Metabolic control and body composition of children and adolescents with phenylketonuria / Controle metabólico e composição corporal de crianças e adolescentes com diagnóstico neonatal de fenilcetonúria

ABSTRACT Objective: To characterize metabolic control and verify whether it has any relation with socioeconomic, demographic, and body composition variables in children and adolescents with phenylketonuria (PKU) diagnosed in the neonatal period. Methods: This cohort study collected retrospective data of 53 phenylketonuric children and adolescents. Data on family income, housing, and mother's age and schooling level were collected, and anthropometric measures of body composition and distribution were taken. All dosages of phenylalanine (Phe) from the last five years (2015-2019) were evaluated and classified regarding their adequacy (cutoffs: 0-12 years: 2-6 mg/dL; 12-19 years: 2-10 mg/dL). Adequate metabolic control was considered if ≥7%) of the dosages were within desired ranges. Results: The mean (±standard deviation) age in the last year was 10.1±4.6 years. Most of them were under 12 years old (33/53; 62.3%) and had the classic form of the disease (39/53; 73.6%). Better metabolic control was observed among adolescents (68.4 versus 51.4%; p=0.019). Overweight was found in 9/53 (17%) and higher serum Phe levels (p<0.001) were found in this group of patients. Metabolic control with 70% or more Phe level adequacy decreased along with the arm muscle area (AMA) (ptendency=0.042), being 70.0% among those with low reserve (low AMA), and 18.5% among those with excessive reserve (high AMA). Conclusions: Adequate metabolic control was observed in most patients. The findings suggest that, in this sample, the levels of phenylalanine may be related to changes in body composition.

RESUMO Objetivo: Caracterizar o controle metabólico e verificar se existe relação entre ele, variáveis socioeconômicas, demográficas e composição corporal de crianças e adolescentes com fenilcetonúria (FNC) diagnosticada no período neonatal. Métodos: Coorte com coleta retrospectiva de dados de 53 crianças e adolescentes fenilcetonúricos. Foram coletados dados de renda familiar, moradia, idade e escolaridade materna e realizaram-se medidas antropométricas de composição e distribuição corporal. Todas as dosagens de fenilalanina (Fal) dos últimos cinco anos (2015-2019) foram avaliadas e classificadas quanto à adequação (cortes: 0-12 anos: 2-6 mg/dL; 12-19 anos: 2-10 mg/dL). A proporção de dosagens adequadas ≥70% foi considerada como controle metabólico adequado. Resultados: A média (±desvio padrão) de idade, no último ano, foi de 10,1±4,6 anos. A maioria tinha menos de 12 anos (33/53; 62,3%) e apresentava a forma clássica da doença (39/53; 73,6%). Observou-se melhor controle metabólico entre os adolescentes (68,4 vs. 51,4%; p=0,019). Excesso de peso foi encontrado em 9/53 (17%) e maiores níveis séricos de Fal foram descritos nesse grupo (p<0,001). O percentual de controle metabólico com 70% ou mais de adequação dos níveis de Fal foi decrescente de acordo com a área muscular do braço (AMB; ptendência=0,042), sendo de 70% entre os de baixa reserva (AMB reduzida) e de 18,5% entre os com excesso (AMB elevada). Conclusões: Observou-se controle metabólico adequado na maioria dos avaliados e os achados sugerem que, nesta amostra, os níveis de fenilalanina podem estar relacionados com alterações da composição corporal.

Quality of life and adherence to treatment in early-treated Brazilian phenylketonuria pediatric patients

Early dietary treatment of phenylketonuria (PKU), an inborn error of phenylalanine (Phe) metabolism, results in normal cognitive development. Although health-related quality of life (HRQoL) of PKU patients has been reported as unaffected in high-income countries, there are scarce data concerning HRQoL and adherence to treatment of PKU children and adolescents from Brazil. The present study compared HRQoL scores in core dimensions of Brazilian early-treated PKU pediatric patients with those of a reference population, and explored possible relationships between adherence to treatment and HRQoL. Early-treated PKU pediatric patient HRQoL was evaluated by self- and parent-proxy reports of the Pediatric Quality of Life Inventory (PedsQL) core scales. Adherence to treatment was evaluated by median Phe levels and percentage of results within the therapeutic target range in two periods. Means for total and core scales scores of PedsQL self- and parent proxy-reports of PKU patients were significantly lower than their respective means for controls. Adequacy of median Phe concentrations and the mean percentage of values in the target range fell substantially from the first year of life to the last year of this study. There was no significant difference in mean total and core scale scores for self- and parent proxy-reports between patients with adequate and those with inadequate median Phe concentrations. The harmful consequences for intellectual capacity caused by poor adherence to dietary treatment could explain the observed decrease in all HRQoL scales, especially in school functioning. Healthcare system and financial difficulties may also have influenced negatively all HRQoL dimensions.

