1
|
Pardo J, Capdevila-Lacasa C, Segura B, Pané A, Montserrat C, de Talló Forga-Visa M, Moreno PJ, Garrabou G, Grau-Junyent JM, Junqué C. Volumetric brain reductions in adult patients with phenylketonuria and their relationship with blood phenylalanine levels. J Neurodev Disord 2024; 16:33. [PMID: 38907189 PMCID: PMC11193301 DOI: 10.1186/s11689-024-09553-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Accepted: 06/17/2024] [Indexed: 06/23/2024] Open
Abstract
BACKGROUND Continued dietary treatment since early diagnosis through newborn screening programs usually prevents brain-related complications in phenylketonuria (PKU). However, subtle neurocognitive and brain alterations may be observed in some adult patients despite early treatment. Nevertheless, neuropsychological and neuroimaging studies in the field remain scarce. OBJECTIVES This work aimed to determine possible neuropsychological and structural brain alterations in treated adult patients with PKU. METHODS Thirty-five patients with PKU and 22 healthy controls (HC) underwent neuropsychological assessment and T1-weighted magnetic resonance imaging on a 3 T scanner. FreeSurfer (v.7.1) was used to obtain volumetric measures and SPSS (v27.0.1.0) was used to analyze sociodemographic, neuropsychological, volumetric, and clinical data (p < 0.05). RESULTS Adult patients with PKU showed significantly lower performance than HC in Full Scale IQ (t = 2.67; p = .010) from the WAIS-IV. The PKU group also showed significantly lower volumes than HC in the pallidum (U = 224.000; p = .008), hippocampus (U = 243.000; p = .020), amygdala (U = 200.000; p = .002), and brainstem (t = 3.17; p = .006) as well as in total cerebral white matter volume (U = 175.000; p = .001). Blood phenylalanine (Phe) levels in PKU patients were negatively correlated with the pallidum (r = -0.417; p = .013) and brainstem (r = -0.455, p = .006) volumes. CONCLUSIONS Adult patients with early-treated PKU showed significantly lower global intelligence than HC. Moreover, these patients showed reduced global white matter volume as well as reductions in the volume of several subcortical grey matter structures, which might be related to the existence of underlying neurodevelopmental alterations. Higher blood Phe levels were also negatively correlated with pallidum and brainstem, suggesting a higher vulnerability of these structures to Phe toxicity.
Collapse
Affiliation(s)
- Jèssica Pardo
- Institute of Neurosciences, Medical Psychology Unit, Department of Medicine, University of Barcelona, C/ Casanova 143, Barcelona, Catalonia, 08036, Spain
- Fundació de Recerca Clínic Barcelona-Institut d'Investigacions Biomèdiques August Pi I Sunyer (FRCB-IDIBAPS), Barcelona, Catalonia, Spain
| | - Clara Capdevila-Lacasa
- Institute of Neurosciences, Medical Psychology Unit, Department of Medicine, University of Barcelona, C/ Casanova 143, Barcelona, Catalonia, 08036, Spain
- Fundació de Recerca Clínic Barcelona-Institut d'Investigacions Biomèdiques August Pi I Sunyer (FRCB-IDIBAPS), Barcelona, Catalonia, Spain
| | - Bàrbara Segura
- Institute of Neurosciences, Medical Psychology Unit, Department of Medicine, University of Barcelona, C/ Casanova 143, Barcelona, Catalonia, 08036, Spain.
- Fundació de Recerca Clínic Barcelona-Institut d'Investigacions Biomèdiques August Pi I Sunyer (FRCB-IDIBAPS), Barcelona, Catalonia, Spain.
- Biomedical Research Networking Center On Neurodegenerative Diseases (CIBERNED: CB06/05/0018-ISCIII), Barcelona, Catalonia, Spain.
| | - Adriana Pané
- Biomedical Research Networking Center on Physiopathology of Obesity and Nutrition (CIBEROBN), Barcelona, Catalonia, Spain
- Endocrinology and Nutrition Department, Adult Inherited Metabolic Disorders Unit (UECMA), Hospital Clínic de Barcelona, Barcelona, Catalonia, Spain
| | - Cristina Montserrat
- Endocrinology and Nutrition Department, Adult Inherited Metabolic Disorders Unit (UECMA), Hospital Clínic de Barcelona, Barcelona, Catalonia, Spain
| | - Maria de Talló Forga-Visa
- Endocrinology and Nutrition Department, Adult Inherited Metabolic Disorders Unit (UECMA), Hospital Clínic de Barcelona, Barcelona, Catalonia, Spain
| | - Pedro J Moreno
- Internal Medicine Department, Adult Inherited Metabolic Disorders Unit (UECMA), Hospital Clínic de Barcelona, Barcelona, Catalonia, Spain
- Inherited Metabolic Diseases and Muscle Disorders Research, Centre de Recerca Biomèdica CELLEX - Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) and Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Catalonia, Spain
- Biomedical Research Networking Center on Rare Diseases (CIBERER), Barcelona, Catalonia, Spain
| | - Glòria Garrabou
- Internal Medicine Department, Adult Inherited Metabolic Disorders Unit (UECMA), Hospital Clínic de Barcelona, Barcelona, Catalonia, Spain
- Inherited Metabolic Diseases and Muscle Disorders Research, Centre de Recerca Biomèdica CELLEX - Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) and Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Catalonia, Spain
- Biomedical Research Networking Center on Rare Diseases (CIBERER), Barcelona, Catalonia, Spain
| | - Josep M Grau-Junyent
- Internal Medicine Department, Adult Inherited Metabolic Disorders Unit (UECMA), Hospital Clínic de Barcelona, Barcelona, Catalonia, Spain
- Inherited Metabolic Diseases and Muscle Disorders Research, Centre de Recerca Biomèdica CELLEX - Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) and Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Catalonia, Spain
- Biomedical Research Networking Center on Rare Diseases (CIBERER), Barcelona, Catalonia, Spain
| | - Carme Junqué
- Institute of Neurosciences, Medical Psychology Unit, Department of Medicine, University of Barcelona, C/ Casanova 143, Barcelona, Catalonia, 08036, Spain
- Fundació de Recerca Clínic Barcelona-Institut d'Investigacions Biomèdiques August Pi I Sunyer (FRCB-IDIBAPS), Barcelona, Catalonia, Spain
- Biomedical Research Networking Center On Neurodegenerative Diseases (CIBERNED: CB06/05/0018-ISCIII), Barcelona, Catalonia, Spain
| |
Collapse
|
2
|
Esgi M, Ergun H, Kaya NY, Atakay DY, Erucar E, Celik F. Phenylketonuria from the perspectives of patients in Türkiye. Orphanet J Rare Dis 2024; 19:78. [PMID: 38378595 PMCID: PMC10880278 DOI: 10.1186/s13023-024-03079-z] [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: 03/21/2023] [Accepted: 02/03/2024] [Indexed: 02/22/2024] Open
Abstract
BACKGROUND The present study aimed to determine the problems, unmet needs and expectations of phenylketonuria (PKU) patients in Türkiye regarding follow-up and treatment in order to provide data for future planning and implementations on PKU. METHODS The study included patients diagnosed with PKU and/or their parents. They were informed about the study via phone calls and their verbal consents were obtained. Questions in the data collection forms, which were established separately for pediatric, adolescent, and adult age groups, were applied during the interviews and the answers were recorded. RESULTS Among 182 classical PKU patients, 66 (36.3%) were in the pediatric group (0-12 years old), 44 (24.2%) were in the adolescent group (13-19 years old), and 72 (39.5%) were in the adult group (≥ 20 years old). In all patient groups, phenylalanine-restricted diet and medical nutrition products were the main options for treatment. The median of the last measured blood phenylalanine concentration (patient-reported) was 290 µmol/L, 425 µmol/L, and 750 µmol/L in the pediatric, adolescent, and adult groups, respectively. The frequency of blood testing for serum phenylalanine level according to the age groups was appropriate in nearly half of the patients. While the majority of the patients have been visiting the metabolism center they have been diagnosed with PKU for control, considerable proportion of the patients would like to change the center or the doctor they visit for control if they could. It was determined that nearly half of the patients had trouble in accessing the metabolism center. Treatment options' being limited and expensive were the major problems. The main requests of the patients and patient relatives included easier access to the metabolism centers and more options for treatment and diet. CONCLUSIONS Access to the services should be easier to improve the patients' follow-up and treatment. There is need for low-cost, easily applicable, and accessible nutrition products and effective novel pharmacological agents. Focusing on these issues in health policies by providing pedagogic/psychological support, establishing support programs also comprising the families, and increasing the awareness activities were the key outcomes.
Collapse
Affiliation(s)
- Merve Esgi
- Department of Nutrition and Dietetics, Faculty of Health Sciences, Kocaeli University, Kocaeli, Türkiye.
| | - Hakan Ergun
- Department of Medical Pharmacology, Ankara University Faculty of Medicine, Ankara, Türkiye
| | | | | | - Ege Erucar
- Faculty of Medicine, Altinbas University, Istanbul, Türkiye
| | - Fatma Celik
- Food and Drug Department, Parma University, Parma, Italy
| |
Collapse
|
3
|
Pinto A, Daly A, Rocha JC, Ashmore C, Evans S, Ilgaz F, Hickson M, MacDonald A. Natural Protein Intake in Children with Phenylketonuria: Prescription vs. Actual Intakes. Nutrients 2023; 15:4903. [PMID: 38068761 PMCID: PMC10708375 DOI: 10.3390/nu15234903] [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: 10/26/2023] [Revised: 11/16/2023] [Accepted: 11/19/2023] [Indexed: 12/18/2023] Open
Abstract
In phenylketonuria (PKU), an important component of the UK dietary management system is a 50 mg phenylalanine (Phe)/1 g protein exchange system used to allocate the Phe/natural protein intakes according to individual patient tolerance. Any foods containing protein ≤ 0.5 g/100 g or fruits/vegetables containing Phe ≤ 75 mg/100 g are allowed without measurement or limit. In children with PKU, we aimed to assess the difference between the prescribed natural protein intake and their actual consumed intake, and to calculate the natural protein/Phe intake from foods given without measurement or restriction. Over a 6-month duration, three one-day diet diaries were collected every month by caregivers of children with PKU at the beginning of a follow-up study. Dietary intakes of Phe, as well as natural and total protein intakes, were calculated using Nutritics® (v5.09). Weekly blood Phe spots were collected by caregivers. The target blood Phe level was ≤360 μmol/L for ages up to 12 years and ≤600 μmol/L for ages ≥12 years. Sixteen early treated children (69% females) with PKU were recruited. The median age was 11 years (range: 9-13), and most had classical PKU (n = 14/16). A median of 18 (range 12-18) one-day diaries and 22 blood spots were analysed for each subject over 6 months. The median prescribed natural protein was 6 g/day (range: 3-27), but when calculated, the actual median intake from all foods consumed was 10 g/day (range: 4-37). The median prescribed Phe was 300 mg/day (range: 150-1350), but the actual median intake was 500 mg/day (range: 200-1850). The median difference between the prescribed and actual natural protein daily intakes was +4 g/day (range: -2.5 to +11.5), with a median percentage increase of 40% for natural protein/Phe intake (p < 0.001). The median blood Phe level was 250 μmol/L (range 20-750), with 91% of blood Phe levels within the target range. Only one patient (11 years) had less than 75% of their blood Phe levels within the target range. The UK Phe exchange system provides flexibility in the dietary management of PKU. With this method, the actual natural protein intake was 167% higher than the prescribed amount. Although this led to a variable daily protein intake, the majority of children (n = 15/16) experienced no deterioration in their metabolic control.
Collapse
Affiliation(s)
- Alex Pinto
- Birmingham Women’s and Children’s Hospital, Birmingham B4 6NH, UK; (A.D.); (C.A.); (S.E.); (F.I.); (A.M.)
- Plymouth Institute of Health and Care Research, Faculty of Health, University of Plymouth, Plymouth PL6 8BH, UK;
| | - Anne Daly
- Birmingham Women’s and Children’s Hospital, Birmingham B4 6NH, UK; (A.D.); (C.A.); (S.E.); (F.I.); (A.M.)
| | - Júlio César Rocha
- Nutrition and Metabolism, NOVA Medical School (NMS), Faculdade de Ciências Médicas (FCM), Universidade Nova de Lisboa, 1169-056 Lisboa, Portugal;
- CINTESIS@RISE, Nutrition and Metabolism, NOVA Medical School (NMS), Faculdade de Ciências Médicas, (FCM), Universidade NOVA de Lisboa, 1169-056 Lisboa, Portugal
- Reference Centre of Inherited Metabolic Diseases, Centro Hospitalar Universitario de Lisboa Central, 1169-045 Lisboa, Portugal
| | - Catherine Ashmore
- Birmingham Women’s and Children’s Hospital, Birmingham B4 6NH, UK; (A.D.); (C.A.); (S.E.); (F.I.); (A.M.)
| | - Sharon Evans
- Birmingham Women’s and Children’s Hospital, Birmingham B4 6NH, UK; (A.D.); (C.A.); (S.E.); (F.I.); (A.M.)
| | - Fatma Ilgaz
- Birmingham Women’s and Children’s Hospital, Birmingham B4 6NH, UK; (A.D.); (C.A.); (S.E.); (F.I.); (A.M.)
- Department of Nutrition and Dietetics, Faculty of Health Sciences, Hacettepe University, 06100 Ankara, Turkey
| | - Mary Hickson
- Plymouth Institute of Health and Care Research, Faculty of Health, University of Plymouth, Plymouth PL6 8BH, UK;
| | - Anita MacDonald
- Birmingham Women’s and Children’s Hospital, Birmingham B4 6NH, UK; (A.D.); (C.A.); (S.E.); (F.I.); (A.M.)
- Plymouth Institute of Health and Care Research, Faculty of Health, University of Plymouth, Plymouth PL6 8BH, UK;
| |
Collapse
|
4
|
De Giorgi A, Nardecchia F, Romani C, Leuzzi V. Metabolic control and clinical outcome in adolescents with phenylketonuria. Mol Genet Metab 2023; 140:107684. [PMID: 37672857 DOI: 10.1016/j.ymgme.2023.107684] [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: 06/30/2023] [Revised: 08/11/2023] [Accepted: 08/11/2023] [Indexed: 09/08/2023]
Abstract
The main neurological, cognitive, and behavioural consequences of phenylketonuria have been eradicated thanks to new-born screening and Phe-restricted diet therapy. However, the effects of high phenylalanine levels during adolescence and adulthood on neurocognitive functions remain a concern. This systematic review aimed at collecting clinical data suggesting the safest metabolic target for early treated PKU during the second decade of life. Twenty studies met the inclusion criteria for full-text review. Relevant studies included papers that (a) examined the relationship between metabolic control and neurocognitive functions during adolescence or (b) investigated the impact of metabolic control in adolescence on adult outcomes. Most studies showed a positive correlation between metabolic control during adolescence and neurocognitive outcomes across ages. This was true both for IQ and executive functions, although data on executive functions were less clear, and it remains to be established whether they are more vulnerable to Phe than IQ. Taken together present evidence confirm brain vulnerability to Phe during adolescence and suggests that low average Phe levels and low Phe fluctuations should be maintained throughout life. While results are fully compatible with current European recommendations, clinical and methodological limitations coupled with remarkable interindividual variability prevented a clear identification of a safe threshold for Phe blood levels during adolescence.
