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1.
J Inherit Metab Dis ; 42(3): 398-406, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30706953

RESUMO

Biogenic amines synthesis in phenylketonuria (PKU) patients with high phenylalanine (Phe) concentration is thought to be impaired due to inhibition of tyrosine and tryptophan hydroxylases and competition with amino acids at the blood-brain barrier. Dopamine and serotonin deficits might explain brain damage and progressive neuropsychiatric impairment in adult PKU patients. Ten early treated adult PKU patients (mean age 38.2 years) and 15 age-matched controls entered the study. Plasma and cerebrospinal fluid (CSF) Phe, 5-hydroxyindoleacetic acid (5-HIAA), 5-hydroxytryptophan (5-HTP), 3,4-dihydroxy-l-phenylalanine (l-DOPA) and homovanillic acid (HVA) were analyzed. Voxel-based morphometry statistical nonparametric mapping was used to test the age-corrected correlation between gray matter atrophy and CSF biogenic amines levels. 5-HIAA and 5-HTP were significantly reduced in PKU patients compared to controls. Significant negative correlations were found between CSF 5-HIAA, HVA, and 5-HTP and Phe levels. A decrease in 5-HIAA and 5-HTP concentrations correlated with precuneus and frontal atrophy, respectively. Lower HVA levels correlated with occipital atrophy. Biogenic amines deficits correlate with specific brain atrophy patterns in adult PKU patients, in line with serotonin and dopamine projections. These findings may support a more rigorous Phe control in adult PKU to prevent neurotransmitter depletion and accelerated brain damage due to aging.

2.
Genet Med ; 21(3): 580-590, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-29997390

RESUMO

PURPOSE: The nature of phenylalanine hydroxylase (PAH) variants determines residual enzyme activity, which modifies the clinical phenotype in phenylketonuria (PKU). We exploited the statistical power of a large genotype database to determine the relationship between genotype and phenotype in PKU. METHODS: A total of 9336 PKU patients with 2589 different genotypes, carrying 588 variants, were investigated using an allelic phenotype value (APV) algorithm. RESULTS: We identified 251 0-variants encoding inactive PAH, and assigned APVs (0 = classic PKU; 5 = mild PKU; 10 = mild hyperphenylalaninaemia) to 88 variants in PAH-functional hemizygous patients. The genotypic phenotype values (GPVs) were set equal to the higher-APV allele, which was assumed to be dominant over the lower-APV allele and to determine the metabolic phenotype. GPVs for 8872 patients resulted in cut-off ranges of 0.0-2.7 for classic PKU, 2.8-6.6 for mild PKU and 6.7-10.0 for mild hyperphenylalaninaemia. Genotype-based phenotype prediction was 99.2% for classic PKU, 46.2% for mild PKU and 89.5% for mild hyperphenylalaninaemia. The relationships between known pretreatment blood phenylalanine levels and GPVs (n = 4217), as well as tetrahydrobiopterin responsiveness and GPVs (n = 3488), were significant (both P < 0.001). CONCLUSIONS: APV and GPV are powerful tools to investigate genotype-phenotype associations, and can be used for genetic counselling of PKU families.


Assuntos
Estudos de Associação Genética/métodos , Fenilalanina Hidroxilase/genética , Fenilcetonúrias/genética , Alelos , Feminino , Frequência do Gene/genética , Genótipo , Humanos , Masculino , Mutação , Fenótipo , Fenilalanina Hidroxilase/fisiologia , Fenilcetonúrias/diagnóstico
3.
Am J Hum Genet ; 100(2): 257-266, 2017 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-28132689

RESUMO

Phenylketonuria (PKU, phenylalanine hydroxylase deficiency), an inborn error of metabolism, can be detected through newborn screening for hyperphenylalaninemia (HPA). Most individuals with HPA harbor mutations in the gene encoding phenylalanine hydroxylase (PAH), and a small proportion (2%) exhibit tetrahydrobiopterin (BH4) deficiency with additional neurotransmitter (dopamine and serotonin) deficiency. Here we report six individuals from four unrelated families with HPA who exhibited progressive neurodevelopmental delay, dystonia, and a unique profile of neurotransmitter deficiencies without mutations in PAH or BH4 metabolism disorder-related genes. In these six affected individuals, whole-exome sequencing (WES) identified biallelic mutations in DNAJC12, which encodes a heat shock co-chaperone family member that interacts with phenylalanine, tyrosine, and tryptophan hydroxylases catalyzing the BH4-activated conversion of phenylalanine into tyrosine, tyrosine into L-dopa (the precursor of dopamine), and tryptophan into 5-hydroxytryptophan (the precursor of serotonin), respectively. DNAJC12 was undetectable in fibroblasts from the individuals with null mutations. PAH enzyme activity was reduced in the presence of DNAJC12 mutations. Early treatment with BH4 and/or neurotransmitter precursors had dramatic beneficial effects and resulted in the prevention of neurodevelopmental delay in the one individual treated before symptom onset. Thus, DNAJC12 deficiency is a preventable and treatable cause of intellectual disability that should be considered in the early differential diagnosis when screening results are positive for HPA. Sequencing of DNAJC12 may resolve any uncertainty and should be considered in all children with unresolved HPA.