Evaluación neuropsicológica en niños y adolescentes con fenilcetonuria e hiperfenilalaninemia y su relación con los niveles de fenilalanina plasmática / Neuropsychological assessment among children and adolescents with phenylketonuria and hyperphenylalaninemia and its relationship with plasma phenylalanine levels

Aunque, con tratamiento precoz, los pacientes con fenilcetonuria pueden presentar niveles de inteligencia normales, es importante optimizar el control dietético para mantener niveles de fenilalanina adecuados y poder desarrollar su potencial intelectual sin alteraciones en sus tareas diarias por déficits en las funciones ejecutivas. Se presenta una serie de 26 pacientes, diagnosticados y tratados precozmente, a quienes se realizó una evaluación psicométrica junto con determinaciones de fenilalanina a lo largo de su vida y en el momento de realización de los tests. Se observa una tendencia a la relación inversa entre el cociente intelectual y la fenilalanina concurrente, la mediana de fenilalanina y el cociente fenilalanina/tirosina, así como una tendencia a la relación negativa entre las funciones ejecutivas y los valores de fenilalanina concurrentes y durante la vida.

Although with early treatment phenylketonuria patients may have average intelligence levels, it is important to optimize the nutritional management to maintain adequate phenylalanine levels, so that patients can develop their intellectual potential free of abnormalities in their daily activities due to deficits of cognitive executive functions. This study presents a series of 26 patients, diagnosed and treated early, who underwent a psychometric evaluation together with phenylalanine determinations along their lives, and at the time of doing the tests. A trend is observed towards a reverse relationship between IQ and concurrent phenylalanine concentration, phenylalanine median and phenylalanine/tyrosine ratio. Likewise, a trend towards a negative relationship is observed between executive functions and concurrent phenylalanine values along patients' lives.

Uso de fórmula nutricional libre de fenilalanina en pacientes con diagnóstico de fenilcetonuria / Use of phenylalanine-free nutritional formula in patients diagnosed with phenylketonuria

INTRODUCCIÓN: Antecedentes: El presente informe expone la evaluación del producto Fórmula nutricional libree de fenilalanina respecto a su uso en pacientes con diagnóstico de fenilcetonuria (PKU). Aspectos Generales: La fenilcetonuria (PKU) es un error innato del metabolismo provocado por mutaciones en el gen fenilalanina hidroxilasa (PAH), encargado de codificar la enzima PAH. La enzima PAH participa en la vía metabólica principal de la fenilalanina, un aminoácido esencial. La función de la enzima es hidroxilar la fenilalanina en tirosina en conjunto con el cofactor BH4, y oxigenio. Las mutaciones en el gen de PAH provocan una disminución o eliminación de la actividad enzimática de la PAH, por onde, niveles elevados de fenilalanina sérica, conocido como hiperfenilalaninemia. Tecnología Sanitaria de Interés: Formula nutricional libre de fenilalanina: Las fórmulas nutricionales libres de fenilalanina son alimentos médicos que forman parte del grupo de sustitutos o equivalentes de proteínas destinados para pacientes con PKU. Los alimentos médicos se definen como "un alimento formulado para ser consumido o adminitrado vía enteral bajo supervisión médica, y está dirigido para el manejo dietético de una enfermedad o condición para la cual los requerimientos nutricionales son establecidos por una evaluación médica. Los alimentos médicos para pacientes con PKU han sido modificados para elimiar el aminoácido fenilalanina de su composición a través de hidrólisis enzimáticas y procesos bioquímicos que incluyen el uso de filtraciones por gel, resinas de poliestireno, ultrafiltración, entre otros. METODOLOGIA: Estrategia de Búsqueda: Se realizó una búsqueda de literatura científica en relación al uso de fórmulas nutricionales libre de fenilalanina en pacientes menores de 15 años con diagnóstico de fenilcetonuria. Se dio preferencia a guías de práctica clínica, revisiones sistemáticas con o sin meta-análisis y ensayos clínicos aleatorizados. Asimismo, se consideró extraer información con una estrategia de "bola de nieve" mediante la revisión de listas de referencias de las guías de práctica clínica, revisiones sistemáticas, estudios primarios y revisiones narrativas seleccionadas. RESULTADOS: Se realizó la búsqueda bibliográfica y de evidencia científica que sustende el uso de una formula libre de fenilalanina en pacientes menores de 15 años con diagnóstico de PKU. Luego de revisar un total de 1073 referencias resultados de la búsqueda bibliográfica, logramos filtrar 29 estudios. Luego, tres referencias fueron finalmente seleccionadas para ser analizadas. Sinopsos de la Evidencia: Se sintetiza la evidencia considerada para el presente dictamen que sustenta el uso de fórmulas nutricionales libres de fenilalanina en pacientes menores de 15 años con PKU, en las Guías de Práctica Clínica, Revisiones Sistemáticas, Ensayos Clínicos, Ensayos Clínicos no publicados, Estudios observacionales. CONCLUSIONES: En la presente evaluación de tecnología sanitaria se presenta la evidencia recabada sobre el benefício de las fórmulas nutricionales libres de fenilalanina en pacientes menores de 15 años con Fenilcetonuria (PKU). No se encontró evidencia que compara el uso de fórmulas libres de fenilalanina con fórmulas estándar en pacientes menores de 15 años; sin embargo, se hallaron dos GPC, de alta y baja calidad metodológica, y un artículo de recomendación tipo revisión sistemática que recomiendan su uso en pacientes con PKU. El Instituto de Evaluación de Tecnologías en Salud e Investigación-IETSI, aprueba el uso de la fórmula libre de fenilalanina en pacientes menores de 15 años con diagnóstico de PKU. El presenta Dictamen Preliminar tiene una vigencia de dos años a partir de la fecha de publicación.