Collapse
Affiliation(s)
- Agnese De Giorgi
- Unit of Child Neurology and Psychiatry, Department of Human Neuroscience, Sapienza University of Rome, Rome, Italy
| | - Francesca Nardecchia
- Unit of Child Neurology and Psychiatry, Department of Human Neuroscience, Sapienza University of Rome, Rome, Italy
| | - Cristina Romani
- School of Life and Health Sciences, Aston University, Birmingham, UK
| | - Vincenzo Leuzzi
- Unit of Child Neurology and Psychiatry, Department of Human Neuroscience, Sapienza University of Rome, Rome, Italy.
| |
Collapse
|
5
|
De Giorgi A, Nardecchia F, Manti F, Campistol J, Leuzzi V. Neuroimaging in early-treated phenylketonuria patients and clinical outcome: A systematic review. Mol Genet Metab 2023; 139:107588. [PMID: 37149991 DOI: 10.1016/j.ymgme.2023.107588] [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: 02/16/2023] [Revised: 04/20/2023] [Accepted: 04/21/2023] [Indexed: 05/09/2023]
Abstract
Lacking direct neuropathological data, neuroimaging exploration has become the most powerful tool to give insight into pathophysiological alterations of early-treated PKU (ETPKU) patients. We conducted a systematic review of neuroimaging studies in ETPKU patients to explore 1) the occurrence of consistent neuroimaging alterations; 2) the relationship between them and neurological and cognitive disorders; 3) the contribution of neuroimaging in the insight of neuropathological background of ETPKU subjects; 4) whether brain neuroimaging may provide additional information in the monitoring of the disease course. Thirty-eight studies met the inclusion criteria for the full-text review, including morphological T1/T2 sequences, diffusion brain imaging (DWI/DTI) studies, brain MRI volumetric, functional neuroimaging studies, neurotransmission and brain energetic imaging studies. Non-progressive brain white matter changes were the most frequent and precocious alterations. As confirmed in hundreds of young adults with ETPKU, they affect over 90% of ETPKU patients. Consistent correlations are emerging between microstructural alteration (as detected by DWI/DTI) and metabolic control, which have also been confirmed in a few interventional trials. Volumetric studies detected later and less consistent cortical and subcortical grey matter alterations, which seem to be influenced by the patient's age and metabolic control. The few functional neuroimaging studies so far showed preliminary but interesting data about cortical activation patterns, skill performance, and brain connectivity. Further research is mandatory in these more complex areas. Recurrent methodological limitations include restricted sample sizes concerning the clinical variability of the disease, large age-range, variable measures of metabolic control, and prevalence of cross-sectional rather than longitudinal interventional studies.
Collapse
Affiliation(s)
- Agnese De Giorgi
- Division of Child Neurology and Infantile Psychiatry, Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
| | - Francesca Nardecchia
- Division of Child Neurology and Infantile Psychiatry, Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
| | - Filippo Manti
- Division of Child Neurology and Infantile Psychiatry, Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
| | - Jaume Campistol
- Neuropaediatrics Department, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Spain
| | - Vincenzo Leuzzi
- Division of Child Neurology and Infantile Psychiatry, Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy.
| |
Collapse
|
6
|
Krämer J, Baerwald C, Heimbold C, Kamrath C, Parhofer KG, Reichert A, Rutsch F, Stolz S, Weinhold N, Muntau AC. Two years of pegvaliase in Germany:Experiences and best practice recommendations. Mol Genet Metab 2023; 139:107564. [PMID: 37086569 DOI: 10.1016/j.ymgme.2023.107564] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/31/2023] [Accepted: 03/31/2023] [Indexed: 04/04/2023]
Abstract
BACKGROUND In 2019, pegvaliase was approved in Europe for the treatment of phenylketonuria (PKU) in patients aged 16 years and older with blood phenylalanine (Phe) concentrations above 600 μmol/L despite prior management with available treatment options. Since its European approval, German metabolic centres have gained valuable experience, which may be of benefit to other treatment centres managing patients on pegvaliase. METHODS After a virtual meeting that was attended by nine German physicians, three German dietitians and one American physician, a follow-up discussion was held via an online platform to develop a set of recommendations on the use of pegvaliase in Germany. Eight German physicians contributed to the follow-up discussion and subsequent consensus voting, using a modified Delphi technique. The recommendations were supported by literature and retrospectively collected patient data. RESULTS Consensus (≥75% agreement) was achieved on 25 recommendations, covering seven topics deemed relevant by the expert panel when considering pegvaliase an option for the treatment of patients with PKU. In addition to the recommendations, a retrospective chart review was conducted in seven of the centres and included 71 patients who initiated treatment with pegvaliase. Twenty-seven patients had been treated for at least 24 months and 23 (85.2%) had achieved blood Phe ≤600 μmol/L with some degree of diet normalisation. Of these patients, 14 had physiological blood Phe on a normalised diet. CONCLUSION The practical consensus recommendations provide guidance on the different steps along the pegvaliase journey from clinical site requirements to treatment goals and outcomes. The recommendations are intended to support less experienced European metabolic centres with the implementation of pegvaliase, emphasising that a core treatment team consisting of at least a dietitian and metabolic physician is sufficient to initiate pegvaliase and support patients during their treatment journey.
Collapse
|
7
|
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).
Collapse
|
8
|
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: 8] [Impact Index Per Article: 4.0] [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.
Collapse
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.
| | | | | |
Collapse
|
9
|
Lotz-Havla AS, Katzdobler S, Nuscher B, Weiß K, Levin J, Havla J, Maier EM. Serum glial fibrillary acidic protein and neurofilament light chain in patients with early treated phenylketonuria. Front Neurol 2022; 13:1011470. [PMID: 36247773 PMCID: PMC9559705 DOI: 10.3389/fneur.2022.1011470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 09/12/2022] [Indexed: 12/01/2022] Open
Abstract
To pave the way for healthy aging in early treated phenylketonuria (ETPKU) patients, a better understanding of the neurological course in this population is needed, requiring easy accessible biomarkers to monitor neurological disease progression in large cohorts. The objective of this pilot study was to investigate the potential of glial fibrillary acidic protein (GFAP) and neurofilament light chain (NfL) as blood biomarkers to indicate changes of the central nervous system in ETPKU. In this single-center cross-sectional study, GFAP and NfL concentrations in serum were quantified using the Simoa® multiplex technology in 56 ETPKU patients aged 6–36 years and 16 age matched healthy controls. Correlation analysis and hierarchical linear regression analysis were performed to investigate an association with disease-related biochemical parameters and retinal layers assessed by optical coherence tomography. ETPKU patients did not show significantly higher GFAP concentrations (mean 73 pg/ml) compared to healthy controls (mean 60 pg/ml, p = 0.140). However, individual pediatric and adult ETPKU patients had GFAP concentrations above the healthy control range. In addition, there was a significant association of GFAP concentrations with current plasma tyrosine concentrations (r = −0.482, p = 0.036), a biochemical marker in phenylketonuria, and the retinal inner nuclear layer volume (r = 0.451, p = 0.04). There was no evidence of NfL alterations in our ETPKU cohort. These pilot results encourage multicenter longitudinal studies to further investigate serum GFAP as a complementary tool to better understand and monitor neurological disease progression in ETPKU. Follow-up investigations on aging ETPKU patients are required to elucidate the potential of serum NfL as biomarker.
Collapse
Affiliation(s)
- Amelie S. Lotz-Havla
- Department of Pediatrics, Dr. von Hauner Children's Hospital, University Hospital, LMU Munich, Munich, Germany
| | - Sabrina Katzdobler
- Department of Neurology, University Hospital, LMU Munich, Munich, Germany
| | - Brigitte Nuscher
- Department of Neurology, University Hospital, LMU Munich, Munich, Germany
| | - Katharina Weiß
- Department of Pediatrics, Dr. von Hauner Children's Hospital, University Hospital, LMU Munich, Munich, Germany
| | - Johannes Levin
- Department of Neurology, University Hospital, LMU Munich, Munich, Germany
- German Center for Neurodegenerative Diseases, site Munich, Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Joachim Havla
- Institute of Clinical Neuroimmunology, University Hospital, LMU Munich, Munich, Germany
- Data Integration for Future Medicine (DIFUTURE) Consortium, LMU Munich, Munich, Germany
- *Correspondence: Joachim Havla
| | - Esther M. Maier
- Department of Pediatrics, Dr. von Hauner Children's Hospital, University Hospital, LMU Munich, Munich, Germany
- Esther M. Maier
| |
Collapse
|
10
|
A comprehensive assessment of neurocognitive and psychological functioning in adults with early-treated phenylketonuria. J Int Neuropsychol Soc 2022:1-10. [PMID: 36134437 DOI: 10.1017/s1355617722000686] [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] [Indexed: 11/07/2022]
Abstract
OBJECTIVE Relative to youth with early-treated phenylketonuria (ETPKU), much less is known regarding the cognitive profile of adults with ETPKU. The present study aimed to address this gap by providing a comprehensive assessment of neuropsychological functioning among adults with ETPKU. METHOD A sample of 40 adults with ETPKU (ages 18 - 36) and a demographically matched group of 32 healthy individuals without PKU participated. Participants completed a comprehensive neuropsychological battery including the NIH Toolbox, Wechsler Abbreviated Scale of Intelligence - Second Edition (WASI-II), Conners' Continuous Performance Test (CPT-3), select subtests from the Weschler Adult Intelligence Scale - Fourth Edition (WAIS-IV) as well as several self-report measures of cognitive and psychoemotional functioning. Scores from these tests were combined to create cognitive composites reflecting overall task performance in the areas of verbal ability, visuospatial skills, executive functioning, motor skills, and processing speed. RESULTS No group differences were observed for full scale IQ or verbal ability. However, individuals with ETPKU demonstrated poorer performance on measures of executive functioning, processing speed, motor skills, and visuospatial skills as compared to the non-PKU group. Within the ETPKU group, recent blood phenylalanine levels (an indicator of metabolic control) were significantly correlated with performance across most cognitive domains and aspects of psychological functioning. CONCLUSIONS Present findings suggest that the neuropsychological profile of adult ETPKU is characterized by circumscribed impairments in select cognitive domains. In addition, the results underscore the importance of maintaining metabolic control across the lifespan in individuals with ETPKU.
Collapse
|
11
|
Burton BK, Hermida Á, Bélanger-Quintana A, Bell H, Bjoraker KJ, Christ SE, Grant ML, Harding CO, Huijbregts SCJ, Longo N, McNutt MC, Nguyen-Driver MD, Santos Pessoa AL, Rocha JC, Sacharow S, Sanchez-Valle A, Sivri HS, Vockley J, Walterfang M, Whittle S, Muntau AC. Management of early treated adolescents and young adults with phenylketonuria: Development of international consensus recommendations using a modified Delphi approach. Mol Genet Metab 2022; 137:114-126. [PMID: 36027720 DOI: 10.1016/j.ymgme.2022.07.012] [Citation(s) in RCA: 6] [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: 04/25/2022] [Revised: 06/16/2022] [Accepted: 07/23/2022] [Indexed: 11/20/2022]
Abstract
BACKGROUND Early treated patients with phenylketonuria (PKU) often become lost to follow-up from adolescence onwards due to the historical focus of PKU care on the pediatric population and lack of programs facilitating the transition to adulthood. As a result, evidence on the management of adolescents and young adults with PKU is limited. METHODS Two meetings were held with a multidisciplinary international panel of 25 experts in PKU and comorbidities frequently experienced by patients with PKU. Based on the outcomes of the first meeting, a set of statements were developed. During the second meeting, these statements were voted on for consensus generation (≥70% agreement), using a modified Delphi approach. RESULTS A total of 37 consensus recommendations were developed across five areas that were deemed important in the management of adolescents and young adults with PKU: (1) general physical health, (2) mental health and neurocognitive functioning, (3) blood Phe target range, (4) PKU-specific challenges, and (5) transition to adult care. The consensus recommendations reflect the personal opinions and experiences from the participating experts supported with evidence when available. Overall, clinicians managing adolescents and young adults with PKU should be aware of the wide variety of PKU-associated comorbidities, initiating screening at an early age. In addition, management of adolescents/young adults should be a joint effort between the patient, clinical center, and parents/caregivers supporting adolescents with gradually gaining independent control of their disease during the transition to adulthood. CONCLUSIONS A multidisciplinary international group of experts used a modified Delphi approach to develop a set of consensus recommendations with the aim of providing guidance and offering tools to clinics to aid with supporting adolescents and young adults with PKU.
Collapse
Affiliation(s)
- Barbara K Burton
- Ann and Robert H. Lurie Children's Hospital and Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
| | - Álvaro Hermida
- Clinical University Hospital of Santiago de Compostela, University of Santiago de Compostela, CIBERER, MetabERN, Institute of Clinical Research of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | | | - Heather Bell
- Fred A. Litwin Family Centre in Genetic Medicine, University Health Network and Mount Sinai Hospital, Toronto, ON, Canada
| | | | - Shawn E Christ
- Department of Psychological Sciences, University of Missouri, Columbia, MO, USA
| | - Mitzie L Grant
- Department of Psychiatry, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Cary O Harding
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, OR, USA
| | | | - Nicola Longo
- Division of Medical Genetics, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Markey C McNutt
- McDermott Center for Human Growth and Development, UT Southwestern Medical Center, Dallas, TX, USA
| | - Mina D Nguyen-Driver
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, OR, USA
| | - André L Santos Pessoa
- Pediatric Neurology Service, Albert Sabin Children's Hospital, University of Ceará State, Fortaleza, Ceará, Brazil
| | - Júlio César Rocha
- Nutrition and Metabolism, NOVA Medical School, Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Portugal; Neuropsychiatry Unit, Royal Melbourne Hospital, Melbourne, VIC, Australia; Melbourne Neuropsychiatry Centre, University of Melbourne, Melbourne, VIC, Australia
| | - Stephanie Sacharow
- CINTESIS-Center for Health Technology and Services Research, NOVA Medical School, Lisboa, Portugal; Florey Institute of Neuroscience and Mental Health, Melbourne, VIC, Australia
| | - Amarilis Sanchez-Valle
- Reference Centre of Inherited Metabolic Diseases, Centro Hospitalar Universitário de Lisboa Central, Lisboa, Portugal
| | - H Serap Sivri
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA
| | - Jerry Vockley
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Mark Walterfang
- Department of Pediatrics, Morsani College of Medicine, University of South Florida, Tampa, FL, USA; Melbourne Neuropsychiatry Centre, Department of Psychiatry, University of Melbourne, Melbourne, VIC, Australia; University Children's Hospital, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Sarah Whittle
- Hacettepe University, Faculty of Medicine, Department of Pediatrics, Section of Pediatric Metabolism, Ankara, Turkey
| | - Ania C Muntau
- Department of Pediatrics, University of Pittsburgh Medical Center Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| |
Collapse
|
12
|
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.