Assuntos
Distonia/genética , Deficiência Intelectual/genética , Fenilcetonúrias/genética , Proteínas Repressoras/genética , Alelos , Sequência de Aminoácidos , Biopterina/análogos & derivados , Biopterina/metabolismo , Estudos de Casos e Controles , Dopamina/deficiência , Dopamina/metabolismo , Éxons , Feminino , Fibroblastos/metabolismo , Deleção de Genes , Estudo de Associação Genômica Ampla , Proteínas de Choque Térmico HSP70/genética , Humanos , Masculino , Linhagem , Fenilalanina/metabolismo , Fenilalanina Hidroxilase/genética , Serotonina/deficiência , Serotonina/metabolismo , Triptofano/metabolismo , Triptofano Hidroxilase/genética , Triptofano Hidroxilase/metabolismo , Tirosina/metabolismo , Tirosina 3-Mono-Oxigenase/genética , Tirosina 3-Mono-Oxigenase/metabolismo
4.
Mol Genet Metab Rep ; 6: 55-9, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27014578

RESUMO

Cobalamin C (cblC) defect is an inherited autosomal recessive disorder that affects cobalamin metabolism. Patients are treated with hydroxycobalamin to ameliorate the clinical features of early-onset disease and prevent clinical symptoms in late-onset disease. Here we describe a patient in whom prenatal maternal treatment with 30 mg/week hydroxycobalamin and 5 mg/day folic acid from week 15 of pregnancy prevented disease manifestation in a girl who is now 11 years old with normal IQ and only mild ophthalmic findings. The affected older sister received postnatal treatment only and is severely intellectually disabled with severe ophthalmic symptoms. This case highlights the potential of early, high-dose intrauterine treatment in a fetus affected by the cblC defect.

5.
Eur J Pediatr ; 175(2): 261-72, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26350228

RESUMO

UNLABELLED: To avoid potentially severe outcomes, phenylketonuria (PKU) must be detected as soon as possible after birth and managed with life-long treatment. A questionnaire-based survey was performed to document diagnosis and management practices for PKU in a region of Southern and Eastern Europe. Prevalence and management data were obtained from 37/59 (63 %) centres within 19/22 (86%) contacted countries (N = 8600 patients). The main results' analysis was based on completed questionnaires obtained from 31 centres (53%) within 15 countries (68%). A median of 10 % of patients per centre had been diagnosed after the newborn period. Metabolic dieticians and specialised adult PKU clinics were lacking in 36 and 84% of centres, respectively. In 26% of centres, treatment initiation was delayed until >15 days of life. Blood phenylalanine (Phe) thresholds to start treatment and upper Phe targets were inconsistent across centres. Ten percent of centres reported monitoring Phe every 2 weeks for pregnant women with PKU, which is insufficient to minimise risk of neonatal sequalae. Sapropterin dihydrochloride treatment was available in 48% of centres, with 24-h responsiveness tests most common (36%). Only one centre among the five countries lacking newborn screening provided a completed questionnaire. CONCLUSION: Targeted efforts by health care professionals and governments are needed to optimise diagnostic and management approaches for PKU in Southern and Eastern Europe. WHAT IS KNOWN: PKU must be detected early and optimally managed throughout life to avoid poor outcomes, yet newborn screening is not universal and diagnostic and management practices for PKU are known to vary widely between different centres and countries. Targeted efforts by health care professionals and governments are needed to optimise diagnostic and management approaches. WHAT IS NEW: PKU management practices are documented in 19 South and Eastern European countries indicating a heterogeneous situation across the region. Key areas for improvement identified in surveyed centres include a need for comprehensive screening in all countries, increased number of metabolic dietitians and specialised adult PKU clinics, delayed time to treatment initiation, appropriate Phe thresholds, Phe targets and monitoring frequencies, and universal access to currently available treatment options.


Assuntos
Triagem Neonatal/métodos , Fenilalanina/sangue , Fenilcetonúrias/diagnóstico , Adolescente , Adulto , Criança , Pré-Escolar , Gerenciamento Clínico , Europa (Continente) , Feminino , Pessoal de Saúde , Humanos , Lactente , Recém-Nascido , Fenilcetonúrias/epidemiologia , Fenilcetonúrias/terapia , Gravidez , Inquéritos e Questionários , Adulto Jovem
6.
J Inherit Metab Dis ; 39(1): 115-24, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26025547