¿Qué debe saber el pediatra de las hiperfenilalaninemias? / What should the paediatrician know about hyperphenylalaninaemia?

Las hiperfenilalaninemias se definen por un nivel sanguíneo de fenilalanina sobre 2 mg/dl. La principal causa es una mutación en el gen que codifica la fenilalanina hidroxilasa que cataliza la reacción que transforma la fenilalanina en tirosina. Las hiperfenilalaninemias se clasifican en benignas o leves, y las fenilcetonurias en leves, moderadas y clásicas. Debido a que su detección más allá del periodo neonatal causa retardo mental severo, desde 1992 en Chile su detección, junto con la del hipotirodismo congénito, es parte del Programa Nacional de Pesquisa Neonatal. Este artículo pretende responder las preguntas más comunes que se puede hacer el pediatra cuando enfrenta a un paciente con hiperfenilalaninemias.

Hyperphenylalaninaemias are defined by a blood phenylalanine over 2 mg/dl. The main cause is due to a mutation in the gene that codes the phenylalanine hydroxylase that catalyses the reaction that converts phenylalanine into tyrosine. The hyperphenylalaninaemias are classified into benign or mild hyperphenylalaninaemias, or mild, moderate or classic phenylketonurias. Due to its delayed detection outside the neonatal period it causes severe mental retardation. Its detection along with congenital hypothyroidism has been part of the National Neonatal Screening Program since 1992 in Chile. This article aims to answer the most common questions asked by the paediatrician when faced with a patient with hyperphenylalaninaemias.

Metabolic syndrome in children and adolescents with phenylketonuria / Síndrome metabólica em crianças e adolescentes com fenilcetonúria

OBJECTIVE: This study aimed to identify markers of metabolic syndrome (MS) in patients with phenylketonuria (PKU). METHODS: This was a cross-sectional study consisting of 58 PKU patients (ages of 4-15 years): 29 patients with excess weight, and 29 with normal weight. The biochemical variables assessed were phenylalanine (phe), total cholesterol, HDL-c, triglycerides, glucose, and basal insulin. The patients had Homeostasis Model Assessment (HOMA) and waist circumference assessed. RESULTS: No inter-group difference was found for phe. Overweight patients had higher levels of triglycerides, basal insulin, and HOMA, but lower concentrations of HDL-cholesterol, when compared to the eutrophic patients. Total cholesterol/HDL-c was significantly higher in the overweight group. A positive correlation between basal insulin level and HOMA with waist circumference was found only in the overweight group. CONCLUSION: The results of this study suggest that patients with PKU and excess weight are potentially vulnerable to the development of metabolic syndrome. Therefore, it is necessary to conduct clinical and laboratory monitoring, aiming to prevent metabolic changes, as well as excessive weight gain and its consequences, particularly cardiovascular risk. .

