phenylketonuria (PKU) to maintain good metabolic control. Nevertheless, five different models of dietary regimes, which differ in their accuracy of Phe documentation, are used. To investigate the effect of the dietary regime on metabolic control, a multicenter evaluation was performed. Patients/Methods 149 patients (max. 800 mg Phe-intake/day; 108 children aged 1–9 years and 41 adolescents aged 10–15 years) could be included. They were separated according to age and dietary regime, revealed by a questionnaire on dietary habits. Dietary regimes vary from daily strict calculation of all Phe-intake (group 1) to a rather loose regime only estimating Phe-intake and including high protein food (group 5). Data were analyzed with respect to metabolic control (Phe-concentrations, Phe-concentrations above upper recommended limit during 6 months before the interview), Phe-intake (mg/day) and age (years). Results Median Phe-concentrations in children did not differ significantly among diet groups (group 1: 161; 2: 229, 3: 236, 4: 249, 5: 288 μmol/l, p = 0.175). However, exact daily Phe calculation led to significantly lower percentage of Phe concentrations above the upper recommended limit (group 1: 17, 2: 50, 3: 42, 4: 50, 5: 75%, p = 0.035). All included patients showed good to acceptable metabolic control. Patients on the dietary regime with the least accuracy, consuming also high protein foods, showed the poorest metabolic control. Median Phe concentrations of all other groups remained within recommended ranges, including from groups not calculating special low protein foods, fruit and vegetables and using a simplified system of recording Phe-intake. In adolescents no significant differences among diet groups were revealed. Conclusion Exact calculation of Phe content of all food is not necessary to achieve good metabolic control in children and adolescents with PKU. Excluding special low protein food, as well as fruit and vegetables from calculation of Phe-intake has no impact on metabolic control. However including protein rich food into the diet and simply estimating all Phe-intake appears insufficient. The simplification of dietary regime may be helpful in enhancing acceptability and feasibility.
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Affiliation(s)
- Carmen Rohde
- Hospital for Children and Adolescents, Department of Women and Child Health, University Hospitals, University of Leipzig, Liebigstraße 20 a, 04103 Leipzig, Germany
| | - Alena Gerlinde Thiele
- Hospital for Children and Adolescents, Department of Women and Child Health, University Hospitals, University of Leipzig, Liebigstraße 20 a, 04103 Leipzig, Germany
| | - Ulrike Och
- Muenster University Children's Hospital, Albert-Schweitzer-Campus 1, 48149 Münster, Germany
| | - Katrin Schönherr
- University Children's Hospital, Department of Clinical Genetics, Centre of treatment of metabolic diseases, Kochstr. 2, 07745 Jena, Germany
| | - Uta Meyer
- Medical School Hannover, Clinic of Pediatrics, Carl-Neuberg-Straße 1, 30625 Hannover, Germany
| | - Stefanie Rosenbaum-Fabian
- Center of Pediatrics and Adolescent Medicine, University Hospital, Department of Pediatrics, Hugstetter Straße 55, 79106 Freiburg, Germany
| | - Cornelia Maddalon
- University Children's Hospital, Steinwiesstrasse 75, 8032 Zürich, Switzerland
| | - Sabine Matzken
- Justus Liebig University, Department for General Pediatrics, Metabolic Unit, Rudolf-Buchheim-Straße, 35392 Giessen, Germany
| | - Holger Blessing
- Department for Inborn Metabolic Diseases, Children's and Adolescents' Hospital, University of Erlangen-Nürnberg, Loschgestraße 15, 91054 Erlangen, Germany
| | - Frauke Lang
- Departement of Pediatric and Adolscent Medicine, Villa Metabolica, University Medical Center, Johannes Gutenberg-University of Mainz, Langenbeckstr. 1, 55131 Mainz, Germany
| | - Monika Jörg-Streller
- Clinic for Pediatrics I, Inherited Metabolic Disorders, Medical University Innsbruck, Anichstrasse 35, 6020 Innsbruck, Austria
| | - Skadi Beblo
- Hospital for Children and Adolescents, Department of Women and Child Health, University Hospitals, University of Leipzig, Liebigstraße 20 a, 04103 Leipzig, Germany
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Thiele AG, Rohde C, Mütze U, Arelin M, Ceglarek U, Thiery J, Baerwald C, Kiess W, Beblo S. The challenge of long-term tetrahydrobiopterin (BH4) therapy in phenylketonuria: Effects on metabolic control, nutritional habits and nutrient supply. Mol Genet Metab Rep 2015; 4:62-7. [PMID: 26937412 PMCID: PMC4750587 DOI: 10.1016/j.ymgmr.2015.07.