Collapse
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.
| |
Collapse
|
13
|
Dobrowolski SF, Phua YL, Sudano C, Spridik K, Zinn PO, Wang Y, Bharathi S, Vockley J, Goetzman E. Comparative metabolomics in the Pah enu2 classical PKU mouse identifies cerebral energy pathway disruption and oxidative stress. Mol Genet Metab 2022; 136:38-45. [PMID: 35367142 PMCID: PMC9759961 DOI: 10.1016/j.ymgme.2022.03.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 03/08/2022] [Indexed: 01/06/2023]
Abstract
Classical phenylketonuria (PKU, OMIM 261600) owes to hepatic deficiency of phenylalanine hydroxylase (PAH) that enzymatically converts phenylalanine (Phe) to tyrosine (Tyr). PKU neurologic phenotypes include impaired brain development, decreased myelination, early onset mental retardation, seizures, and late-onset features (neuropsychiatric, Parkinsonism). Phe over-representation is systemic; however, tissue response to hyperphenylalaninemia is not consistent. To characterize hyperphenylalaninemia tissue response, metabolomics was applied to Pahenu2 classical PKU mouse blood, liver, and brain. In blood and liver over-represented analytes were principally Phe, Phe catabolites, and Phe-related analytes (Phe-conjugates, Phe-containing dipeptides). In addition to Phe and Phe-related analytes, the metabolomic profile of Pahenu2 brain tissue evidenced oxidative stress responses and energy dysregulation. Glutathione and homocarnosine anti-oxidative responses are apparent Pahenu2 brain. Oxidative stress in Pahenu2 brain was further evidenced by increased reactive oxygen species. Pahenu2 brain presents an increased NADH/NAD ratio suggesting respiratory chain complex 1 dysfunction. Respirometry in Pahenu2 brain mitochondria functionally confirmed reduced respiratory chain activity with an attenuated response to pyruvate substrate. Glycolysis pathway analytes are over-represented in Pahenu2 brain tissue. PKU pathologies owe to liver metabolic deficiency; yet, Pahenu2 liver tissue shows neither energy disruption nor anti-oxidative response. Unique aspects of metabolomic homeostasis in PKU brain tissue along with increased reactive oxygen species and respiratory chain deficit provide insight to neurologic disease mechanisms. While some elements of assumed, long standing PKU neuropathology are enforced by metabolomic data (e.g. reduced tryptophan and serotonin representation), energy dysregulation and tissue oxidative stress expand mechanisms underlying neuropathology.
Collapse
Affiliation(s)
- Steven F Dobrowolski
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15224, United States of America.
| | - Yu Leng Phua
- Division of Medical Genetics, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15224, United States of America
| | - Cayla Sudano
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15224, United States of America
| | - Kayla Spridik
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15224, United States of America
| | - Pascal O Zinn
- Department of Neurological Surgery, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15224, United States of America
| | - Yudong Wang
- Division of Medical Genetics, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15224, United States of America
| | - Sivakama Bharathi
- Division of Medical Genetics, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15224, United States of America
| | - Jerry Vockley
- Division of Medical Genetics, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15224, United States of America
| | - Eric Goetzman
- Division of Medical Genetics, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15224, United States of America
| |
Collapse
|
14
|
Cicek C, Eren-Koçak E, Telkoparan-Akillilar P, Gok M, Bodur E. cAMP/PKA-CREB-BDNF signaling pathway in hippocampus of rats subjected to chemically-induced phenylketonuria. Metab Brain Dis 2022; 37:545-557. [PMID: 34800207 DOI: 10.1007/s11011-021-00865-7] [Citation(s) in RCA: 5] [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: 02/26/2021] [Accepted: 10/31/2021] [Indexed: 12/13/2022]
Abstract
Phenylketonuria (PKU) is an inborn error disease in phenylalanine metabolism resulting from defects in the stages of converting phenylalanine to tyrosine. Although the pathophysiology of PKU is not elucidated yet, the toxic effect of phenylalanine on the brain causes severe mental retardation. In relation to learning and memory, the hippocampal PKA / CREB / BDNF pathway may play a role in learning deficits in PKU patients. This study aimed to investigate PKA/CREB/BDNF pathway in hippocampus of chemically induced PKU rats with regard to gender. Sprague-Dawley rat pups were randomized into two groups of both genders. To chemically induce PKU, animals received subcutaneous administration of phenylalanine (5.2 mmol / g) plus p-chlorophenylalanine, phenylalanine hydroxylase inhibitor (0.9 mmol / g); control animals received 0.9% NaCl. Injections started on the 6th day and continued until the 21st day after which locomotor activity, learning and memory were tested. In male PKU rats, locomotor activity was reduced. There were no differences in learning and memory performances of male and female PKU rats. In PKU rats, pCREB / CREB levels in males was unchanged while it decreased in females. Elevated PKA activity, BDNF levels and decreased pCREB/CREB ratio found in female PKU rats were not replicated in PKU males in which BDNF is decreased. Our results display that in this disease model a gender specific differential activation of cAMP/PKA-CREB-BDNF signaling pathway in hippocampus occurs investigation of which can help us to a better understanding of disease pathophysiology.
Collapse
Affiliation(s)
- Cigdem Cicek
- Department of Medical Biochemistry, Hacettepe University, Faculty of Medicine, 06100, Ankara, Turkey
- Department of Medical Biochemistry, Yuksek Ihtisas University, Faculty of Medicine, 06520, Ankara, Turkey
| | - Emine Eren-Koçak
- Hacettepe University, Institute of Neurological Sciences and Psychiatry, 06100, Ankara, Turkey
| | | | - Muslum Gok
- Department of Medical Biochemistry, Hacettepe University, Faculty of Medicine, 06100, Ankara, Turkey
- Department of Medical Biochemistry, Mugla Sitki Kocman University, Faculty of Medicine, 48000, Mugla, Turkey
| | - Ebru Bodur
- Department of Medical Biochemistry, Hacettepe University, Faculty of Medicine, 06100, Ankara, Turkey.
| |
Collapse
|
15
|
Lotz-Havla AS, Weiß K, Schiergens K, Regenauer-Vandewiele S, Parhofer KG, Christmann T, Böhm L, Havla J, Maier EM. Optical Coherence Tomography to Assess Neurodegeneration in Phenylalanine Hydroxylase Deficiency. Front Neurol 2021; 12:780624. [PMID: 34956063 PMCID: PMC8703042 DOI: 10.3389/fneur.2021.780624] [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: 09/21/2021] [Accepted: 11/02/2021] [Indexed: 11/13/2022] Open
Abstract
In phenylalanine hydroxylase (PAH) deficiency, an easily feasible method to access the progression of neurodegeneration is warranted to contribute to current discussions on treatment indications and targets. The objective of the present study was to investigate whether optical coherence tomography (OCT) measures as markers of neurodegeneration differ between patients with PAH deficiency and healthy controls (HCs) according to phenotype and metabolic control. In this single-center cross-sectional study, 92 patients with different phenotypes of PAH deficiency [PAH deficiency not requiring treatment, early treated phenylketonuria (ETPKU), and late-diagnosed phenylketonuria (PKU)] compared with 76 HCs were examined using spectral-domain OCT. Indices of phenylalanine elevation and variability were correlated with OCT parameters. Late-diagnosed PKU patients showed reduced peripapillary retinal nerve fiber layer (pRNFL) thickness and combined ganglion cell and inner plexiform layer (GCIPL) volume. Adult ETPKU patients were found to have lower GCIPL volume (p = 0.016), which correlated with the indices of phenylalanine control. In pediatric ETPKU patients with poor metabolic control, pRNFL was significantly reduced (p = 0.004). Patients with PAH deficiency not requiring treatment did not exhibit retinal degeneration. Inner nuclear layer (INL) was significantly increased in the pediatric ETPKU patients, driven by those with current poor metabolic control (p = 0.006). Our data provide evidence of retinal neuroaxonal degeneration and INL swelling, depending on the phenotype, current age, and metabolic control. These findings suggest that OCT is suitable to investigate neurodegeneration in PKU and we propose OCT as a sensitive, reliable, safe, low-burden, and low-cost examination for future multicenter studies.
Collapse
Affiliation(s)
- Amelie S Lotz-Havla
- Dr. von Hauner Children's Hospital, LMU University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Katharina Weiß
- Dr. von Hauner Children's Hospital, LMU University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Katharina Schiergens
- Dr. von Hauner Children's Hospital, LMU University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany
| | | | - Klaus G Parhofer
- Medical Department IV - Grosshadern, LMU University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Tara Christmann
- Institute of Clinical Neuroimmunology, LMU University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Luise Böhm
- Institute of Clinical Neuroimmunology, LMU University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Joachim Havla
- Institute of Clinical Neuroimmunology, LMU University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany.,Data Integration for Future Medicine (DIFUTURE) Consortium, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Esther M Maier
- Dr. von Hauner Children's Hospital, LMU University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany
| |
Collapse
|
16
|
Hong S, Zhu T, Zheng S, Zhan X, Xu F, Gu X, Liang L. Gene expression profiles in the brain of phenylketonuria mouse model reversed by the low phenylalanine diet therapy. Metab Brain Dis 2021; 36:2405-2414. [PMID: 34524592 DOI: 10.1007/s11011-021-00818-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 08/04/2021] [Indexed: 11/29/2022]
Abstract
To gain insight into the potential protective mechanisms of low phenylalanine diet (LPD) in phenylketonuria (PKU), gene expression profiles were studied in the cerebral cortex and hippocampus of a PKU mouse model (BTBR-Pahenu2). PKU mice were fed with low Phe diet (LPD-PKU group) and normal diet (PKU group). Wild-type mice were treated with normal diet (WT group) as control. After 12 weeks, we detected gene expression in the cerebral cortex and hippocampus of the three groups by RNA-sequencing, and then screened the differentially-expressed genes (DEGs) among the groups by bioinformatics analyses. We found that the transcriptional profiles of both cerebral cortex and hippocampus changed markedly between PKU and WT mice. Furthermore, LPD changed the transcriptional profiles of the cerebral cortex and the hippocampus of PKU mice significantly, especially in the cerebral cortex, with overlaps of genes that changed with the disease and altered by LPD treatment. In the cerebral cortex, hundreds of DEGs enriched in a wide spectrum of biological processes, molecular function, and cellular component, including nervous system development, axon development and guidance, calcium ion binding, modulation of chemical synaptic transmission, and regulation of protein kinase activity. In the hippocampus, the overlapping genes were enriched in positive regulation of long term synaptic, negative regulation of excitatory postsynaptic potential, positive regulation of synapse assembly. Our results showed that genes impaired in PKU and then rescued by LPD might indicate the potential protective capability of LPD in the PKU brain.
Collapse
Affiliation(s)
- Sha Hong
- Department of Neonatal Medicine, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Tianwen Zhu
- Department of Neonatal Medicine, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Simin Zheng
- Department of Neonatal Medicine, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xia Zhan
- Department of Pediatric Endocrinology and Genetic Metabolism, Shanghai Institute for Pediatric Research, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Kongjiang Road 1665#, Shanghai, 200092, China
| | - Feng Xu
- Department of Pediatric Endocrinology and Genetic Metabolism, Shanghai Institute for Pediatric Research, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Kongjiang Road 1665#, Shanghai, 200092, China
| | - Xuefan Gu
- Department of Pediatric Endocrinology and Genetic Metabolism, Shanghai Institute for Pediatric Research, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Kongjiang Road 1665#, Shanghai, 200092, China.
| | - Lili Liang
- Department of Pediatric Endocrinology and Genetic Metabolism, Shanghai Institute for Pediatric Research, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Kongjiang Road 1665#, Shanghai, 200092, China.
| |
Collapse
|
17
|
Scala I, Concolino D, Nastasi A, Esposito G, Crisci D, Sestito S, Ferraro S, Albano L, Ruoppolo M, Parenti G, Strisciuglio P. Beneficial Effects of Slow-Release Large Neutral Amino Acids after a Phenylalanine Oral Load in Patients with Phenylketonuria. Nutrients 2021; 13:nu13114012. [PMID: 34836270 PMCID: PMC8618154 DOI: 10.3390/nu13114012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 10/29/2021] [Accepted: 11/05/2021] [Indexed: 11/16/2022] Open
Abstract
The mainstay of phenylketonuria treatment is a low protein diet, supplemented with phenylalanine (Phe)-free protein substitutes and micronutrients. Adhering to this diet is challenging, and even patients with good metabolic control who follow the dietary prescriptions in everyday life ignore the recommendations occasionally. The present study explores the ability of slow-release large neutral amino acids (srLNAAs) to prevent Phe increase following a Phe dietary load. Fourteen phenylketonuric patients aged ≥13 years were enrolled in a 6-week protocol. Oral acute Phe loads of 250 and 500 mg were added to the evening meal together with srLNAAs (0.5 gr/kg). Phe and tyrosine were dosed before dinner, 2h-after dinner, and after the overnight fast. After oral Phe loads, mean plasma Phe remained stable and below 600 µmol/L. No Phe peaks were registered. Tyrosine levels significantly increased, and Phe/Tyrosine ratio decreased. No adverse events were registered. In conclusion, a single oral administration of srLNAAs at the dose of 0.5 gr/kg is effective in maintaining stable plasma Phe during acute oral loads with Phe-containing food and may be added to the dietetic scheme in situations in which patients with generally good adherence to diet foresee a higher than prescribed Phe intake due to their commitments.
Collapse
Affiliation(s)
- Iris Scala
- Department of Maternal and Child Health, Federico II University Hospital, 80131 Naples, Italy
- Correspondence: ; Tel.: +39-081-7463348; +39-081-7463769
| | - Daniela Concolino
- Pediatric Unit, Department of Health Sciences, Magna Graecia University of Catanzaro, 88100 Catanzaro, Italy; (D.C.); (S.S.); (S.F.)
| | - Anna Nastasi
- Physiology Nutrition Unit, Department of Clinical Medicine and Surgery, Federico II University, 80131 Naples, Italy;
| | - Giulia Esposito
- Department of Translational Medical Science, Section of Pediatrics, Federico II University, 80131 Naples, Italy; (G.E.); (G.P.); (P.S.)
| | - Daniela Crisci
- CEINGE Biotecnologie Avanzate Scarl, 80131 Naples, Italy; (D.C.); (L.A.); (M.R.)
| | - Simona Sestito
- Pediatric Unit, Department of Health Sciences, Magna Graecia University of Catanzaro, 88100 Catanzaro, Italy; (D.C.); (S.S.); (S.F.)
| | - Stefania Ferraro
- Pediatric Unit, Department of Health Sciences, Magna Graecia University of Catanzaro, 88100 Catanzaro, Italy; (D.C.); (S.S.); (S.F.)
| | - Lucia Albano
- CEINGE Biotecnologie Avanzate Scarl, 80131 Naples, Italy; (D.C.); (L.A.); (M.R.)
| | - Margherita Ruoppolo
- CEINGE Biotecnologie Avanzate Scarl, 80131 Naples, Italy; (D.C.); (L.A.); (M.R.)