OBJETIVO: Determinar marcadores bioquímicos da síndrome metabólica em pacientes com PKU. MÉTODOS: Foram avaliados dois grupos de pacientes com PKU, de quatro a 15 anos, com excesso de peso (29) e eutróficos (29). As variáveis bioquímicas avaliadas foram fenilalanina (phe), colesterol total, HDL-c, triglicérides, glicose e insulina basal. Foi determinado o Homa e mensurada a circunferência da cintura. RESULTADOS: As concentrações de phe, de colesterol total e de glicose foram equivalentes entre os grupos. Os pacientes com excesso de peso apresentaram maiores concentrações de triglicérides, de insulina basal, maiores valores da determinação do Homa, menores concentrações de HDL colesterol e valores mais elevados da relação do colesterol total/HDL-c. Houve correlação positiva entre a dosagem de insulina basal e do Homa com a circunferência da cintura nos pacientes do grupo com excesso de peso. CONCLUSÕES: Os resultados deste estudo sugerem que pacientes com PKU e excesso de peso são potencialmente vulneráveis ao desenvolvimento da síndrome metabólica. Há, portanto, necessidade de acompanhamento clínico-laboratorial que previna as alterações metabólicas, o ganho excessivo de peso e as suas consequências, em especial o risco cardiovascular. .

Serum phenylalanine in preterm newborns fed different diets of human milk, / Fenilalanina plasmática em recém-nascidos pré-termo alimentados com diferentes dietas de leite humano,

Objective: To evaluate phenylalanine plasma profile in preterm newborns fed different human milk diets. Methods: Twenty-four very-low weight preterm newborns were distributed randomly in three groups with different feeding types: Group I: banked human milk plus 5% commercial fortifier with bovine protein, Group II: banked human milk plus evaporated fortifier derived from modified human milk, Group III: banked human milk plus lyophilized fortifier derived from modified human milk. The newborns received the group diet when full diet was attained at 15 ± 2 days. Plasma amino acid analysis was performedon the first and last day of feeding. Comparison among groups was performed by statistical tests: one way ANOVA with Tukey's post-test using SPSS software, version 20.0 (IBM Corp, NY, USA), considering a significance level of 5%. Results: Phenylalanine levels in the first and second analysis were, respectively, in Group I: 11.9 ± 1.22 and 29.72 ± 0.73; in Group II: 11.72 ± 1.04 and 13.44 ± 0.61; and in Group III: 11.3 ± 1.18 and 15.42 ± 0.83 μmol/L. Conclusion: The observed results demonstrated that human milk with fortifiers derived from human milk acted as a good substratum for preterm infant feeding both in the evaporated or the lyophilized form, without significant increases in plasma phenylalanine levels in comparison to human milk with commercial fortifier. .

Objetivo: Avaliar o perfil plasmático do aminoácido fenilalanina em recém-nascidos pré-termo alimentados com diferentes dietas de leite humano. Métodos: Foram estudados 24 recém-nascidos pré-termo de muito baixo peso, distribuídos em três grupos com diferentes dietas: Grupo I: leite humano de banco com 5% de aditivo comercial para leite humano com proteína de origem bovina (LHB-AC); Grupo II: leite humano de banco com aditivo de leite humano modificado evaporado (LHB-E); e Grupo III: leite humano de banco com aditivo de leite humano modificado liofilizado (LHB-L). Os recém-nascidos receberam a dieta definida para o grupo quando alcançaram dieta plena por 15 ± 2 dias. A análise do aminoácido plasmático foi feita no primeiro e último dias da dieta. A comparação entre os grupos foi realizada por meio do teste ANOVA de uma via, seguido pelo pós-teste de Tukey, utilizando-se o software SPSS (IBM Corp, NY, EUA), versão 20.0, e considerando um nível de significância de 5%. Resultados: As concentrações plasmáticas do aminoácido fenilalanina na primeira e segunda análises foram, respectivamente, no Grupo I (LHB-AC) 11,9±1,22 e 29,72±0,73; no Grupo II (LHB-E) 11,72±1,04 e 13,44±0,61; e no Grupo III 11,3±1,18 e 15,42±0,83 umol/L. Conclusão: Os resultados encontrados demonstram que o leite humano com aditivos do próprio leite humano comportou-se como um bom substrato para alimentação do recém-nascido pré-termo, tanto na forma evaporada como liofilizada, sem levar a aumentos significativos na concentração plasmática de fenilalanina em comparação ao leite humano com aditivo comercial. .