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 07/13/2015] [Accepted: 07/13/2015] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND AND AIMS BH4-sensitive phenylketonuria (PKU) patients relax their phenylalanine (Phe) restricted diet due to increased Phe tolerance, while keeping dried blood Phe concentrations with in the therapeutic range. We aimed to investigate metabolic control, eating habits and nutrient supply under long-term BH4-therapy. PATIENTS AND METHODS Retrospective analysis of mean dried blood Phe concentrations and their variability, food and nutrient intake in BH4-sensitive patients (n = 8, 3f, age 6.0-16.6 y) under classical dietary treatment for one year and during the three years after initiation of BH4. RESULTS Phe concentrations of BH4-sensitve PKU patients remained within therapeutic range throughout the observation period, independent of therapeutic regime. Under BH4, Phe tolerance increased significantly (493.2 ± 161.8 mg/d under classical diet vs 2021.93 ± 897.4 mg/d two years under BH4; P = 0.004). Variability of Phe concentrations remained unchanged (mean SD; P = 1.000). Patients adjust their food choice and significantly increased their intake of cereals, potatoes, dairy products and meat (P = 0.019, P = 0.016, P = 0.016 and P = 0.016, respectively). Under diet changes after implementation of BH4 a drop in micronutrient intake (vitamin D, folic acid, iron, calcium, iodine) could be revealed (P = 0.005, P < 0.001, P = 0.004, P = 0.001, P = 0.003, respectively). CONCLUSIONS BH4-sensitive PKU patients can achieve good metabolic control under an adjuvant BH4- or a BH4 monotherapy. The liberalized diet under BH4 seems to jeopardize the quality of patients' nutrition, and these patients require close follow-up and special nutrition education to minimize the risk for imbalanced diet and nutrient deficiencies.
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Affiliation(s)
- Alena G. Thiele
- Hospital for Children and Adolescents, Centre for Pediatric Research Leipzig (CPL), Department of Women and Child Health, University Hospitals, University of Leipzig, Liebigstraße 20 a, 04103 Leipzig, Germany
| | - Carmen Rohde
- Hospital for Children and Adolescents, Centre for Pediatric Research Leipzig (CPL), Department of Women and Child Health, University Hospitals, University of Leipzig, Liebigstraße 20 a, 04103 Leipzig, Germany
| | - Ulrike Mütze
- Hospital for Children and Adolescents, Centre for Pediatric Research Leipzig (CPL), Department of Women and Child Health, University Hospitals, University of Leipzig, Liebigstraße 20 a, 04103 Leipzig, Germany
| | - Maria Arelin
- Hospital for Children and Adolescents, Centre for Pediatric Research Leipzig (CPL), Department of Women and Child Health, University Hospitals, University of Leipzig, Liebigstraße 20 a, 04103 Leipzig, Germany
| | - Uta Ceglarek
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University of Leipzig, Liebigstraße 27, 04103 Leipzig, Germany
| | - Joachim Thiery
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University of Leipzig, Liebigstraße 27, 04103 Leipzig, Germany
| | - Christoph Baerwald
- Department of Internal Medicine, University Hospitals, University of Leipzig, Liebigstraße 20, 04103 Leipzig, Germany
| | - Wieland Kiess
- Hospital for Children and Adolescents, Centre for Pediatric Research Leipzig (CPL), Department of Women and Child Health, University Hospitals, University of Leipzig, Liebigstraße 20 a, 04103 Leipzig, Germany
| | - Skadi Beblo
- Hospital for Children and Adolescents, Centre for Pediatric Research Leipzig (CPL), Department of Women and Child Health, University Hospitals, University of Leipzig, Liebigstraße 20 a, 04103 Leipzig, Germany
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60
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Danecka MK, Woidy M, Zschocke J, Feillet F, Muntau AC, Gersting SW. Mapping the functional landscape of frequent phenylalanine hydroxylase (PAH) genotypes promotes personalised medicine in phenylketonuria. J Med Genet 2015; 52:175-85. [PMID: 25596310 DOI: 10.1136/jmedgenet-2014-102621] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
BACKGROUND In phenylketonuria, genetic heterogeneity, frequent compound heterozygosity, and the lack of functional data for phenylalanine hydroxylase genotypes hamper reliable phenotype prediction and individualised treatment. METHODS A literature search revealed 690 different phenylalanine hydroxylase genotypes in 3066 phenylketonuria patients from Europe and the Middle East. We determined phenylalanine hydroxylase function of 30 frequent homozygous and compound heterozygous genotypes covering 55% of the study population, generated activity landscapes, and assessed the phenylalanine hydroxylase working range in the metabolic (phenylalanine) and therapeutic (tetrahydrobiopterin) space. RESULTS Shared patterns in genotype-specific functional landscapes were linked to biochemical and pharmacological phenotypes, where (1) residual activity below 3.5% was associated with classical phenylketonuria unresponsive to pharmacological treatment; (2) lack of defined peak activity induced loss of response to tetrahydrobiopterin; (3) a higher cofactor need was linked to inconsistent clinical phenotypes and low rates of tetrahydrobiopterin response; and (4) residual activity above 5%, a defined peak of activity, and a normal cofactor need were associated with pharmacologically treatable mild phenotypes. In addition, we provide a web application for retrieving country-specific information on genotypes and genotype-specific phenylalanine hydroxylase function that warrants continuous extension, updates, and research on demand. CONCLUSIONS The combination of genotype-specific functional analyses with biochemical, clinical, and therapeutic data of individual patients may serve as a powerful tool to enable phenotype prediction and to establish personalised medicine strategies for dietary regimens and pharmacological treatment in phenylketonuria.