- Department of Molecular Medicine and Medical Biotechnologies, Federico II University, 80131 Naples, Italy
| | - Giancarlo Parenti
- Department of Translational Medical Science, Section of Pediatrics, Federico II University, 80131 Naples, Italy; (G.E.); (G.P.); (P.S.)
- Telethon Institute of Genetics and Medicine, 80078 Pozzuoli, Italy
| | - Pietro Strisciuglio
- Department of Translational Medical Science, Section of Pediatrics, Federico II University, 80131 Naples, Italy; (G.E.); (G.P.); (P.S.)
| |
Collapse
|
18
|
McGinnity CJ, Riaño Barros DA, Guedj E, Girard N, Symeon C, Walker H, Barrington SF, Summers M, Pitkanen M, Rahman Y. A Retrospective Case Series Analysis of the Relationship Between Phenylalanine: Tyrosine Ratio and Cerebral Glucose Metabolism in Classical Phenylketonuria and Hyperphenylalaninemia. Front Neurosci 2021; 15:664525. [PMID: 34220424 PMCID: PMC8248344 DOI: 10.3389/fnins.2021.664525] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 04/28/2021] [Indexed: 11/13/2022] Open
Abstract
We retrospectively examined the relationship between blood biomarkers, in particular the historical mean phenylalanine to tyrosine (Phe:Tyr) ratio, and cerebral glucose metabolism. We hypothesized that the historical mean Phe:Tyr ratio would be more predictive of cerebral glucose metabolism than the phenylalanine (Phe) level alone. We performed a retrospective case series analysis involving 11 adult classical phenylketonuria/hyperphenylalaninemia patients under the care of an Inherited Metabolic & Neuropsychiatry Clinic who had complained of memory problems, collating casenote data from blood biochemistry, and clinical [18F]fluorodeoxyglucose positron emission tomography ([18F]FDG PET). The Phe:Tyr ratio was calculated for individual blood samples and summarized as historical mean Phe:Tyr ratio (Phe:Tyr) and historical standard deviation in Phe:Tyr ratio (SD-Phe:Tyr), for each patient. Visual analyses of [18F]FDG PET revealed heterogeneous patterns of glucose hypometabolism for eight patients. [18F]FDG PET standardized uptake was negatively correlated with Phe in a large cluster with peak localized to right superior parietal gyrus. Even larger clusters of negative correlation that encompassed most of the brain, with frontal peaks, were observed with Phe:Tyr, and SD-Phe:Tyr. Our case series analysis provides further evidence for the association between blood biomarkers, and cerebral glucose hypometabolism. Mean historical blood Phe:Tyr ratio, and its standard deviation over time, appear to be more indicative of global cerebral glucose metabolism in patients with memory problems than Phe.
Collapse
Affiliation(s)
- Colm J McGinnity
- King's College London and Guy's and St Thomas' PET Centre, School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | | | - Eric Guedj
- APHM, CNRS, Centrale Marseille, Institut Fresnel, Timone Hospital, CERIMED, Nuclear Medicine Department, Aix-Marseille University, Marseille, France
| | - Nadine Girard
- Aix-Marseille University, APHM, CNRS, CRMBM, Marseille, France
| | - Christopher Symeon
- South London and Maudsley NHS Foundation Trust, London, United Kingdom.,Institute of Psychiatry, Psychology & Neuroscience, King's Health Partners, King's College London, London, United Kingdom
| | - Helen Walker
- South London and Maudsley NHS Foundation Trust, London, United Kingdom.,West London NHS Trust, London, United Kingdom
| | - Sally F Barrington
- King's College London and Guy's and St Thomas' PET Centre, School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Mary Summers
- South London and Maudsley NHS Foundation Trust, London, United Kingdom
| | - Mervi Pitkanen
- South London and Maudsley NHS Foundation Trust, London, United Kingdom.,Institute of Psychiatry, Psychology & Neuroscience, King's Health Partners, King's College London, London, United Kingdom
| | - Yusof Rahman
- Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
| |
Collapse
|
19
|
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.
Collapse
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
| |
Collapse
|
20
|
Long-Term Neurological Outcomes of Adult Patients with Phenylketonuria before and after Newborn Screening in Japan. Int J Neonatal Screen 2021; 7:ijns7020021. [PMID: 33919983 PMCID: PMC8167766 DOI: 10.3390/ijns7020021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 03/29/2021] [Accepted: 04/12/2021] [Indexed: 11/17/2022] Open
Abstract
Japanese newborn screening (NBS) for phenylketonuria (PKU) was initiated in 1977. We surveyed the neurological outcomes of Japanese adult patients with PKU to investigate the long-term effects and of and issues with NBS. Eighty-five patients with PKU aged over 19 years who continued to be treated with a phenylalanine-free amino acid formula were investigated by administering questionnaires regarding clinical characteristics, such as mental ability, education status, and therapeutic condition. Of the 85 subjects, 68 patients were detected by NBS (NBS group), while the other 17 were clinically diagnosed before the initiation of NBS (pre-NBS group). Further, 10 of the 68 NBS patients presented intellectual and/or psychiatric disabilities, 5 of whom had a history of treatment discontinuation; in contrast, 12 of the 17 pre-NBS patients presented with neuropsychiatric symptoms. Regarding social outcomes, almost all patients in the NBS group could live an independent life, while over half of the patients in the pre-NBS group were not employed or lived in nursing-care facilities. Neurological outcomes are obviously improved by NBS in Japan. However, some patients, even those detected by NBS, developed neuropsychiatric symptoms due to treatment disruption. Lifelong and strict management is essential to maintain good neurological and social prognoses for patients with PKU.
Collapse
|
21
|
Dobrowolski SF, Phua YL, Sudano C, Spridik K, Zinn PO, Wang Y, Bharathi S, Vockley J, Goetzman E. Phenylalanine hydroxylase deficient phenylketonuria comparative metabolomics identifies energy pathway disruption and oxidative stress. Mol Genet Metab 2021:S1096-7192(21)00686-7. [PMID: 33846068 DOI: 10.1016/j.ymgme.2021.04.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 04/02/2021] [Accepted: 04/02/2021] [Indexed: 11/15/2022]
Abstract
Classical phenylketonuria (PKU, OMIM 261600) owes to hepatic deficiency of phenylalanine hydroxylase (PAH) that enzymatically converts phenylalanine (Phe) to tyrosine (Tyr). PKU neurologic phenotypes include impaired brain development, decreased myelination, early onset mental retardation, seizures, and late-onset features (neuropsychiatric, Parkinsonism). PAH deficiency leads to systemic hyperphenylalaninemia; however, the impact of Phe varies between tissues. To characterize tissue response to hyperphenylalaninemia, metabolomics was applied to tissue from therapy noncompliant classical PKU patients (blood, liver), the Pahenu2 classical PKU mouse (blood, liver, brain) and the PAH deficient pig (blood, liver, brain, cerebrospinal fluid). In blood, liver, and CSF from both patients and animal models over-represented analytes were principally Phe, Phe catabolites, and Phe-related analytes (conjugates, Phe-containing dipeptides). In addition to Phe and Phe-related analytes, the metabolomic profile of PKU brain tissue (mouse, pig) evidenced oxidative stress responses and energy dysregulation. In Pahenu2 and PKU pig brain tissues, anti-oxidative response by glutathione and homocarnosine is apparent. Oxidative stress in Pahenu2 brain was further demonstrated by increased reactive oxygen species. In Pahenu2 and PKU pig brain, an increased NADH/NAD ratio suggests a respiratory chain dysfunction. Respirometry in PKU brain mitochondria (mouse, pig) functionally confirmed reduced respiratory chain activity. Glycolysis pathway analytes are over-represented in PKU brain tissue (mouse, pig). PKU pathologies owe to liver metabolic deficiency; yet, PKU liver tissue (mouse, pig, human) shows neither energy disruption nor anti-oxidative response. Unique aspects of metabolomic homeostasis in PKU brain tissue along with increased reactive oxygen species and respiratory chain deficit provide insight to neurologic disease mechanisms. While some elements of assumed, long standing PKU neuropathology are enforced by metabolomic data (e.g. reduced tryptophan and serotonin representation), energy dysregulation and tissue oxidative stress expand mechanisms underlying neuropathology.
Collapse
Affiliation(s)
- Steven F Dobrowolski
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15224, United States.
| | - Yu Leng Phua
- Division of Medical Genetics, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15224, United States
| | - Cayla Sudano
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15224, United States
| | - Kayla Spridik
- Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15224, United States
| | - Pascal O Zinn
- Department of Neurological Surgery, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15224, United States
| | - Yudong Wang
- Division of Medical Genetics, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15224, United States
| | - Sivakama Bharathi
- Division of Medical Genetics, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15224, United States
| | - Jerry Vockley
- Division of Medical Genetics, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15224, United States
| | - Eric Goetzman
- Division of Medical Genetics, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15224, United States
| |
Collapse
|
22
|
Burgess NM, Kelso W, Malpas CB, Winton-Brown T, Fazio T, Panetta J, De Jong G, Neath J, Atherton S, Velakoulis D, Walterfang M. The effect of improved dietary control on cognitive and psychiatric functioning in adults with phenylketonuria: the ReDAPT study. Orphanet J Rare Dis 2021; 16:35. [PMID: 33461585 PMCID: PMC7814424 DOI: 10.1186/s13023-020-01668-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 12/22/2020] [Indexed: 11/16/2022] Open
Abstract
Background Phenylketonuria (PKU) is an autosomal recessive inherited disorder characterised by a deficiency in phenylalanine hydroxylase. Untreated, PKU is associated with a wide range of cognitive and psychiatric sequelae. Contemporary management guidelines recommend lifetime dietary control of phenylalanine (Phe) levels, however many individuals who discontinue dietary control subsequently suffer symptoms of anxiety, depression and disturbances to cognition. We undertook a prospective cohort study of patients with early-treated phenylketonuria who had ceased dietary control to test the hypothesis that resumption of dietary control of PKU is associated with improvements in measures of psychiatric morbidity and cognitive functioning. Methods We re-initiated dietary control for early-treated patients with PKU and monitored cognitive and psychiatric outcomes over a twelve-month period. Assessments included objective cognitive function (measured by cognitive proficiency index (CPI)), anxiety and depression scales. General linear mixed model (GLMM) analyses were performed to assess change in psychometric variables from baseline over twelve months after resumption of dietary control. Results A total of nine patients were recruited. Mean age was 33 years (SD = 8.75), five were female. Mean time off dietary control was 19.1 years (SD = 11.3), and mean baseline phenylalanine (Phe) levels were 1108 µmol/L (SD = 293). GLMM analysis demonstrated a positive relationship between CPI and time on diet (b = 0.56 [95% CI = 0.17, 0.95]). Age, time off diet, Phe levels and depression scores were not associated with cognitive function. There was a negative relationship between time on diet and anxiety (b = − 0.88 95% CI = [− 1.26, − 0.50]) and depression ratings (b = − 0.61, 95% CI = [− 0.95, − 0.26]). Conclusions This study demonstrated improvements in cognitive function, anxiety, and depression ratings associated with resumption of dietary control of PKU. Raw Phe levels were not strongly associated with psychiatric or cognitive scores in this cohort. These findings support the importance of lifelong treatment for PKU in improving the cognitive and psychiatric sequelae of the disease.
Collapse
Affiliation(s)
- Nicholas M Burgess
- Neuropsychiatry Unit, Royal Melbourne Hospital, Level 2, John Cade Building, Melbourne,, 3050, Australia
| | - Wendy Kelso
- Neuropsychiatry Unit, Royal Melbourne Hospital, Level 2, John Cade Building, Melbourne,, 3050, Australia
| | - Charles B Malpas
- Department of Neurology, Royal Melbourne Hospital, Melbourne, Australia.,Clinical Outcomes Research Unit (CORe), Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, Melbourne, Australia.,Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Australia
| | - Toby Winton-Brown
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Australia
| | - Timothy Fazio
- Department of Metabolic Medicine, Royal Melbourne Hospital, Melbourne, Australia.,Melbourne Medical School, Department of Medicine and Radiology, University of Melbourne, Parkville, Australia
| | - Julie Panetta
- Department of Metabolic Medicine, Royal Melbourne Hospital, Melbourne, Australia
| | - Gerard De Jong
- Department of Metabolic Medicine, Royal Melbourne Hospital, Melbourne, Australia
| | - Joanna Neath
- Neuropsychiatry Unit, Royal Melbourne Hospital, Level 2, John Cade Building, Melbourne,, 3050, Australia
| | | | - Dennis Velakoulis
- Neuropsychiatry Unit, Royal Melbourne Hospital, Level 2, John Cade Building, Melbourne,, 3050, Australia.,Melbourne Neuropsychiatry Centre, University of Melbourne and North-Western Mental Health, Melbourne, Australia
| | - Mark Walterfang
- Neuropsychiatry Unit, Royal Melbourne Hospital, Level 2, John Cade Building, Melbourne,, 3050, Australia. .,Melbourne Neuropsychiatry Centre, University of Melbourne and North-Western Mental Health, Melbourne, Australia. .,Florey Institute of Neuroscience and Mental Health, Melbourne, Australia.
| |
Collapse
|
23
|
Diffusion kurtosis imaging detects subclinical white matter abnormalities in Phenylketonuria. NEUROIMAGE-CLINICAL 2021; 29:102555. [PMID: 33461111 PMCID: PMC7814191 DOI: 10.1016/j.nicl.2020.102555] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 12/02/2020] [Accepted: 12/29/2020] [Indexed: 12/19/2022]
Abstract
OBJECTIVE Phenylketonuria (PKU) is an autosomal recessive disorder whereby deficiencies in phenylalanine metabolism cause progressive neurological dysfunction. Managing PKU is challenging, with disease monitoring focussed on short-term phenylalanine control rather than measures of neuronal damage. Conventional imaging lacks sensitivity, however diffusion kurtosis imaging (DKI), a new MRI method may reveal subclinical white matter structural changes in PKU. METHODS This cohort study involved adults with PKU recruited during routine clinical care. MRI, neurocognitive assessment and historical phenylalanine (Phe) levels were collected. A hypothesis-generating case study comparing diet-compliant and non-compliant siblings confirmed that DKI metrics are sensitive to dietary adherence and prompted a candidate metric (Krad/KFA ratio). We then tested this metric in a Replication cohort (PKU = 20; controls = 43). RESULTS Both siblings scored outside the range of controls for all DKI-based metrics, with severe changes in the periventricular white matter and a gradient of severity toward the cortex. Krad/KFA provided clear separation by diagnosis in the Replication cohort (p < 0.001 in periventricular, deep and pericortical compartments). The ratio also correlated negatively with attention (r = -0.51 & -0.50, p < 0.05) and positively with 3-year mean Phe (r = 0.45 & 0.58, p < 0.01). CONCLUSION DKI reveals regionally-specific, progressive abnormalities of brain diffusion characteristics in PKU, even in the absence of conspicuous clinical signs or abnormalities on conventional MRI. A DKI-based marker derived from these scores (Krad/KFA ratio) was sensitive to cognitive impairment and PKU control over the medium term and may provide a meaningful subclinical biomarker of end-organ damage.