RESUMO

BACKGROUND: Severe methylenetetrahydrofolate reductase (MTHFR) deficiency is a rare inborn defect disturbing the remethylation of homocysteine to methionine (<200 reported cases). This retrospective study evaluates clinical, biochemical genetic and in vitro enzymatic data in a cohort of 33 patients. METHODS: Clinical, biochemical and treatment data was obtained from physicians by using a questionnaire. MTHFR activity was measured in primary fibroblasts; genomic DNA was extracted from cultured fibroblasts. RESULTS: Thirty-three patients (mean age at follow-up 11.4 years; four deceased; median age at first presentation 5 weeks; 17 females) were included. Patients with very low (<1.5%) mean control values of enzyme activity (n = 14) presented earlier and with a pattern of feeding problems, encephalopathy, muscular hypotonia, neurocognitive impairment, apnoea, hydrocephalus, microcephaly and epilepsy. Patients with higher (>1.7-34.8%) residual enzyme activity had mainly psychiatric symptoms, mental retardation, myelopathy, ataxia and spasticity. Treatment with various combinations of betaine, methionine, folate and cobalamin improved the biochemical and clinical phenotype. During the disease course, patients with very low enzyme activity showed a progression of feeding problems, neurological symptoms, mental retardation, and psychiatric disease while in patients with higher residual enzyme activity, myelopathy, ataxia and spasticity increased. All other symptoms remained stable or improved in both groups upon treatment as did brain imaging in some cases. No clear genotype-phenotype correlation was obvious. DISCUSSION: MTHFR deficiency is a severe disease primarily affecting the central nervous system. Age at presentation and clinical pattern are correlated with residual enzyme activity. Treatment alleviates biochemical abnormalities and clinical symptoms partially.


Assuntos
Homocistinúria/enzimologia , Homocistinúria/genética , Metilenotetra-Hidrofolato Redutase (NADPH2)/deficiência , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Espasticidade Muscular/enzimologia , Espasticidade Muscular/genética , Ataxia/genética , Betaína/uso terapêutico , Criança , Feminino , Ácido Fólico/uso terapêutico , Estudos de Associação Genética/métodos , Homocistinúria/tratamento farmacológico , Humanos , Deficiência Intelectual/genética , Masculino , Metionina/uso terapêutico , Espasticidade Muscular/tratamento farmacológico , Mutação/genética , Fenótipo , Transtornos Psicóticos/tratamento farmacológico , Transtornos Psicóticos/enzimologia , Transtornos Psicóticos/genética , Estudos Retrospectivos , Doenças da Medula Espinal/genética , Vitamina B 12/uso terapêutico
7.
Mol Genet Metab ; 114(4): 564-9, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25726095

RESUMO

Neonatal loading studies with tetrahydrobiopterin (BH4) are used to detect hyperphenylalaninemia due to BH4 deficiency by evaluating decreases in blood phenylalanine (Phe) concentrations post BH4 load. BH4 responsiveness in phenylalanine hydroxylase (PAH)-deficient patients introduced a new diagnostic aspect for this test. In older children, a broad spectrum of different levels of responsiveness has been described. The primary objective of this study was to develop a pharmacodynamic model to improve the description of individual sensitivity to BH4 in the neonatal period. Secondary objectives were to evaluate BH4 responsiveness in a large number of PAH-deficient patients from a neonatal screening program and in patients with various confirmed BH4 deficiencies from the BIODEF database. Descriptive statistics in patients with PAH deficiency with 0-24-h data available showed that 129 of 340 patients (37.9%) had a >30% decrease in Phe levels post load. Patients with dihydropteridine reductase deficiency (n = 53) could not be differentiated from BH4-responsive patients with PAH deficiency. The pharmacologic turnover model, "stimulation of loss" of Phe following BH4 load, fitted the data best. Using the model, 193 of 194 (99.5%) patients with a proven BH4 synthesis deficiency or recycling defect were classified as BH4 sensitive. Among patients with PAH deficiency, 216 of 375 (57.6%) patients showed sensitivity to BH4, albeit with a pronounced variability; PAH-deficient patients with blood Phe <1200 µmol/L at time 0 showed higher sensitivity than patients with blood Phe levels >1200 µmol/L. External validation showed good correlation between the present approach, using 0-24-h blood Phe data, and the published 48-h prognostic test. Pharmacodynamic modeling of Phe levels following a BH4 loading test is sufficiently powerful to detect a wide range of responsiveness, interpretable as a measure of sensitivity to BH4. However, the clinical relevance of small responses needs to be evaluated by further studies of their relationship to long-term response to BH4 treatment.


Assuntos
Biopterina/análogos & derivados , Fenilalanina/farmacocinética , Biopterina/administração & dosagem , Biopterina/deficiência , Biopterina/farmacologia , Biopterina/uso terapêutico , Feminino , Humanos , Recém-Nascido , Masculino , Modelos Estatísticos , Triagem Neonatal , Fenilalanina/sangue , Fenilalanina Hidroxilase/deficiência , Fenilcetonúrias/sangue , Fenilcetonúrias/diagnóstico , Fenilcetonúrias/tratamento farmacológico , Fenilcetonúrias/metabolismo , Prognóstico , Estudos Retrospectivos
8.
JIMD Rep ; 23: 35-43, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25822821