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Affiliation(s)
- Marta K Danecka
- Department of Molecular Pediatrics, Dr. von Hauner Children's Hospital, Ludwig-Maximilians-University, Munich, Germany
| | - Mathias Woidy
- Department of Molecular Pediatrics, Dr. von Hauner Children's Hospital, Ludwig-Maximilians-University, Munich, Germany
| | - Johannes Zschocke
- Division of Human Genetics, Medical University Innsbruck, Innsbruck, Austria
| | - François Feillet
- Department of Pediatrics, Hôpital d'Enfants Brabois, CHU Nancy, Vandoeuvre les Nancy, France
| | - Ania C Muntau
- University Children's Hospital, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Søren W Gersting
- Department of Molecular Pediatrics, Dr. von Hauner Children's Hospital, Ludwig-Maximilians-University, Munich, Germany
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61
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The mechanisms of neurotoxicity and the selective vulnerability of nervous system sites. HANDBOOK OF CLINICAL NEUROLOGY 2015; 131:61-70. [PMID: 26563783 DOI: 10.1016/b978-0-444-62627-1.00005-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
The spatial heterogeneity of the structure, function, and cellular composition of the nervous system confers extraordinary complexity and a multiplicity of mechanisms of chemical neurotoxicity. Because of its relatively high metabolic demands and functional dependence on postmitotic neurons, the nervous system is vulnerable to a variety of xenobiotics that affect essential homeostatic mechanisms that support function. Despite protection from the neuroglia and blood-brain barrier, the central nervous system is prone to attack from lipophilic toxicants and those that hijack endogenous transport, receptor, metabolic, and other biochemical systems. The inherent predilection of chemicals for highly conserved biochemical systems confers selective vulnerability of the nervous system to neurotoxicants. This chapter discusses selective vulnerability of the nervous system in the context of neuron-specific decrements (axonopathy, myelinopathy, disruption of neurotransmission), and the degree to which neuronal damage is facilitated or ameliorated by surrounding nonneural cells in both the central and peripheral nervous systems.
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Hood A, Grange DK, Christ SE, Steiner R, White DA. Variability in phenylalanine control predicts IQ and executive abilities in children with phenylketonuria. Mol Genet Metab 2014; 111:445-51. [PMID: 24568837 PMCID: PMC4144445 DOI: 10.1016/j.ymgme.2014.01.012] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 01/24/2014] [Accepted: 01/24/2014] [Indexed: 10/25/2022]
Abstract
A number of studies have revealed significant relationships between cognitive performance and average phenylalanine (Phe) levels in children with phenylketonuria (PKU), but only a few studies have been conducted to examine the relationships between cognitive performance and variability (fluctuations) in Phe levels. In the current study, we examined a variety of indices of Phe control to determine which index best predicted IQ and executive abilities in 47 school-age children with early- and continuously-treated PKU. Indices of Phe control were mean Phe, the index of dietary control, change in Phe with age, and several indices of variability in Phe (standard deviation, standard error of estimate, and percentage of spikes). These indices were computed over the lifetime and during 3 developmental epochs (<5, 5.0-9.9, and ≥10 years of age). Results indicated that variability in Phe was generally a stronger predictor of cognitive performance than other indices of Phe control. In addition, executive performance was better predicted by variability in Phe during older than younger developmental epochs. These results indicate that variability in Phe should be carefully controlled to maximize cognitive outcomes and that Phe control should not be liberalized as children with PKU age.
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Affiliation(s)
- Anna Hood
- Department of Psychology, Campus Box 1125, Washington University, St. Louis, MO 63130, USA
| | - Dorothy K Grange
- Department of Pediatrics, Campus Box 8116, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Shawn E Christ
- Department of Psychological Sciences, 210 McAlester Hall, University of Missouri, Columbia, MO 65211, USA
| | - Robert Steiner
- Department of Pediatrics, Institute on Development and Disability, 3181 SW Sam Jackson Park Rd., Oregon Health & Science University, Portland, OR 97239, USA; Department of Molecular & Medical Genetics, Institute on Development and Disability, 3181 SW Sam Jackson Park Rd., Oregon Health & Science University, Portland, OR 97239, USA
| | - Desirée A White
- Department of Psychology, Campus Box 1125, Washington University, St. Louis, MO 63130, USA.
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