Collapse
|
24
|
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.
Collapse
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
| |
Collapse
|
25
|
Clocksin HE, Hawks ZW, White DA, Christ SE. Inter- and intra-tract analysis of white matter abnormalities in individuals with early-treated phenylketonuria (PKU). Mol Genet Metab 2021; 132:11-18. [PMID: 33334682 DOI: 10.1016/j.ymgme.2020.12.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 12/02/2020] [Accepted: 12/02/2020] [Indexed: 11/22/2022]
Abstract
Even with early and continuous treatment, individuals with phenylketonuria (PKU) may exhibit abnormalities of cortical white matter (WM). The present study utilizes a new analysis approach called Automated Fiber-Tract Quantification (AFQ) to advance our understanding of the tract-specific patterns of change in WM abnormalities in individuals with early-treated PKU (ETPKU). Diffusion Tensor Imaging (DTI) data from a sample of 22 individuals with ETPKU and a demographically-matched sample of 21 healthy individuals without PKU was analyzed using AFQ. In addition, a subsample of 8 individuals with ETPKU was reevaluated six months later after demonstrating a significant reduction in blood phe levels following initiation of sapropterin treatment. Within-tract AFQ analyses revealed significant location-by-group interactions for several WM tracts throughout the brain. In most cases, ETPKU-related disruptions in mean diffusivity (MD) were more apparent in posterior (as compared to anterior) aspects of a given tract. Reduction in blood phe levels with the aforementioned ETPKU subsample was associated with a similar pattern of improvement (posterior-to-anterior) within most tracts. Taken together, these findings suggest that there is a systematic pattern of change in WM abnormalities in individuals with ETPKU in a posterior-to-anterior manner along individual WM tracts.
Collapse
Affiliation(s)
- Hayley E Clocksin
- Department of Psychological Sciences, University of Missouri, Columbia, MO, 65211, USA
| | - Zoë W Hawks
- Department of Psychological and Brain Sciences, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Desirée A White
- Department of Psychological and Brain Sciences, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Shawn E Christ
- Department of Psychological Sciences, University of Missouri, Columbia, MO, 65211, USA.
| |
Collapse
|
26
|
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.
Collapse
|
27
|
Trimarco B, Manti F, Nardecchia F, Melogno S, Testa M, Meledandri G, Carducci C, Penge R, Leuzzi V. Executive functioning, adaptive skills, emotional and behavioral profile: A comparison between autism spectrum disorder and phenylketonuria. Mol Genet Metab Rep 2020; 23:100577. [PMID: 32181141 PMCID: PMC7066217 DOI: 10.1016/j.ymgmr.2020.100577] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 02/22/2020] [Indexed: 01/24/2023] Open
Abstract
INTRODUCTION Influential theories maintain that some of Autism Spectrum Disorder (ASD) core symptoms may arise from deficits in executive functions (EF). EF deficits are also considered a neuropsychological marker of early treated individuals with phenylketonuria (PKU). Aims of this study were: to verify the occurrence and patterns of specific EF impairments in both clinical groups; to explore the coexistence of EF alterations with adaptive, behavioral and emotional problems in each clinical condition. MATERIAL AND METHODS We assessed EF, adaptive, behavioral and emotional profile in 21 participants with ASD, 15 early treated PKU individuals, comparable for age and IQ, and 14 controls, comparable for age to the clinical groups (age range: 7-14 years). RESULTS ASD and PKU participants presented two different, but partially overlapping patterns of EF impairment. While ASD participants showed a specific deficit in cognitive flexibility only, PKU individuals showed a more extensive impairment in EF with a weaker performance in two core EF domains (inhibition, cognitive flexibility) as compared to healthy controls. Psychological and adaptive profile was typical in PKU participants, while ASD participants experienced behavioral (externalizing symptoms), emotional (internalizing symptoms) and adaptive disorders (general, practical, social domains). CONCLUSIONS Present results support the view of a relative disengagement of adaptive and emotional-behavioral profile with respect to EF skills and suggest that other dysfunctions contribute to the multidimensional phenotype of ASD participants.
Collapse
Affiliation(s)
- Barbara Trimarco
- Department of Human Neuroscience, “Sapienza” University of Rome, Via dei Sabelli 108, 00185 Rome, Italy
| | - Filippo Manti
- Department of Human Neuroscience, “Sapienza” University of Rome, Via dei Sabelli 108, 00185 Rome, Italy
| | - Francesca Nardecchia
- Department of Human Neuroscience, “Sapienza” University of Rome, Via dei Sabelli 108, 00185 Rome, Italy
| | - Sergio Melogno
- Department of Human Neuroscience, “Sapienza” University of Rome, Via dei Sabelli 108, 00185 Rome, Italy
| | - Mara Testa
- Department of Human Neuroscience, “Sapienza” University of Rome, Via dei Sabelli 108, 00185 Rome, Italy
| | - Giovanni Meledandri
- Department of Human Science, “Università degli Studi Guglielmo Marconi”, Via Plinio 44, 00193 Rome, Italy
| | - Claudia Carducci
- Department of Experimental Medicine, Sapienza University of Rome, Viale del policlinico 155, 00161 Rome, Italy
| | - Roberta Penge
- Department of Human Neuroscience, “Sapienza” University of Rome, Via dei Sabelli 108, 00185 Rome, Italy
| | - Vincenzo Leuzzi
- Department of Human Neuroscience, “Sapienza” University of Rome, Via dei Sabelli 108, 00185 Rome, Italy
| |
Collapse
|
28
|
Large Neutral Amino Acids (LNAAs) Supplementation Improves Neuropsychological Performances in Adult Patients with Phenylketonuria. Nutrients 2020; 12:nu12041092. [PMID: 32326614 PMCID: PMC7230959 DOI: 10.3390/nu12041092] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 03/29/2020] [Accepted: 04/10/2020] [Indexed: 11/17/2022] Open
Abstract
Phenylketonuria is an inborn error of phenylalanine (Phe) metabolism diagnosed by newborn screening and treated early with diet. Although diet prevents intellectual disability, patients often show impairment of executive functions, working memory, sustained attention, and cognitive flexibility. Large neutral amino acids (LNAAs) have been proposed as a dietary supplement for PKU adults. Few studies show that LNAAs may help in improving metabolic control as well as cognitive functions. In this study, 10 adult PKU patients with poor metabolic control were treated for 12 months with LNAAs (MovisCom, 0.8–1 g/kg/day) and underwent Phe and Tyrosine (Tyr) monitoring monthly. Neuropsychological assessment was performed at T0, T+3, and T+12 months by using the American Psychological General Well-Being Index, the Wisconsin Card Sorting Test, the Test of Attentional Performance, and the 9-Hole Peg Test. No change in plasma Phe levels was observed during LNAAs supplementation, while Tyr levels significantly improved during LNAAs supplementation (p = 0.03). Psychometric tests showed an improvement of distress and well-being rates, of executive functions, attention, and vigilance, whereas no difference was noted regarding hand dexterity. This study adds evidence of the advantage of LNAAs supplementation in improving cognitive functions and well-being in patients with PKU with poor metabolic control.
Collapse
|
29
|
Borghi L, Moreschi C, Toscano A, Comber P, Vegni E. The PKU & ME study: A qualitative exploration, through co-creative sessions, of attitudes and experience of the disease among adults with phenylketonuria in Italy. Mol Genet Metab Rep 2020; 23:100585. [PMID: 32257816 PMCID: PMC7125347 DOI: 10.1016/j.ymgmr.2020.100585] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 03/27/2020] [Accepted: 03/27/2020] [Indexed: 12/22/2022] Open
Abstract
Background Phenylketonuria (PKU) is a hereditary metabolic disease that can be diagnosed and successfully treated from birth with a lifelong phenylalanine-restricted dietary regimen. However, optimal adherence to diet remains an issue and often progressively decreases after adolescence. The study aimed to explore the experience of adults living with PKU in order to gain insights related to their adherence to diet and engagement in managing their condition. Methods The study adopted a qualitative methodology in sessions that combined specifically designed co-creation exercises with focus group discussion. Adults with early-treated classic PKU were enrolled for 2 different sessions - one for adherent and one for non-adherent patients. The verbatim notes of both sessions and focus group were analyzed using content analysis. Results Twelve adherent and nine non-adherent adults with PKU participated. Besides the behavioral dictates of following a strict diet, adherent adults reported a positive mental approach and organizational rigor; they seemed aware of the consequences of high-phenylalanine levels, reporting that it can affect mood and consequently social interactions which they value highly. In the non-adherent group, the individuals seemed to not fully accept their disease: they were aware of the consequences of non-adherence in children but not in adults, they felt the management of PKU was an individual burden and they experienced a feeling of 'diversity' in the social context (related to eating) that caused emotional distress. PKU seemed a very influential element of the identity both for adherent and non-adherent adults, but with different consequences for the two groups. Finally, all participants reported the desire to be assisted in a healthcare setting dedicated to adults. Conclusions The findings expand the understanding of the psychological experience of adult patients with PKU in relation to their disease and its dietary requirements, highlighting specific factors that might drive tailored educational or psychological intervention to improve adherence and engagement in the care process.
Collapse
Affiliation(s)
- Lidia Borghi
- Clinical Psychology, Department of Health Sciences, University of Milan, Via A. di Rudinì 8, 20142 Milan, Italy
| | - Carlotta Moreschi
- Clinical Psychology, Department of Health Sciences, University of Milan, Via A. di Rudinì 8, 20142 Milan, Italy
| | - Alessandra Toscano
- Atstrat, Consulting Company focused on Co-creation sessions, Patient Support Programmes Design, Via Galllarate 105, 20151 Milan, Italy
| | - Peter Comber
- Atstrat, Consulting Company focused on Co-creation sessions, Patient Support Programmes Design, Via Galllarate 105, 20151 Milan, Italy
| | - Elena Vegni
- Clinical Psychology, Department of Health Sciences, University of Milan, Via A. di Rudinì 8, 20142 Milan, Italy
| |
Collapse
|
30
|
Ferreira BK, Rodrigues MT, Streck EL, Ferreira GC, Schuck PF. White matter disturbances in phenylketonuria: Possible underlying mechanisms. J Neurosci Res 2020; 99:349-360. [PMID: 32141105 DOI: 10.1002/jnr.24598] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 01/09/2020] [Accepted: 02/04/2020] [Indexed: 12/24/2022]
Abstract
White matter pathologies, as well as intellectual disability, microcephaly, and other central nervous system injuries, are clinical traits commonly ascribed to classic phenylketonuria (PKU). PKU is an inherited metabolic disease elicited by the deficiency of phenylalanine hydroxylase. Accumulation of l-phenylalanine (Phe) and its metabolites is found in tissues and body fluids in phenylketonuric patients. In order to mitigate the clinical findings, rigorous dietary Phe restriction constitutes the core of therapeutic management in PKU. Myelination is the process whereby the oligodendrocytes wrap myelin sheaths around the axons, supporting the conduction of action potentials. White matter injuries are implicated in the brain damage related to PKU, especially in untreated or poorly treated patients. The present review summarizes evidence toward putative mechanisms driving the white matter pathology in PKU patients.
Collapse
Affiliation(s)
- Bruna Klippel Ferreira
- Laboratório de Neuroenergética e Erros Inatos do Metabolismo, Programa de Bioquímica e Biofísica Celular, Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Porto Alegre, Brazil
| | - Melissa Torres Rodrigues
- Laboratório de Erros Inatos do Metabolismo, Escola de Ciências da Saúde e da Vida, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil.,Programa de Pós-graduação em Biologia Celular e Molecular, Escola de Ciências da Saúde e da Vida, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil
| | - Emilio Luiz Streck
- Laboratório de Neurologia Experimental, Programa de Pós-Graduação em Ciências da Saúde, Universidade do Extremo Sul Catarinense, Criciúma, Brazil
| | - Gustavo Costa Ferreira
- Laboratório de Neuroenergética e Erros Inatos do Metabolismo, Programa de Bioquímica e Biofísica Celular, Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Porto Alegre, Brazil
| | - Patricia Fernanda Schuck
- Laboratório de Erros Inatos do Metabolismo, Escola de Ciências da Saúde e da Vida, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil.,Programa de Pós-graduação em Biologia Celular e Molecular, Escola de Ciências da Saúde e da Vida, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil
| |
Collapse
|
31
|
Gropman AL, Anderson A. Novel imaging technologies for genetic diagnoses in the inborn errors of metabolism. JOURNAL OF TRANSLATIONAL GENETICS AND GENOMICS 2020; 4:429-445. [PMID: 35529470 PMCID: PMC9075742 DOI: 10.20517/jtgg.2020.09] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Many inborn errors of metabolism and genetic disorders affect the brain. The brain biochemistry may differ from that in the periphery and is not accessible by simple blood and urine sampling. Therefore, neuroimaging has proven to be a valuable tool to not only evaluate the brain structure, but also biochemistry, blood flow and function. Neuroimaging in patients with inborn errors of metabolism can include additional sequences in addition to T1 and T2-weighted imaging because in early stages, there may be no significant findings on the routine sequnces due to the lack of sensitivity or the evolution of abnormalities lags behind the ability of the imaging to detect it. In addition, findings on T1 and T2-weighted imaging of several inborn errors of metabolism may be non-specific and be seen in other non-genetic conditions. Therefore, additional neuroimaging modalities that have been employed including diffusion tensor imaging (DTI), magnetic resonance spectroscopy, functional MRI (fMRI), functional near infrared spectroscopy (fNIRS), or positron emission tomography (PET) imaging may further inform underlying changes in myelination, biochemistry, and functional connectivity. The use of Magnetic Resonance Spectroscopy in certain disorders may add a level of specificity depending upon the metabolite levels that are abnormal, as well as provide information about the process of brain injury (i.e., white matter, gray matter, energy deficiency, toxic buildup or depletion of key metabolites). It is even more challenging to understand how genetic or metabolic disorders contribute to short and/or long term changes in cognition which represent the downstream effects of IEMs. In order to image “cognition” or the downstream effects of a metabolic disorder on domains of brain function, more advanced techniques are required to analyze underlying fiber tracts or alternatively, methods such as fMRI enable generation of brain activation maps after both task based and resting state conditions. DTI can be used to look at changes in white matter tracks. Each imaging modality can explore an important aspect of the anatomy, physiology or biochemisty of the central nervous system. Their properties, pros and cons are discussed in this article. These imaging modalities will be discussed in the context of several inborn errors of metabolism including Galactosemia, Phenylketonruia, Maple syrup urine disease, Methylmalonic acidemia, Niemann-Pick Disease, type C1, Krabbe Disease, Ornithine transcarbamylase deficiency, Sjogren Larsson syndrome, Pelizeaus-Merzbacher disease, Pyruvate dehydrogenase deficiency, Nonketotic Hyperglycinemia and Fabry disease. Space constraints do not allow mention of all the disorders in which one of these modalities has been investigated, or where it would add value to diagnosis or disease progression.