RESUMO

INTRODUCTION: Sapropterin dihydrochloride (Kuvan(®)), a synthetic 6R-diastereoisomer of tetrahydrobiopterin (BH4), is approved in Europe for the treatment of patients aged ≥4 years with hyperphenylalaninaemia (HPA) due to BH4-responsive phenylalanine hydroxylase (PAH) deficiency, in conjunction with a phenylalanine-restricted diet, and also for the treatment of patients with BH4 deficiency. AIMS/METHODS: KAMPER is an ongoing, observational, multicentre registry with the primary objective of providing information over 15 years on long-term safety of sapropterin dihydrochloride treatment in patients with HPA. Here we report initial data on characteristics from patients recruited by the time of the third interim analysis and results at 1 year. RESULTS: Overall, 325 patients from 55 sites in seven European countries were included in the analysis: 296 (91.1%) patients with PAH deficiency (median [Q1, Q3] age, 10.3 [7.2, 15.0] years) and 29 (8.9%) with BH4 deficiency (12.8 [6.6, 18.9] years). Fifty-nine patients (18.2%) were aged ≥18 years; 4 patients were pregnant. No elderly patients (aged ≥65 years) or patients with renal or hepatic insufficiency were enroled in the study. Twelve-month data were available for 164 patients with PAH deficiency and 16 with BH4 deficiency. No new safety concerns were identified as of May 2013. CONCLUSIONS: Initial data from KAMPER show that sapropterin dihydrochloride has a favourable safety profile. Registry data collected over time will provide insight into the management and outcomes of patients with PAH deficiency and BH4 deficiency, including long-term safety, impact on growth and neurocognitive outcomes and the effect of sapropterin dihydrochloride treatment on populations of special interest.

9.
Eur J Pediatr ; 174(1): 119-27, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25480112

RESUMO

UNLABELLED: Phenylketonuria (PKU) is no longer considered merely a pediatric concern; current guidelines recommend life-long treatment. However, information on the adult PKU patient population is scarce. A survey was initiated on behalf of the European PKU Group (EPG) that focused specifically on early-treated adult patients diagnosed by neonatal screening. The online survey was sent via email to 204 healthcare professionals (HCPs) in 33 countries. Eighty-one HCPs from 24 countries responded. The main findings were that the majority of adult patients with PKU in active follow-up are under 30 years of age and are managed in centers that also treat children. Seventy-eight percent of adult PKU patients in follow-up receive treatment, mainly by diet (71 %), with BH4 treatment rarely used in adulthood. Only 26 % of responding HCPs perform routine neurocognitive testing in all their adult patients. There was little consensus regarding target blood phenylalanine (Phe) concentrations, although the majority of respondents reported that their patients achieved blood Phe concentrations below 1200 µmol/l. CONCLUSION: This survey highlights the need for blood Phe concentration target recommendations and consensus guidelines, more research into adult PKU patient management, and the need to identify those patients lost to follow-up to ensure PKU is managed for life.


Assuntos
Fenilcetonúrias/terapia , Padrões de Prática Médica , Adulto , Pesquisas sobre Serviços de Saúde , Pessoal de Saúde , Humanos , Fenilalanina/sangue , Fenilcetonúrias/sangue , Inquéritos e Questionários
10.
J Inherit Metab Dis ; 37(5): 831-40, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24599607

RESUMO

UNLABELLED: The cblC defect is the most common inborn error of vitamin B12 metabolism. Despite therapeutic measures, the long-term outcome is often unsatisfactory. This retrospective multicentre study evaluates clinical, biochemical and genetic findings in 88 cblC patients. The questionnaire designed for the study evaluates clinical and biochemical features at both initial presentation and during follow up. Also the development of severity scores allows investigation of individual disease load, statistical evaluation of parameters between the different age of presentation groups, as well as a search for correlations between clinical endpoints and potential modifying factors. RESULTS: No major differences were found between neonatal and early onset patients so that these groups were combined as an infantile-onset group representing 88 % of all cases. Hypotonia, lethargy, feeding problems and developmental delay were predominant in this group, while late-onset patients frequently presented with psychiatric/behaviour problems and myelopathy. Plasma total homocysteine was higher and methionine lower in infantile-onset patients. Plasma methionine levels correlated with "overall impression" as judged by treating physicians. Physician's impression of patient's well-being correlated with assessed disease load. We confirmed the association between homozygosity for the c.271dupA mutation and infantile-onset but not between homozygosity for c.394C>T and late-onset. Patients were treated with parenteral hydroxocobalamin, betaine, folate/folinic acid and carnitine resulting in improvement of biochemical abnormalities, non-neurological signs and mortality. However the long-term neurological and ophthalmological outcome is not significantly influenced. In summary the survey points to the need for prospective studies in a large cohort using agreed treatment modalities and monitoring criteria.