Evaluation of effectiveness and outcome of PKU screening and management in the State of Sergipe, Brazil / Avaliação da eficiência e desfecho da triagem e manejo da PKU no Estado de Sergipe, Brasil

Objectives: Phenylketonuria (PKU) was the first inherited metabolic disease known to cause mental retardation for which a newborn screening program (NBS) was developed. The objective of this study was to evaluate the effectiveness of PKU NBS and the management of cases in the northeastern Brazilian state of Sergipe (SE).Materials and methods: We reviewed the phenylalanine concentrations in filter-paper collected from the heel (PKUneo) of 43,449 newborns; blood concentrations obtained by venipuncture in the subjects with abnormal PKUneo; the children’s age at several phases of the program, the incidence of the disease from January 2007 to June 2008; and metabolic control of the patients.Results: The coverage of NBS/SE was 78.93%. The children’s age was 10 ± 7 days at PKUneo collection. Twelve children were recalled based on the PKUneo cutoff value at 28 ± 13 days. From these, the concentrations of phenylalanine collected by venipuncture were normal in five children. The incidence of hyperphenylalaninemia was 1/43,449, and of PKU was 1/8,690 (5 cases). One suspected subject died. Another death occurred in the cohort, in a confirmed PKU case. PKU treatment began within 51 ± 12 days of life. In the four patients under dietary phenylalanine restriction, metabolic control was often difficult.Conclusions: PKU NBS/SE has satisfactory coverage and adequate cutoff for recalling patients and diagnosis, but the onset of treatment is delayed, and follow-up metabolic control is frequently inadequate.

Objetivos: A fenilcetonúria (PKU) foi a primeira causa metabólica hereditária de retardamento mental para a qual foi desenvolvido um programa de triagem em recém-nascidos (NBS). O objetivo deste estudo foi avaliar a eficácia do NBS para a PKU e o manejo dos casos em Sergipe (SE), Brasil.Materiais e métodos: Revisamos as concentrações de fenilalanina no filtro de papel coletado do calcanhar (PKUneo) de 43.449 recém-nascidos, suas concentrações de sangue obtidas por punção venosa em indivíduos com PKUneo anormal, a idade das crianças em diversas fases do programa, a incidência da doença no período de janeiro de 2007 a junho de 2008 e o controle metabólico dos pacientes.Resultados: A cobertura da NBS/SE foi de 78,93%. A idade das crianças era de 10 ± 7 dias na coleta de PKUneo. Doze crianças foram reconvocadas com base no ponto de corte de PKUneo aos 28 ± 13 dias de idade. Destas, as concentrações de fenilalanina por venipunctura foram normais em cinco. A incidência da hiperfenilalaninemia foi 1/43.449 e de PKU foi 1/8.690 (5 casos), e um indivíduo suspeito foi a óbito. Outro óbito ocorreu na coorte em um caso de PKU confirmado. O tratamento para a PKU começou com 51 ± 12 dias. Nos quatro pacientes sob restrição de fenilalanina alimentar, o controle metabólico foi frequentemente difícil.Conclusões: PKU NBS/SE apresenta uma cobertura satisfatória e ponto de corte adequado para reconvocação e diagnóstico, mas o início do tratamento é atrasado e o controle no seguimento é frequentemente inadequado.

Relação entre níveis de fenilalanina, inteligência e condição socioeconômica de pacientes com fenilcetonúria / Relationships between phenylalanine levels, intelligence and socioeconomic status of patients with phenylketonuria