Collapse
Affiliation(s)
- Andrea L Gropman
- Department of Neurology, Children's National Medical Center, Washington, DC 20010, USA
| | - Afrouz Anderson
- Department of Research, Focus Foundation, Crofton, MD 21035, USA
| |
Collapse
|
32
|
Palermo L, MacDonald A, Limback E, Robertson L, Howe S, Geberhiwot T, Romani C. Emotional health in early-treated adults with phenylketonuria (PKU): Relationship with cognitive abilities and blood phenylalanine. J Clin Exp Neuropsychol 2019; 42:142-159. [DOI: 10.1080/13803395.2019.1696753] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Liana Palermo
- School of Life and Health Sciences, Aston University, Birmingham, UK
- Inherited Metabolic Disorders Service, Queen Elizabeth Hospital, Birmingham, UK
- Department of Medical and Surgical Sciences, Magna Graecia University of Catanzaro, Catanzaro, Italy
| | - Anita MacDonald
- Dietetic Department, Birmingham Children’s Hospital, Birmingham, UK
| | - Ellie Limback
- School of Life and Health Sciences, Aston University, Birmingham, UK
| | - Louise Robertson
- Inherited Metabolic Disorders Service, Queen Elizabeth Hospital, Birmingham, UK
| | - Sarah Howe
- Inherited Metabolic Disorders Service, Queen Elizabeth Hospital, Birmingham, UK
| | - Tarekegn Geberhiwot
- Inherited Metabolic Disorders Service, Queen Elizabeth Hospital, Birmingham, UK
| | - Cristina Romani
- School of Life and Health Sciences, Aston University, Birmingham, UK
| |
Collapse
|
33
|
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.
Collapse
|
34
|
Nardecchia F, Manti F, De Leo S, Carducci C, Leuzzi V. Clinical characterization of tremor in patients with phenylketonuria. Mol Genet Metab 2019; 128:53-56. [PMID: 31208951 DOI: 10.1016/j.ymgme.2019.05.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 05/30/2019] [Accepted: 05/31/2019] [Indexed: 11/24/2022]
Abstract
BACKGROUND Phenylketonuria (PKU) is due to the deficit of the enzyme phenylalanine hydroxylase, the first step of dopamine synthesis. If not early treated the disease results in severe neurological impairment. Minor neurological signs have been reported in early treated PKU (ETPKU) subjects. Prolactin level is affected by (and reflects) brain dopamine availability. Object of the study was to assess the occurrence, age at onset, distribution, associated neurological signs, and possible pathogenetic biomarkers of tremor in ETPKU. METHODS Fifty-nine ETPKU and 43 control subjects (age range 7-54) underwent individual and familiar tremor history, clinical assessment of tremor by means of the Fahn-Tolosa-Marin Tremor Rating Scale, and IQ evaluation. Historical and concomitant biochemical data (blood levels of Phe) and serum prolactin were included in the analysis. RESULTS Thirty-two percent of ETPKU patients were affected by postural and kinetic tremor. We found a significant correlation between severity of tremor and: prolactin level at the day of examination (part A: rs = 0.320; p = .014; part C: rs = 0.319; p = .014), Phe fluctuations from 12 years onwards (part B: rs = 0.300; p = .036). We also found a significant correlation between prolactin (18.2 ± 9.6 ng/ml) and Phe levels (852 ± 472 μmol/l) on the day of assessment (rs = 0.470; p < .001). CONCLUSIONS The main clinical features of tremor in ETPKU evoke those of essential tremor, although with a higher prevalence and an earlier onset than in general population. The severity of tremor was related to concomitant prolactin rather than Phe levels. This pattern suggests that metabolic alterations associated with PKU may result in an anticipation of the tremor onset in subjects who are possibly prone to this disorder.
Collapse
Affiliation(s)
| | - Filippo Manti
- Department of Human Neuroscience, Sapienza University of Rome, Italy
| | - Sabrina De Leo
- Department of Internal Medicine and Clinical Nutrition, Sapienza University of Rome, Italy
| | - Claudia Carducci
- Department of Experimental Medicine, Sapienza University of Rome, Italy
| | - Vincenzo Leuzzi
- Department of Human Neuroscience, Sapienza University of Rome, Italy.
| |
Collapse
|
35
|
Couce ML, de Castro MJ, de Lamas C, Leis R. Effects of LC-PUFA Supplementation in Patients with Phenylketonuria: A Systematic Review of Controlled Trials. Nutrients 2019; 11:nu11071537. [PMID: 31284588 PMCID: PMC6682937 DOI: 10.3390/nu11071537] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 07/01/2019] [Accepted: 07/02/2019] [Indexed: 01/13/2023] Open
Abstract
Evidence suggests a role of long chain polyunsaturated fatty acids (LC-PUFA), in which animal foods are especially rich, in optimal neural development. The LC-PUFAs docosahexaenoic acid (DHA) and arachidonic acid, found in high concentrations in the brain and retina, have potential beneficial effects on cognition, and motor and visual functions. Phenylketonuria (PKU) is the most common inborn error of amino acid metabolism. The treatment of PKU consists of a phenylalanine-free diet, which limits the intake of natural proteins of high biological value. In this systematic review, we summarize the available evidence supporting a role for LC-PUFA supplementation as an effective means of increasing LC-PUFA levels and improving visual and neurocognitive functions in PKU patients. Data from controlled trials of children and adults (up to 47 years of age) were obtained by searching the MEDLINE and SCOPUS databases following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. For each selected study, the risk of bias was assessed applying the methodology of the Cochrane Collaboration. The findings indicate that DHA supplementation in PKU patients from 2 weeks to 47 years of age improves DHA status and decreases visual evoked potential P100 wave latency in PKU children from 1 to 11 years old. Neurocognitive data are inconclusive.
Collapse
Affiliation(s)
- María Luz Couce
- Department of Pediatrics, University Clinical Hospital of Santiago de Compostela, 15706 Santiago de Compostela, Spain.
- IDIS-Health Research Institute of Santiago de Compostela, 15706 Santiago de Compostela, Spain.
- CIBERER, Pabellón 11, 28029 Madrid, Spain.
- Universidade de Santiago de Compostela, 15704 Santiago de Compostela, Spain.
| | - María José de Castro
- Department of Pediatrics, University Clinical Hospital of Santiago de Compostela, 15706 Santiago de Compostela, Spain
- IDIS-Health Research Institute of Santiago de Compostela, 15706 Santiago de Compostela, Spain
- CIBERER, Pabellón 11, 28029 Madrid, Spain
| | - Carmela de Lamas
- CIBERER, Pabellón 11, 28029 Madrid, Spain
- Universidade de Santiago de Compostela, 15704 Santiago de Compostela, Spain
- Department of Pediatrics, Pediatric Metabolism and Research Unit, Reina Sofia University Hospital, IMIBIC, 14004 Cordoba, Spain
| | - Rosaura Leis
- Department of Pediatrics, University Clinical Hospital of Santiago de Compostela, 15706 Santiago de Compostela, Spain
- IDIS-Health Research Institute of Santiago de Compostela, 15706 Santiago de Compostela, Spain
- CIBERER, Pabellón 11, 28029 Madrid, Spain
- Universidade de Santiago de Compostela, 15704 Santiago de Compostela, Spain
| |
Collapse
|
36
|
Hawks Z, Hood AM, Lerman-Sinkoff DB, Shimony JS, Rutlin J, Lagoni D, Grange DK, White DA. White and gray matter brain development in children and young adults with phenylketonuria. NEUROIMAGE-CLINICAL 2019; 23:101916. [PMID: 31491833 PMCID: PMC6627563 DOI: 10.1016/j.nicl.2019.101916] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 05/09/2019] [Accepted: 06/29/2019] [Indexed: 12/27/2022]
Abstract
Phenylketonuria (PKU) is a recessive disorder characterized by disruption in the metabolism of the amino acid phenylalanine (Phe). Prior research indicates that individuals with PKU have substantial white matter (WM) compromise. Much less is known about gray matter (GM) in PKU, but a small body of research suggests volumetric differences compared to controls. To date, developmental trajectories of GM structure in individuals with PKU have not been examined, nor have trajectories of WM and GM been examined within a single study. To address this gap in the literature, we compared longitudinal brain development over a three-year period in individuals with PKU (n = 35; 18 male) and typically-developing controls (n = 71; 35 male) aged 7–21 years. Using diffusion tensor imaging (DTI) and structural magnetic resonance imaging (MRI), we observed whole-brain and regional WM differences between individuals with PKU and controls, which were often exacerbated with increasing age. In marked contrast with trajectories of WM development, trajectories of GM development did not differ between individuals with PKU and controls, indicating that neuropathology in PKU is more prominent in WM than GM. Within individuals with PKU, mediation analyses revealed that whole-brain mean diffusivity (MD) and regional MD in the corpus callosum and centrum semiovale mediated the relationship between dietary treatment compliance (i.e., Phe control) and executive abilities, suggesting a plausible neurobiological mechanism by which Phe control may influence cognitive outcomes. Our findings clarify the specificity, timing, and cognitive consequences of whole-brain and regional WM pathology, with implications for treatment and research in PKU. Individuals with PKU exhibited widespread, age-related white matter compromise. Developmental trajectories of gray matter were comparable for PKU and controls. Within PKU, white matter compromise influenced cognitive outcomes.
Collapse
Affiliation(s)
- Zoë Hawks
- Department of Psychological & Brain Sciences, Campus Box 1125, Washington University, St. Louis, MO, United States.
| | - Anna M Hood
- Department of Psychological & Brain Sciences, Campus Box 1125, Washington University, St. Louis, MO, United States.
| | - Dov B Lerman-Sinkoff
- Department of Psychological & Brain Sciences, Campus Box 1125, Washington University, St. Louis, MO, United States; Department of Biomedical Engineering, Washington University, St. Louis, MO, United States
| | - Joshua S Shimony
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, United States
| | - Jerrel Rutlin
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, United States
| | - Daniel Lagoni
- Department of Psychological & Brain Sciences, Campus Box 1125, Washington University, St. Louis, MO, United States
| | - Dorothy K Grange
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, United States
| | - Desirée A White
- Department of Psychological & Brain Sciences, Campus Box 1125, Washington University, St. Louis, MO, United States; Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, United States
| |
Collapse
|
37
|
Neuropsychological Profile of Children with Early and Continuously Treated Phenylketonuria: Systematic Review and Future Approaches. J Int Neuropsychol Soc 2019; 25:624-643. [PMID: 31030702 DOI: 10.1017/s1355617719000146] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
OBJECTIVE To provide a comprehensive systematic review of the literature by examining studies published on all cognitive aspects of children with early and continuously treated phenylketonuria (ECT-PKU) included in the databases Medline, PsycINFO, and PsycARTICLE. METHOD In addition to a classical approach, we summarized methodology and results of each study in order to discuss current theoretical and methodological issues. We also examined recent advances in biochemical markers and treatments of PKU, with implications for future research on metabolic control and its role as a determinant of neuropsychological outcome. RESULTS Consistent with previous reviews, the hypothesis of a specific and central executive impairment in children with ECT-PKU was suggested. However, findings are inconclusive regarding the nature of executive impairments as well as their specificity, impact on everyday life, persistence over time, and etiology. CONCLUSION Given the current state of the science, we suggest future directions for research that utilizes a developmental and integrative approach to examine the effects of recent advances in biochemical markers and treatment of PKU. (JINS, 2019, 25, 624-643).
Collapse
|
38
|
Burlina AP, Lachmann RH, Manara R, Cazzorla C, Celato A, van Spronsen FJ, Burlina A. The neurological and psychological phenotype of adult patients with early-treated phenylketonuria: A systematic review. J Inherit Metab Dis 2019; 42:209-219. [PMID: 30690773 DOI: 10.1002/jimd.12065] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 01/21/2019] [Indexed: 11/11/2022]
Abstract
Newborn screening for phenylketonuria (PKU) and early introduction of dietary therapy has been remarkably successful in preventing the severe neurological features of PKU, including mental retardation and epilepsy. However, concerns remain that long-term outcome is still suboptimal, particularly in adult patients who are no longer on strict phenylalanine-restricted diets. With our systematic literature review we aimed to describe the neurological phenotype of adults with early-treated phenylketonuria (ETPKU). The literature search covered the period from 1 January 1990 up to 16 April 2018, using the NLM MEDLINE controlled vocabulary. Of the 643 records initially identified, 83 were included in the analysis. The most commonly reported neurological signs were tremor and hyperreflexia. The overall quality of life (QoL) of ETPKU adults was good or comparable to control populations, and there was no evidence for a significant incidence of psychiatric disease or social difficulties. Neuroimaging revealed that brain abnormalities are present in ETPKU adults, but their clinical significance remains unclear. Generally, intelligence quotient (IQ) appears normal but specific deficits in neuropsychological and social functioning were reported in early-treated adults compared with healthy individuals. However, accurately defining the prevalence of these deficits is complicated by the lack of standardized neuropsychological tests. Future research should employ standardized neurological, neuropsychological, and neuroimaging protocols, and consider other techniques such as advanced imaging analyses and the recently validated PKU-specific QoL questionnaire, to precisely define the nature of the impairments within the adult ETPKU population and how these relate to metabolic control throughout life.
Collapse
Affiliation(s)
| | - Robin H Lachmann
- Charles Dent Metabolic Unit, National Hospital for Neurology and Neurosurgery, London, UK
| | - Renzo Manara
- Department of Medicine and Surgery, University of Salerno, Salerno, Italy
| | - Chiara Cazzorla
- Division of Inborn Metabolic Diseases, Department of Paediatrics, University Hospital, Padua, Italy
| | - Andrea Celato
- Division of Inborn Metabolic Diseases, Department of Paediatrics, University Hospital, Padua, Italy
| | - Francjan J van Spronsen
- Division of Metabolic Diseases, Beatrix Children's Hospital, University Medical Center of Groningen, University of Groningen, Groningen, The Netherlands
| | - Alberto Burlina
- Division of Inborn Metabolic Diseases, Department of Paediatrics, University Hospital, Padua, Italy
| |
Collapse
|
39
|
Rocha JC, MacDonald A. Treatment options and dietary supplements for patients with phenylketonuria. Expert Opin Orphan Drugs 2018. [DOI: 10.1080/21678707.2018.1536541] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Júlio César Rocha
- Centro de Genética Médica, Centro Hospitalar do Porto - CHP, Porto, Portugal
- Faculdade de Ciências da Saúde, Universidade Fernando Pessoa, Porto, Portugal
- Center for Health Technology and Services Research (CINTESIS), Porto, Portugal
| | | |
Collapse
|
40
|
Bartus A, Palasti F, Juhasz E, Kiss E, Simonova E, Sumanszki C, Reismann P. The influence of blood phenylalanine levels on neurocognitive function in adult PKU patients. Metab Brain Dis 2018; 33:1609-1615. [PMID: 29948654 DOI: 10.1007/s11011-018-0267-6] [Citation(s) in RCA: 15] [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: 02/11/2018] [Accepted: 06/06/2018] [Indexed: 10/14/2022]
Abstract
It is well known that hyperphenylalaninemia caused by phenylketonuria (PKU) negatively influences cognitive performance. Several tests have been used to study these functions. Until now, no universal, optimal tool has been developed for detecting PKU-caused brain dysfunctions. Using computerized neuropsychological tests during daily routine would be helpful for screening subclinical brain deficits in adult PKU patients. In a monocentric, cross-sectional study, adult patients with PKU (n = 46; median age = 29.5 years; female/male ratio = 21/25) were tested with the computerized Cambridge Cognition (CANTAB) test measuring neurocognitive functions. Patients were divided into two groups: The "on diet" group included patients whose blood Phe-level was under 600 μmol/l (n = 20), and the "loose diet" group included patients whose blood Phe-level was above 600 μmol/l (n = 26) at the examination time. The results of the PKU-affected individuals were compared with a healthy control group (n = 31; median age = 25 years; female/male ratio = 11/20). Compared with the control group, PKU patients had significantly worse test results in memory, problem-solving skills, and strategy. However, there were no significant differences in response speed or initial thinking time. There was no correlation between the blood Phe-level, tyrosine (Tyr)-level or Phe/Tyr ratio and the different cognitive test results. There were no significant differences in test results between the two PKU subgroups. Several cognitive functions measured by CANTAB are negatively influenced by hyperphenylalaninemia in adult PKU patients. However, response speed and initial thinking time were not impaired as seriously as other functions. Patients with lower Phe-levels failed to achieve better test results than patients whose Phe-levels were notably elevated.