Assuntos
Erros Inatos do Metabolismo/genética , Erros Inatos do Metabolismo/metabolismo , Proteínas Proto-Oncogênicas c-cbl/genética , Vitamina B 12/metabolismo , Idade de Início , Encéfalo/patologia , Proteínas de Transporte/genética , Criança , Pré-Escolar , Progressão da Doença , Grupos Étnicos , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Erros Inatos do Metabolismo/terapia , Oxirredutases , Prognóstico , Inquéritos e Questionários
11.
Mol Genet Metab ; 110(4): 418-23, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24090706

RESUMO

Fluctuations in blood phenylalanine concentrations may be an important determinant of intellectual outcome in patients with early and continuously treated phenylketonuria (PKU). This review evaluates the studies on phenylalanine fluctuations, factors affecting fluctuations, and if stabilizing phenylalanine concentrations affects outcomes, particularly neurocognitive outcome. Electronic literature searches of Embase and PubMed were performed for English-language publications, and the bibliographies of identified publications were also searched. In patients with PKU, phenylalanine concentrations are highest in the morning. Factors that can affect phenylalanine fluctuations include age, diet, timing and dosing of protein substitute and energy intake, dietary adherence, phenylalanine hydroxylase genotype, changes in dietary phenylalanine intake and protein metabolism, illness, and growth rate. Even distribution of phenylalanine-free protein substitute intake throughout 24h may reduce blood phenylalanine fluctuations. Patients responsive to and treated with 6R-tetrahydrobiopterin seem to have less fluctuation in their blood phenylalanine concentrations than controls. An increase in blood phenylalanine concentration may result in increased brain and cerebrospinal fluid phenylalanine concentrations within hours. Although some evidence suggests that stabilization of blood phenylalanine concentrations may have benefits in patients with PKU, more studies are needed to distinguish the effects of blood phenylalanine fluctuations from those of poor metabolic control.


Assuntos
Biopterina/análogos & derivados , Fenilalanina/sangue , Fenilalanina/genética , Fenilcetonúrias/sangue , Adulto , Fatores Etários , Biopterina/uso terapêutico , Dieta , Humanos , Fenilalanina/metabolismo , Fenilalanina Hidroxilase/genética , Fenilalanina Hidroxilase/metabolismo , Fenilcetonúrias/tratamento farmacológico , Fenilcetonúrias/genética , Fenilcetonúrias/fisiopatologia , PubMed
12.
Mol Genet Metab ; 110 Suppl: S18-24, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24055312

RESUMO

Dietary treatment may be associated with an increased risk of obesity in phenylketonuria (PKU). The earliest studies describe a tendency for overweight in PKU, but not all recent publications confirm this, although there are an increasing number of studies describing increased obesity in female patients with PKU. There is little data describing the metabolic consequences of obesity in PKU. It is difficult to interpret and compare published results due to variable patient age, differing dietary treatment approaches, poor treatment adherence, inconsistencies in metabolic control achieved, variable criteria used to classify overweight. There is also a lack of comparison with normal population data which is widely variable between countries. Generally in PKU it is unknown if obesity etiology is a result of the underlying condition, a treatment consequence, or an outcome of inadequate metabolic control. Differences in treatment strategies, target ranges for blood phenylalanine concentrations and severity of PKU can alter nutritional intakes and dietary experiences which ultimately modulate the course of overweight development. It is clear further investigation is required. Treating overweight and obesity in the general population is difficult and no studies have described the impact of obesity treatment strategies in PKU. However, the PKU management team has an important role in monitoring nutritional status and preventing overweight and obesity. It is important that PKU treatment attends to the general aspects of nutrition, feeding behavior and exercise in order to prevent the development of overweight in these individuals.


Assuntos
Comportamento Alimentar , Obesidade/etiologia , Fenilcetonúrias/complicações , Exercício , Feminino , Humanos , Masculino , Estado Nutricional , Obesidade/prevenção & controle , Cooperação do Paciente , Fenilalanina/sangue , Fenilcetonúrias/sangue , Fenilcetonúrias/dietoterapia , Prevalência , Fatores de Risco
13.
Orphanet J Rare Dis ; 6: 44, 2011 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-21689452

RESUMO

BACKGROUND: National newborn screening programmes based on tandem-mass spectrometry (MS/MS) and other newborn screening (NBS) technologies show a substantial variation in number and types of disorders included in the screening panel. Once established, these methods offer the opportunity to extend newborn screening panels without significant investment and cost. However, systematic evaluations of newborn screening programmes are rare, most often only describing parts of the whole process from taking blood samples to long-term evaluation of outcome. METHODS: In a prospective single screening centre observational study 373 cases with confirmed diagnosis of a metabolic disorder from a total cohort of 1,084,195 neonates screened in one newborn screening laboratory between January 1, 1999, and June 30, 2009 and subsequently treated and monitored in five specialised centres for inborn errors of metabolism were examined. Process times for taking screening samples, obtaining results, initiating diagnostic confirmation and starting treatment as well as the outcome variables metabolic decompensations, clinical status, and intellectual development at a mean age of 3.3 years were evaluated. RESULTS: Optimal outcome is achieved especially for the large subgroup of patients with medium-chain acyl-CoA dehydrogenase deficiency. Kaplan-Meier-analysis revealed disorder related patterns of decompensation. Urea cycle disorders, organic acid disorders, and amino acid disorders show an early high and continuous risk, medium-chain acyl-CoA dehydrogenase deficiency a continuous but much lower risk for decompensation, other fatty acid oxidation disorders an intermediate risk increasing towards the end of the first year. Clinical symptoms seem inevitable in a small subgroup of patients with very early disease onset. Later decompensation can not be completely prevented despite pre-symptomatic start of treatment. Metabolic decompensation does not necessarily result in impairment of intellectual development, but there is a definite association between the two. CONCLUSIONS: Physical and cognitive outcome in patients with presymptomatic diagnosis of metabolic disorders included in the current German screening panel is equally good as in phenylketonuria, used as a gold standard for NBS. Extended NBS entails many different interrelated variables which need to be carefully evaluated and optimized. More reports from different parts of the world are needed to allow a comprehensive assessment of the likely benefits, harms and costs in different populations.


Assuntos
Doenças do Recém-Nascido/diagnóstico , Erros Inatos do Metabolismo/diagnóstico , Triagem Neonatal/métodos , Avaliação da Tecnologia Biomédica , Feminino , Alemanha/epidemiologia , Humanos , Recém-Nascido , Doenças do Recém-Nascido/epidemiologia , Masculino , Erros Inatos do Metabolismo/epidemiologia , Fenilcetonúrias/diagnóstico , Fenilcetonúrias/epidemiologia , Espectrometria de Massas em Tandem/métodos
14.
Mol Genet Metab ; 103(4): 315-22, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21646032

RESUMO

BACKGROUND: Phenylketonuria (PKU) results from impaired breakdown of phenylalanine (Phe) due to deficient phenylalanine hydroxylase (PAH) activity. Sapropterin dihydrochloride (sapropterin, Kuvan®) is the only US- and EU-approved pharmaceutical version of naturally occurring 6R-BH(4), the cofactor required for PAH activity. Sapropterin enhances residual PAH activity in sapropterin-responsive PKU patients and, in conjunction with dietary management, helps reduce blood Phe concentrations for optimal control. Approval was based on the positive safety and efficacy results of four international clinical studies, the longest of which was 22 weeks in duration. OBJECTIVE: To evaluate the safety of long-term treatment with sapropterin in PKU subjects who participated in previous Phase 3 sapropterin trials. METHODS: PKU-008 was designed as a Phase 3b, multicenter, multinational, open-label, 3-year extension trial to evaluate the long-term safety of sapropterin in patients with PKU who were classified as sapropterin responders and participated in prior Phase 3 sapropterin studies: 111 subjects aged 4-50 years completed prior studies and were subsequently enrolled in study PKU-008. Routine safety monitoring was performed at 3-month intervals and included adverse event reporting, blood Phe monitoring, clinical laboratory evaluations, physical examinations and vital sign measurements. RESULTS: Average exposure during PKU-008 was 658.7±221.3 days (range, 56-953; median, 595). The average total duration of participation in multiple studies (PKU-001, PKU-003, PKU-004, and PKU-008; or PKU-006 and PKU-008) was 799.0±237.5 days (range, 135-1151). The mean sapropterin dose was 16.2±4.7 mg/kg/day. Most adverse events were considered unrelated to treatment, were mild or moderate in severity, and were consistent with prior studies of sapropterin. No age-specific differences were observed in adverse event reporting. Three subjects discontinued treatment due to adverse events that were considered possibly or probably related to study treatment (one each of difficulty concentrating, decreased platelet count, and intermittent diarrhea). No deaths were reported. Of seven reported serious adverse events, one was considered possibly related to study treatment (gastroesophageal reflux). There were no laboratory or physical examination abnormalities requiring medical interventions. For most subjects, blood Phe concentrations were consistently within target range, confirming the durability of response in subjects undergoing extended treatment with sapropterin. CONCLUSION: Sapropterin treatment was found to be safe and well tolerated at doses of 5 to 20mg/kg/day for an average exposure of 659 days. This study supports the safety and tolerability of sapropterin as long-term treatment for patients with PKU.


Assuntos
Biopterina/análogos & derivados , Fenilcetonúrias/tratamento farmacológico , Adolescente , Adulto , Biopterina/efeitos adversos , Criança , Pré-Escolar , Relação Dose-Resposta a Droga , Feminino , Humanos , Pessoa de Meia-Idade , Fenilalanina/sangue
15.
Pediatrics ; 126(2): 333-41, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20624808

RESUMO

Despite recent advances in the management of phenylketonuria and hyperphenylalaninemia, important questions on the management of this disorder remain unanswered. Consensus exists on the need for neonatal screening and early treatment, yet disagreement persists over threshold levels of blood phenylalanine for starting treatment, target blood phenylalanine levels, and the management of older patient groups. The mainstay of treatment is a phenylalanine-restricted diet, but its application varies between and within countries. Beyond diet treatment, there is a lack of consensus on the use of newer treatments such as tetrahydrobiopterin. Although neonatal screening and early treatment has meant that most well-treated children grow up with near-normal IQ scores, the effect of relaxing metabolic control on cognitive and executive function later in life is still not fully understood. Although it is clear from the available literature that the active control of blood phenylalanine levels is of vital importance, there are other treatment-related factors that affect outcome. A uniform and firmly evidence-based approach to the management of phenylketonuria is required.