Collapse
Affiliation(s)
- A Bartus
- 2nd Department of Internal Medicine, Semmelweis University, Szentkirályi Street 46, Budapest, H-1088, Hungary
| | - F Palasti
- 2nd Department of Internal Medicine, Semmelweis University, Szentkirályi Street 46, Budapest, H-1088, Hungary
| | - E Juhasz
- 2nd Department of Internal Medicine, Semmelweis University, Szentkirályi Street 46, Budapest, H-1088, Hungary
| | - E Kiss
- 1st Department of Pediatrics, Semmelweis University, Bókay János u. 53-54, Budapest, H-1083, Hungary
| | - E Simonova
- 1st Department of Pediatrics, Semmelweis University, Bókay János u. 53-54, Budapest, H-1083, Hungary
| | - Cs Sumanszki
- 2nd Department of Internal Medicine, Semmelweis University, Szentkirályi Street 46, Budapest, H-1088, Hungary
| | - P Reismann
- 2nd Department of Internal Medicine, Semmelweis University, Szentkirályi Street 46, Budapest, H-1088, Hungary.
| |
Collapse
|
41
|
Cazzorla C, Bensi G, Biasucci G, Leuzzi V, Manti F, Musumeci A, Papadia F, Stoppioni V, Tummolo A, Vendemiale M, Polo G, Burlina A. Living with phenylketonuria in adulthood: The PKU ATTITUDE study. Mol Genet Metab Rep 2018; 16:39-45. [PMID: 30069431 PMCID: PMC6066799 DOI: 10.1016/j.ymgmr.2018.06.007] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 06/27/2018] [Indexed: 12/27/2022] Open
Abstract
Dietary treatment is the cornerstone of therapy for phenylketonuria (PKU), but adherence to low- phenylalanine diet progressively decreases after adolescence. We designed a survey to characterize the dietary habits of Italian adult PKU patients and to identify psychological factors influencing disease perception and adherence to diet. Participants to the survey (n = 111; response rate 94%) were asked to complete a structured questionnaire. Patients appeared to have an altered perception and awareness of the disease. About 40% of them did not consider PKU a disease and, despite declaring regular monitoring of phenylalanine levels (85%), nearly half of them reported a high plasma value over the last 6 months (>600 μmol/L, 48%) or were unable to specify it (31%). Adherence to PKU diet was unsatisfactory, with increased consumption of natural protein sources and reduced daily use of amino-acid supplements (<4-5 times/day in 82% patients). In addition to the intrinsic characteristics of AA formula (palatability, ease of use), the most important factor influencing their consumption was the increased social pressure associated with their use (55%). Plasma phenylalanine periodical measurements (61%) and examinations at metabolic centers (49%) were considered relevant for compliance to diet. In Italian adult PKU patients dietary management was found to be inadequate, likely due to inappropriate perception and knowledge of the disease, and lack of awareness of the negative impact of poor metabolic control in adult life. Clinicians should consider implementing more intense and tailored educational measures, as well as structured transitional care processes.
Collapse
Affiliation(s)
- Chiara Cazzorla
- Division of Inherited Metabolic Diseases, Reference Centre Expanded Newborn Screening, Department of Woman's and Child's Health - University Hospital, Padova, Italy
| | - Giulia Bensi
- Department of Pediatrics and Neonatology, Regional Referral Clinical Centre for IMD, Guglielmo da Saliceto Hospital, Piacenza, Italy
| | - Giacomo Biasucci
- Department of Pediatrics and Neonatology, Regional Referral Clinical Centre for IMD, Guglielmo da Saliceto Hospital, Piacenza, Italy
| | - Vincenzo Leuzzi
- Department of Human Neuroscience, Child Neurology and Psychiatry - Sapienza University, Rome, Italy
| | - Filippo Manti
- Department of Human Neuroscience, Child Neurology and Psychiatry - Sapienza University, Rome, Italy
| | - Antonella Musumeci
- Division of Child Neurology and Psychiatry, Riuniti Hospital Marche Nord Pesaro, Fano, Italy
| | - Francesco Papadia
- Department of Metabolic Diseases, Clinical Genetics and Diabetology, Giovanni XXIII Children's Hospital, Bari, Italy
| | - Vera Stoppioni
- Division of Child Neurology and Psychiatry, Riuniti Hospital Marche Nord Pesaro, Fano, Italy
| | - Albina Tummolo
- Department of Metabolic Diseases, Clinical Genetics and Diabetology, Giovanni XXIII Children's Hospital, Bari, Italy
| | - Marcella Vendemiale
- Department of Metabolic Diseases, Clinical Genetics and Diabetology, Giovanni XXIII Children's Hospital, Bari, Italy
| | - Giulia Polo
- Division of Inherited Metabolic Diseases, Reference Centre Expanded Newborn Screening, Department of Woman's and Child's Health - University Hospital, Padova, Italy
| | - Alberto Burlina
- Division of Inherited Metabolic Diseases, Reference Centre Expanded Newborn Screening, Department of Woman's and Child's Health - University Hospital, Padova, Italy
| |
Collapse
|
42
|
Hofman DL, Champ CL, Lawton CL, Henderson M, Dye L. A systematic review of cognitive functioning in early treated adults with phenylketonuria. Orphanet J Rare Dis 2018; 13:150. [PMID: 30165883 PMCID: PMC6117942 DOI: 10.1186/s13023-018-0893-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 08/16/2018] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND Even though early dietary management of phenylketonuria (PKU) successfully prevents severe neurological impairments, deficits in cognitive functioning are still observed. These deficits are believed to be the result of elevated levels of phenylalanine throughout life. Research on cognitive functioning in adults with PKU (AwPKU) often focuses on domains shown to be compromised in children with PKU, such as attention and executive functions, whereas other cognitive domains have received less attention. This systematic review aimed to provide an overview of cognitive functioning across domains examined in early treated (ET) AwPKU. METHODS A systematic search was performed in Ovid MEDLINE(R), PsycINFO, Web of Science, Cochrane, Scopus, Embase, ScienceDirect, and PubMed for observational studies on cognitive performance in ET AwPKU. RESULTS Twenty-two peer-reviewed publications, reporting on outcomes from 16 studies were reviewed. Collectively, the results most consistently showed deficits in vigilance, working memory and motor skills. Deficits in other cognitive domains were less consistently observed or were understudied. Furthermore, despite reports of several associations between cognitive performance and phenylalanine (Phe) levels throughout life the relationship remains unclear. Inconsistencies in findings across studies could be explained by the highly heterogeneous nature of study samples, resulting in large inter- and intra-variability in Phe levels, as well as the use of a variety of tests across cognitive domains, which differ in sensitivity. The long-term cognitive outcomes of early and continuous management of PKU remain unclear. CONCLUSIONS To better understand the development of cognitive deficits in ET AwPKU, future research would benefit from 1) (inter)national multicentre-studies; 2) more homogeneous study samples; 3) the inclusion of other nutritional measures that might influence cognitive functioning (e.g. Phe fluctuations, Phe:Tyrosine ratio and micronutrients such as vitamin B12); and 4) careful selection of appropriate cognitive tests.
Collapse
Affiliation(s)
| | | | | | - Mick Henderson
- Biochemical Genetics, Specialist Laboratory Medicine, St James’s University Hospital, Block 46, Leeds, LS9 7TF UK
| | - Louise Dye
- School of Psychology, University of Leeds, Leeds, LS2 9JT UK
| |
Collapse
|
43
|
Nardecchia F, Orlando R, Iacovelli L, Colamartino M, Fiori E, Leuzzi V, Piccinin S, Nistico R, Puglisi-Allegra S, Di Menna L, Battaglia G, Nicoletti F, Pascucci T. Targeting mGlu5 Metabotropic Glutamate Receptors in the Treatment of Cognitive Dysfunction in a Mouse Model of Phenylketonuria. Front Neurosci 2018; 12:154. [PMID: 29615849 PMCID: PMC5864888 DOI: 10.3389/fnins.2018.00154] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 02/26/2018] [Indexed: 11/23/2022] Open
Abstract
We studied group-I metabotropic glutamate (mGlu) receptors in Pahenu2 (ENU2) mice, which mimic the genetics and neurobiology of human phenylketonuria (PKU), a metabolic disorder characterized, if untreated, by autism, and intellectual disability (ID). Male ENU2 mice showed increased mGlu5 receptor protein levels in the hippocampus and corpus striatum (but not in the prefrontal cortex) whereas the transcript of the mGlu5 receptor was unchanged. No changes in mGlu1 receptor mRNA and protein levels were found in any of the three brain regions of ENU2 mice. We extended the analysis to Homer proteins, which act as scaffolds by linking mGlu1 and mGlu5 receptors to effector proteins. Expression of the long isoforms of Homer was significantly reduced in the hippocampus of ENU2 mice, whereas levels of the short Homer isoform (Homer 1a) were unchanged. mGlu5 receptors were less associated to immunoprecipitated Homer in the hippocampus of ENU2 mice. The lack of mGlu5 receptor-mediated long-term depression (LTD) in wild-type mice (of BTBR strain) precluded the analysis of hippocampal synaptic plasticity in ENU2 mice. We therefore performed a behavioral analysis to examine whether pharmacological blockade of mGlu5 receptors could correct behavioral abnormalities in ENU2 mice. Using the same apparatus we sequentially assessed locomotor activity, object exploration, and spatial object recognition (spatial novelty test) after displacing some of the objects from their original position in the arena. Systemic treatment with the mGlu5 receptor antagonist, MPEP (20 mg/kg, i.p.), had a striking effect in the spatial novelty test by substantially increasing the time spent in exploring the displaced objects in ENU2 mice (but not in wild-type mice). These suggest a role for mGlu5 receptors in the pathophysiology of ID in PKU and suggest that, also in adult untreated animals, cognitive dysfunction may be improved by targeting these receptors with an appropriate therapy.
Collapse
Affiliation(s)
- Francesca Nardecchia
- Department of Physiology and Pharmacology, Sapienza Università di Roma, Rome, Italy.,Department of Pediatrics and Child Neuropsychiatry, Sapienza Università di Roma, Rome, Italy
| | - Rosamaria Orlando
- Department of Physiology and Pharmacology, Sapienza Università di Roma, Rome, Italy
| | - Luisa Iacovelli
- Department of Physiology and Pharmacology, Sapienza Università di Roma, Rome, Italy
| | - Marco Colamartino
- Daniel Bovet Department of Psychology, Neurobiology Research Center, Sapienza Università di Roma, Rome, Italy
| | - Elena Fiori
- Daniel Bovet Department of Psychology, Neurobiology Research Center, Sapienza Università di Roma, Rome, Italy
| | - Vincenzo Leuzzi
- Department of Pediatrics and Child Neuropsychiatry, Sapienza Università di Roma, Rome, Italy
| | - Sonia Piccinin
- Department of Physiology and Pharmacology, Sapienza Università di Roma, Rome, Italy.,Department of Biology, Università degli Studi di Roma Tor Vergata, Rome, Italy
| | - Robert Nistico
- Department of Biology, Università degli Studi di Roma Tor Vergata, Rome, Italy
| | - Stefano Puglisi-Allegra
- Daniel Bovet Department of Psychology, Neurobiology Research Center, Sapienza Università di Roma, Rome, Italy.,IRCCS Foundation Santa Lucia, Rome, Italy
| | | | | | - Ferdinando Nicoletti
- Department of Physiology and Pharmacology, Sapienza Università di Roma, Rome, Italy.,IRCCS Neuromed, Pozzilli, Italy
| | - Tiziana Pascucci
- Daniel Bovet Department of Psychology, Neurobiology Research Center, Sapienza Università di Roma, Rome, Italy.,IRCCS Foundation Santa Lucia, Rome, Italy
| |
Collapse
|
44
|
Loe BS, Rust J. The Perceptual Maze Test Revisited: Evaluating the Difficulty of Automatically Generated Mazes. Assessment 2017; 26:1524-1539. [PMID: 29239208 DOI: 10.1177/1073191117746501] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The Elithorn perceptual maze test is widely used in clinical research and practice. However, there is little evidence of its psychometric properties, and its application is limited by the technical difficulty of developing more mazes. The current research aims to adopt a rigorous approach to evaluate 18 mazes that were automatically generated by a novel R software package. Various item response theory models were employed to examine the difficulty parameters. The findings suggested that the data best fitted the Rasch model. The linear logistic test model revealed meaningful contribution to the sources of maze difficulty. Additionally, the linear logistic test model plus error was considered the most parsimonious model. The Automatic Perceptual Maze Test was moderately correlated with a nonverbal intelligence test. By introducing more mazes to provide adequate information on participants' ability at all levels, the Automatic Perceptual Maze Test promises future clinical and research utility for the study of cognitive performance.