Assuntos
Fenilcetonúrias/tratamento farmacológico , Biopterina/análogos & derivados , Biopterina/uso terapêutico , Encéfalo/metabolismo , Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/epidemiologia , Consenso , Transtornos do Crescimento/sangue , Transtornos do Crescimento/epidemiologia , Humanos , Recém-Nascido , Triagem Neonatal , Testes Neuropsicológicos , Fenilalanina/sangue , Fenilcetonúrias/sangue , Fenilcetonúrias/epidemiologia , Falha de Tratamento
16.
J Inherit Metab Dis ; 33 Suppl 3: S163-9, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20217238

RESUMO

Treatment with tetrahydrobiopterin (BH4), the natural cofactor of phenylalanine hydroxylase (PAH), can reduce blood phenylalanine (Phe) levels in patients with BH4-responsive phenylketonuria (PKU). A number of studies has reported on the short-term BH4 treatment of patients with PKU, but long-term data are lacking. Here, we describe the effects of long-term treatment with BH4 on 16 patients, who showed a >28% reduction in blood Phe following testing for BH4 overload. The mean dose of BH4 was 16 mg/kg body weight (range 5-36 mg/kg body weight). The mean treatment duration was 56 months (range 24-110 months). Of 16 patients, 14 achieved long-term Phe control with BH4 treatment, with a mean blood Phe concentration of 321 ± 236 µmol/l. The mean decrease from baseline in blood Phe levels in these 14 patients was 54.6%. Of the seven patients who required continued dietary restriction, Phe intake increased from 200-300 mg/day to 800-1000 mg/day. Factors that may cause fluctuation of Phe levels in BH4-treated patients include patients' PAH genotype, Phe intake, changes in protein catabolism or anabolism, and periods of illness or infection.


Assuntos
Biopterina/análogos & derivados , Fenilcetonúrias/tratamento farmacológico , Adolescente , Biomarcadores/sangue , Biopterina/administração & dosagem , Biopterina/uso terapêutico , Peso Corporal , Criança , Pré-Escolar , Terapia Combinada , Dieta com Restrição de Proteínas , Cálculos da Dosagem de Medicamento , Seguimentos , Humanos , Lactente , Recém-Nascido , Fenilalanina/sangue , Fenilcetonúrias/sangue , Fenilcetonúrias/diagnóstico , Fenilcetonúrias/dietoterapia , Fatores de Tempo , Resultado do Tratamento
17.
Mol Genet Metab ; 99 Suppl 1: S68-74, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20123474

RESUMO

Elevated phenylalanine (Phe) levels in pregnant women with PKU are teratogenic. Fetal damage due to elevated maternal Phe levels during pregnancy is known as maternal phenylketonuria (MPKU). The risk of birth defects in MPKU, including global developmental delays, microcephaly, congenital heart disease, and low birth weight, can be dramatically reduced by controlling Phe levels during pregnancy (metabolic control). Phe levels should be maintained in the range of 120-360 micromol/L, ideally starting before pregnancy begins (i.e., when planning a pregnancy). If control is not achieved before pregnancy (e.g., if the pregnancy was unplanned), good outcomes are still possible if metabolic control is established by 8 weeks of pregnancy. Unfortunately, metabolic control before and during pregnancy can be poor. As well, many mothers stop treatment after pregnancy, which can decrease the mother's ability to focus on her child and increase her risk of behavioral and psychological problems. This can have a negative effect on the home environment. Many factors affect adherence to the strict diet used to control Phe levels, including poor access to medical care, lack of reimbursement for medical foods (in some regions, such as parts of the United States), practical difficulties with implementing the diet, financial constraints, demographics, and psychosocial issues. A comprehensive treatment approach that begins prior to pregnancy and continues after the infant is born may help to improve the management of MPKU. This approach should include education of girls about MPKU at an early age, interventions to prevent unplanned pregnancies, psychosocial support, improved treatment access and reimbursement for medical foods, and treatment guidelines. Treatments such as sapropterin may also have a role in improving metabolic control during pregnancy.


Assuntos
Fenilcetonúrias/fisiopatologia , Fenilcetonúrias/psicologia , Complicações na Gravidez/fisiopatologia , Complicações na Gravidez/psicologia , Feminino , Humanos , Fenilcetonúrias/metabolismo , Gravidez , Complicações na Gravidez/metabolismo , Primeiro Trimestre da Gravidez , Tirosina/administração & dosagem
18.
Hum Mutat ; 31(4): 380-90, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20052767

RESUMO

L-2-Hydroxyglutaric aciduria (L2HGA) is a rare, neurometabolic disorder with an autosomal recessive mode of inheritance. Affected individuals only have neurological manifestations, including psychomotor retardation, cerebellar ataxia, and more variably macrocephaly, or epilepsy. The diagnosis of L2HGA can be made based on magnetic resonance imaging (MRI), biochemical analysis, and mutational analysis of L2HGDH. About 200 patients with elevated concentrations of 2-hydroxyglutarate (2HG) in the urine were referred for chiral determination of 2HG and L2HGDH mutational analysis. All patients with increased L2HG (n=106; 83 families) were included. Clinical information on 61 patients was obtained via questionnaires. In 82 families the mutations were detected by direct sequence analysis and/or multiplex ligation dependent probe amplification (MLPA), including one case where MLPA was essential to detect the second allele. In another case RT-PCR followed by deep intronic sequencing was needed to detect the mutation. Thirty-five novel mutations as well as 35 reported mutations and 14 nondisease-related variants are reviewed and included in a novel Leiden Open source Variation Database (LOVD) for L2HGDH variants (http://www.LOVD.nl/L2HGDH). Every user can access the database and submit variants/patients. Furthermore, we report on the phenotype, including neurological manifestations and urinary levels of L2HG, and we evaluate the phenotype-genotype relationship.


Assuntos
Oxirredutases do Álcool/genética , Encefalopatias Metabólicas Congênitas/enzimologia , Encefalopatias Metabólicas Congênitas/genética , Estudos de Associação Genética , Mutação/genética , Animais , Encefalopatias Metabólicas Congênitas/patologia , Modelos Animais de Doenças , Humanos
19.
Mol Genet Metab ; 99(2): 109-15, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19800826

RESUMO

To gain better insight in the most current diagnosis and treatment practices for phenylketonuria (PKU) from a broad group of experts, a European PKU survey was performed. The questionnaire, consisting of 33 questions, was sent to 243 PKU professionals in 165 PKU centers in 23 European countries. The responses were compiled and descriptive analyses were performed. One hundred and one questionnaires were returned by 93/165 centers (56%) from 19/23 European countries (83%). The majority of respondents (77%) managed patients of all age groups and more than 90% of PKU teams included physicians or dieticians/nutritionists. The greatest variability existed especially in the definition of PKU phenotypes, therapeutic blood phenylalanine (Phe) target concentrations, and follow-up practices for PKU patients. The tetrahydrobiopterin (BH4; sapropterin) loading test was performed by 54% of respondents, of which 61% applied a single dose test (20mg/kg over 24h). BH4 was reported as a treatment option by 34%. This survey documents differences in diagnostic and treatment practices for PKU patients in European centers. In particular, recommendations for the treatment decision varied greatly between different European countries. There is an urgent need to pool long-term data in PKU registries in order to generate an evidence-based international guideline.


Assuntos
Pesquisas sobre Serviços de Saúde , Fenilcetonúrias/terapia , Adulto , Pré-Escolar , Europa (Continente) , Seguimentos , Diretrizes para o Planejamento em Saúde , Humanos , Recém-Nascido , Fenilalanina/sangue , Fenilcetonúrias/sangue , Fenilcetonúrias/diagnóstico , Sistema de Registros , Inquéritos e Questionários
20.
Hum Mutat ; 31(3): 279-83, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20020533

RESUMO

We performed molecular, enzyme, and metabolic studies in 50 patients with D-2-hydroxyglutaric aciduria (D-2-HGA) who accumulated D-2-hydroxyglutarate (D-2-HG) in physiological fluids. Presumed pathogenic mutations were detected in 24 of 50 patients in the D-2-hydroxyglutarate dehydrogenase (D2HGDH) gene, which encodes D-2-hydroxyglutarate dehydrogenase (D-2-HGDH). Enzyme assay of D-2-HGDH confirmed that all patients with mutations had impaired enzyme activity, whereas patients with D-2-HGA whose enzyme activity was normal did not have mutations. Significantly lower D-2-HG concentrations in body fluids were observed in mutation-positive D-2-HGA patients than in mutation-negative patients. These results imply that multiple genetic loci may be associated with hyperexcretion of D-2-HG. Accordingly, we suggest a new classification: D-2-HGA Type I associates with D-2-HGDH deficiency, whereas idiopathic D-2-HGA manifests with normal D-2-HGDH activity and higher D-2-HG levels in body fluids compared with Type I patients. It remains possible that several classifications for idiopathic D-2-HGA patients with diverse genetic loci will be revealed in future studies.


Assuntos
Oxirredutases do Álcool/genética , Glutaratos/sangue , Glutaratos/urina , Deficiência Múltipla de Acil Coenzima A Desidrogenase/genética , Algoritmos , Líquidos Corporais , Análise Mutacional de DNA , Genótipo , Glutaratos/líquido cefalorraquidiano , Homozigoto , Humanos , Modelos Genéticos , Mutação , Reprodutibilidade dos Testes , Ácido gama-Aminobutírico/análogos & derivados , Ácido gama-Aminobutírico/genética
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