Collapse
Affiliation(s)
| | - John Rust
- University of Cambridge, Cambridge, UK
| |
Collapse
|
45
|
Bisiacchi P, Mento G, Tarantino V, Burlina A. Subclinical executive function impairment in children with asymptomatic, treated phenylketonuria: A comparison with children with immunodeficiency virus. Cogn Neuropsychol 2017; 35:200-208. [PMID: 29117799 DOI: 10.1080/02643294.2017.1396207] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
In this study we compared the neuropsychological profile of phenylketonuria (PKU) and human immunodeficiency virus (HIV) to examine the specificity of the executive function (EF) impairment reported in these two patologies. A total of 55 age-matched children and adolescents were assessed, including 11 patients with PKU, 16 patients with HIV and 28 healthy controls, underwent a neuropsychological assessment. Although neither the PKU nor the HIV group scored below the normative ranges, both groups showed lower scores in neuropsychological tests engaging EFs than controls. In addition, compared to patients with PKU the HIV group performed significantly worse in the Trail-Making Test A, Corsi Span and Verbal Fluency. These findings suggest that EF impairments in PKU (a) are limited to EFs (i.e., working memory and attentional shifting), (b) are not simply due to generalized processing speed deficits and
Collapse
Affiliation(s)
- Patrizia Bisiacchi
- a Department of General Psychology , University of Padua , Padua , Italy
| | - Giovanni Mento
- a Department of General Psychology , University of Padua , Padua , Italy
| | | | - Alberto Burlina
- c Division of Inherited Metabolic Diseases , University Hospital Padua
| |
Collapse
|
46
|
Manti F, Nardecchia F, Paci S, Chiarotti F, Carducci C, Carducci C, Dalmazzone S, Cefalo G, Salvatici E, Banderali G, Leuzzi V. Predictability and inconsistencies in the cognitive outcome of early treated PKU patients. J Inherit Metab Dis 2017; 40:793-799. [PMID: 28836033 DOI: 10.1007/s10545-017-0082-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 08/03/2017] [Accepted: 08/03/2017] [Indexed: 01/30/2023]
Abstract
Long-term cognitive outcome and treatment of adult early treated (ET)PKU patients is a main issue in PKU research. We questioned whether the intellectual development of ETPKU patients is stable and to what extent its variation may be predicted by the quality of metabolic control. The aims of the present longitudinal retrospective study were to assess in young adult ETPKU patients: i) the relationship between IQ and metabolic control during the first two decades of life; and ii) the intra- and interindividual variability in the developmental trajectory which cannot be predicted by the disease's biomarkers. We collected biochemical data from 65 ETPKU patients (diagnostic blood Phe > 360 μmol/l) who were assessed twice for IQ (Wechsler Intelligence Scale) during their lifetime (mean age: 10.2 and 19.6 years, respectively). Results show that in ETPKU patients IQ over the second decade of life remained stable in about half of the patients (51%); while the rest experienced a gain (7 to 15 points) or loss (7 to 28 points) in IQ scores (23 and 26% respectively) whatever the quality of metabolic control was. The main factor affecting the second IQ was the value of the first IQ (p < 0.000) whose effect overruled that of the markers of metabolic control. Looking at the developmental trajectory of our ETPKU patients, the present study disclosed a remarkable interindividual variability in their cognitive outcome and also an inconsistent linkage between cognitive performances and biochemical control, thus supporting the hypothesis of an individual resilience or vulnerability to Phe in young adult ETPKU.
Collapse
Affiliation(s)
- Filippo Manti
- Department of Pediatrics and Child Neurology and Psychiatry, Sapienza University of Rome, Via dei Sabelli 108, 00185, Rome, Italy
| | - Francesca Nardecchia
- Department of Pediatrics and Child Neurology and Psychiatry, Sapienza University of Rome, Via dei Sabelli 108, 00185, Rome, Italy
| | - Sabrina Paci
- Department of Pediatrics, University of Milan, San Paolo Hospital, Santi Paolo e Carlo ASST, Via Antonio Di Rudinì 8, 20142, Milan, Italy
| | - Flavia Chiarotti
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Rome, Italy
| | - Claudia Carducci
- Department of Experimental Medicine, Sapienza University of Rome, Viale del Policlinico 155, 00161, Rome, Italy
| | - Carla Carducci
- Department of Experimental Medicine, Sapienza University of Rome, Viale del Policlinico 155, 00161, Rome, Italy
| | - Silvia Dalmazzone
- Department of Pediatrics, University of Milan, San Paolo Hospital, Santi Paolo e Carlo ASST, Via Antonio Di Rudinì 8, 20142, Milan, Italy
| | - Graziella Cefalo
- Department of Pediatrics, University of Milan, San Paolo Hospital, Santi Paolo e Carlo ASST, Via Antonio Di Rudinì 8, 20142, Milan, Italy
| | - Elisabetta Salvatici
- Department of Pediatrics, University of Milan, San Paolo Hospital, Santi Paolo e Carlo ASST, Via Antonio Di Rudinì 8, 20142, Milan, Italy
| | - Giuseppe Banderali
- Department of Pediatrics, University of Milan, San Paolo Hospital, Santi Paolo e Carlo ASST, Via Antonio Di Rudinì 8, 20142, Milan, Italy
| | - Vincenzo Leuzzi
- Department of Pediatrics and Child Neurology and Psychiatry, Sapienza University of Rome, Via dei Sabelli 108, 00185, Rome, Italy.
| |
Collapse
|
47
|
Romani C, Palermo L, MacDonald A, Limback E, Hall SK, Geberhiwot T. The impact of phenylalanine levels on cognitive outcomes in adults with phenylketonuria: Effects across tasks and developmental stages. Neuropsychology 2017; 31:242-254. [PMID: 28240926 PMCID: PMC5331922 DOI: 10.1037/neu0000336] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Objective: Phenylketonuria (PKU) is due to an inability to metabolize the amino acid phenylalanine (Phe), leading to its accumulation in the brain. Phe levels can be controlled following a protein-free diet, but cognitive impairments are still present. A number of questions remain to be answered related to which type of metabolic control is important, the age when it is important, the cognitive functions which are most affected and, the best tests to use to monitor cognitive health. Method: We investigated the impact of metabolic control at different ages on cognitive performance in 37 early treated adults with PKU. Results: (a) Phe variation was as associated to performance as average Phe showing that stable dietary control is as important as strict control; (b) For some tasks, current and adult Phe were stronger predictors of performance than childhood or adolescent Phe, showing the importance of a strict diet even in adulthood; and (c) The relationship between performance and Phe levels varied depending on time and cognitive domain. For some functions (sustained attention, visuomotor coordination), Phe at the time of testing was the best predictor. While for other functions (visual attention, executive functions) there was a diminishing or stable relationship across time. Conclusion: Results show the importance of selecting the right tasks to monitor outcomes across ages, but also that the impact of bio-chemical disruptions is different for different functions, at different ages. We show how inherited metabolic diseases offer us a unique vantage point to inform our understanding of brain development and functioning.
Collapse
Affiliation(s)
| | - Liana Palermo
- School of Life and Health Sciences, Aston University
| | | | - Ellie Limback
- School of Life and Health Sciences, Aston University
| | | | | |
Collapse
|
48
|
Jahja R, van Spronsen FJ, de Sonneville LMJ, van der Meere JJ, Bosch AM, Hollak CEM, Rubio-Gozalbo ME, Brouwers MCGJ, Hofstede FC, de Vries MC, Janssen MCH, van der Ploeg AT, Langendonk JG, Huijbregts SCJ. Long-Term Follow-Up of Cognition and Mental Health in Adult Phenylketonuria: A PKU-COBESO Study. Behav Genet 2017; 47:486-497. [PMID: 28776207 PMCID: PMC5574956 DOI: 10.1007/s10519-017-9863-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Accepted: 07/07/2017] [Indexed: 11/25/2022]
Abstract
Cognitive and mental health problems in individuals with the inherited metabolic disorder phenylketonuria (PKU) have often been associated with metabolic control and its history. For the present study executive functioning (EF) was assessed in 21 PKU patients during childhood (T1, mean age 10.4 years, SD = 2.0) and again in adulthood (T2, mean age 25.8 years, SD = 2.3). At T2 additional assessments of EF in daily life and mental health were performed. Childhood (i.e. 0–12 years) blood phenylalanine was significantly related to cognitive flexibility, executive motor control, EF in daily life and mental health in adulthood (i.e. at T2). Patients with a greater increase in phenylalanine levels after the age of 12 performed more poorly on EF-tasks at T2. Group-based analyses showed that patients with phenylalanine <360 µmol/L in childhood and phenylalanine ≥360 µmol/L from age 13 onwards (n = 11) had better cognitive flexibility and executive motor control than those who had phenylalanine ≥360 µmol/L throughout life (n = 7), supporting the notion that phenylalanine should be below the recommended upper treatment target of 360 µmol/L during childhood for better outcome in adulthood. Despite some results indicating additional influence of phenylalanine levels between 13 and 17 years of age, evidence for a continued influence of phenylalanine levels after childhood on adult outcomes was largely lacking. This may be explained by the fact that the patients in the present study had relatively low phenylalanine levels during childhood (mean: 330 µmol/L, range: 219–581 µmol/L) and thereafter (mean Index of Dietary Control at T2: 464 µmol/L, range: 276–743 µmol/L), which may have buffered against transitory periods of poor metabolic control during adolescence and early adulthood.
Collapse
Affiliation(s)
- Rianne Jahja
- University of Groningen, University Medical Center Groningen, Beatrix Children's Hospital, Groningen, The Netherlands
| | - Francjan J van Spronsen
- University of Groningen, University Medical Center Groningen, Beatrix Children's Hospital, Groningen, The Netherlands.
| | - Leo M J de Sonneville
- Department of Clinical Child and Adolescent Studies & Leiden Institute for Brain and Cognition, Leiden University, Leiden, The Netherlands
| | - Jaap J van der Meere
- University of Groningen, Department of Developmental and Clinical Neuropsychology, Groningen, The Netherlands
| | | | | | - M Estela Rubio-Gozalbo
- University Hospital Maastricht and Laboratory Genetic Metabolic Diseases, Maastricht, The Netherlands
| | - Martijn C G J Brouwers
- Division of Endocrinology and Metabolic Diseases, Department of Internal Medicine, University Hospital Maastricht, Maastricht, The Netherlands
| | - Floris C Hofstede
- Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Maaike C de Vries
- University Medical Center St Radboud Nijmegen, Nijmegen, The Netherlands
| | - Mirian C H Janssen
- University Medical Center St Radboud Nijmegen, Nijmegen, The Netherlands
| | - Ans T van der Ploeg
- Center for Lysosomal and Metabolic Diseases, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Janneke G Langendonk
- Center for Lysosomal and Metabolic Diseases, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Stephan C J Huijbregts
- Department of Clinical Child and Adolescent Studies & Leiden Institute for Brain and Cognition, Leiden University, Leiden, The Netherlands.,Department of Clinical Child and Adolescent Studies, Leiden University, Wassenaarseweg 52, P.O. Box 9555, 2300 RB, Leiden, The Netherlands
| |
Collapse
|
49
|
Nardecchia F, Chiarotti F, Carducci C, Santagata S, Valentini G, Angeloni A, Blau N, Leuzzi V. Altered tetrahydrobiopterin metabolism in patients with phenylalanine hydroxylase deficiency. Eur J Pediatr 2017; 176:917-924. [PMID: 28540433 DOI: 10.1007/s00431-017-2932-x] [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: 03/03/2017] [Revised: 05/11/2017] [Accepted: 05/15/2017] [Indexed: 10/19/2022]
Abstract
The tetrahydrobiopterin (BH4) cofactor is essential for the activity of various enzymes, including phenylalanine (Phe) hydroxylase. In phenylketonuria (PKU) patients, who are chronically exposed to high Phe levels, high urinary excretion of BH4 metabolites neopterin and biopterin is observed. The aim of this longitudinal study was to investigate consistence and variability of the urinary excretion of pterins (neopterin and biopterin) in PKU patients in relation to age and concomitant blood Phe and tyrosine levels. The study was based on the result of 274 pterin examinations (3-13 exams per subject) performed in 47 PKU patients (aged 6 days to 37 years). Multivariate analysis showed that urinary biopterin and neopterin excretion was affected by age and concomitant blood Phe concentration. The influence of blood Phe on both biopterin and neopterin levels was greater in patients younger than 4 months. Later on, interindividual variability was higher than intraindividual variability for both biopterin and neopterin. CONCLUSION Common metabolic (blood Phe levels) and individual (age) factors implicated in the assessment of PKU outcome account only marginally and transiently for the variability of neopterin and biopterin excretion in PKU patients. Other unknown homeostatic factors may probably affect the individual response to chronically elevated Phe levels. What is Known: • In PKU patients, a high urinary excretion of biopterin and neopterin is found. • Biopterin and neopterin excretion is influenced by age and phenylalanine levels. W hat is New: • Blood phenylalanine concentration is the major determinant on pterin excretion in PKU patients in the first months of life. • In older PKU patients, the influence of phenylalanine on pterin excretion is less prominent.
Collapse
Affiliation(s)
- Francesca Nardecchia
- Department of Pediatrics, Child Neurology and Psychiatry, SAPIENZA University of Rome, Via dei Sabelli 108, 00185, Rome, Italy
| | - Flavia Chiarotti
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Rome, Italy
| | - Claudia Carducci
- Department of Experimental Medicine, SAPIENZA University of Rome, Viale del Policlinico 155, 00161, Rome, Italy
| | - Silvia Santagata
- Department of Experimental Medicine, SAPIENZA University of Rome, Viale del Policlinico 155, 00161, Rome, Italy
| | - Giulia Valentini
- Department of Pediatrics, Child Neurology and Psychiatry, SAPIENZA University of Rome, Via dei Sabelli 108, 00185, Rome, Italy
| | - Antonio Angeloni
- Department of Experimental Medicine, SAPIENZA University of Rome, Viale del Policlinico 155, 00161, Rome, Italy
| | - Nenad Blau
- Dietmar-Hopp-Metabolic Center, University Children's Hospital, Heidelberg, Germany
| | - Vincenzo Leuzzi
- Department of Pediatrics, Child Neurology and Psychiatry, SAPIENZA University of Rome, Via dei Sabelli 108, 00185, Rome, Italy.
| |
Collapse
|
50
|
Romani C, MacDonald A, De Felice S, Palermo L. Speed of processing and executive functions in adults with phenylketonuria: Quick in finding the word, but not the ladybird. Cogn Neuropsychol 2017. [PMID: 28632427 DOI: 10.1080/02643294.2017.1320278] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
A reduction in processing speed is widely reported in phenylketonuria (PKU), possibly due to white matter pathology. We investigated possible deficits and their relationships with executive functions in a sample of 37 early-treated adults with PKU (AwPKUs). AwPKUs were not characterized by a generalized speed deficit, but instead their performance could be explained by two more specific impairments: (a) a deficit in the allocation of visuo-spatial attention that reduced speed in visual search tasks, in some reading conditions and visuo-motor coordination tasks; and (b) a more conservative decision mechanism that slowed down returning an answer across domains. These results suggest that the impairments in executive functions seen in AwPKUs are not the consequence of a generalized speed deficit. They also suggest that processing speed is linked to the efficiency of a particular cognitive component and cannot be considered a general function spanning domains. Similarities with patterns in ageing are discussed.
Collapse
Affiliation(s)
- Cristina Romani
- a School of Life and Health Sciences , Aston University , Birmingham , UK
| | | | - Sara De Felice
- a School of Life and Health Sciences , Aston University , Birmingham , UK
| | - Liana Palermo
- a School of Life and Health Sciences , Aston University , Birmingham , UK.,c Queen Elizabeth Hospital , Birmingham , UK.,d Department of Medical and Surgical Sciences , Magna Graecia University of Catanzaro , Catanzaro , Italy
| |
Collapse
|