OBJETIVOS: Avaliar inteligência e relação com concentrações sanguíneas de fenilalanina e condição socioeconômica de fenilcetonúricos entre 6 e 12 anos em tratamento. MÉTODOS: Sessenta e três crianças, classificadas por níveis de fenilalanina e condição socioeconômica, realizaram Wechsler Intelligence Scale for Children. Utilizou-se o programa Statistical Package for the Social Sciences (SPSS) para analisar níveis de fenilalanina; testes ANOVA para avaliar quociente de inteligência (QI) e níveis de fenilalanina; e regressão logística ordinal para avaliar chances de melhor desempenho em QI. RESULTADOS: Classificaram-se entre limítrofe e nível muito superior em QI total, 90,5% das crianças; em QI verbal, 96,8%; em QI de execução, 92,1%. Tiveram avaliação socioeconômica entre níveis baixo e médio superior, 98,4% das famílias. As chances de apresentar QI superior e médio foram 4,29 vezes maiores nas crianças com controle adequado e 4,03 vezes maiores nas de níveis socioeconômicos melhores. CONCLUSÕES: O tratamento preveniu o retardo mental em 90,5% dos pacientes. O controle dos níveis de fenilalanina e melhor nível socioeconômico se associaram aos melhores desempenhos em QI.

OBJECTIVES: To assess intelligence and its relationship with blood phenylalanine concentrations and socioeconomic status in patients with phenylketonuria after 6 to 12 years of treatment. METHODS: Sixty-three children were classified according to phenylalanine levels and socioeconomic status and assessed using the Wechsler Intelligence Scale for Children. The Statistical Package for the Social Sciences (SPSS) was used to analyze phenylalanine; ANOVA was used to analyze intelligence quotients (IQ) and phenylalanine levels; and ordinal logistic regression was used to analyze the likelihood of higher IQ. RESULTS: The overall IQ scores of 90.5% of the children were within a range from borderline intellectual deficiency to very high intelligence; for verbal IQ this proportion was 96.8% and 92.1% had performance IQ scores within this band. The categories from low to upper-medium socioeconomic status contained 98.4% of patients' families. The likelihood of having medium to high IQ was 4.29 times greater for children with good phenylalanine control and 4.03 greater for those from higher socioeconomic strata. CONCLUSIONS: Treatment prevented mental retardation in 90.5% of the patients. Control of phenylalanine levels and higher socioeconomic status were associated with higher IQ scores.

Acompanhamento do aleitamento materno no tratamento de crianças com fenilcetonúria / Breastfeeding follow-up in the treatment of children with phenylketonuria

A fenilcetonúria (PKU) ocorre na incapacidade para transformar fenilalanina em tirosina, trazendo efeitos tóxicos para o sistema nervoso central. Tradicionalmente, no tratamento da PKU, o aleitamento materno é substituído por fórmula láctea. Este estudo verificou os efeitos do aleitamento materno como fonte de fenilalanina no desenvolvimento de crianças com PKU. Participaram dez lactentes com PKU, que iniciaram o tratamento com a introdução de fórmula láctea antes dos 30 dias e que mantiveram o aleitamento materno por no mínimo 30 dias de vida após o início dos procedimentos. Os procedimentos basearam-se em estimar a ingestão de leite materno, com margem segura da concentração da fenilalanina, calculando o volume gástrico e oferecendo inicialmente fórmula láctea, seguida do aleitamento materno em demanda livre, em todas as mamadas. O tempo de amamentação variou de um mês e cinco dias a 14 meses. Os controles sanguíneos foram semanais. Se o nível sérico da fenilalanina estivesse >2 mg/dL e <6 mg/dL mantinha-se a prescrição; se estivesse <2 mg/dL, diminuía-se a fórmula láctea em 25%, aumentando indiretamente o aleitamento materno; se estivesse >6 mg/dL, aumentava-se a fórmula em 50%. Avaliou-se os níveis de fenilalanina, aplicou-se a Early Language Milestone Scale e Passos Básicos do Desenvolvimento. Foram considerados adequados aqueles lactentes que apresentaram índices normativos em todas as avaliações. Dos lactentes, 80% conseguiram manter limites seguros da fenilalanina e desenvolvimento nos índices normativos. Há viabilidade da continuidade do aleitamento materno no tratamento de crianças com PKU desde que os níveis de fenilalanina sejam rigorosamente controlados e que os efeitos do aleitamento materno para o desenvolvimento infantil sejam verificados.

Phenylketonuria (PKU) is the inability to convert phenylalanine into tyrosine, causing toxic effects to the central nervous system. Traditionally, in the treatment of PKU, breastfeeding is replaced by formula milk. This study verified the effects of breastfeeding as a source of phenylalanine on the development of children with PKU. Participants were ten infants with PKU who started treatment with the introduction of formula before 30 days of life, and maintained breastfeeding for at least 30 days after the start of procedures. The procedures were based on estimating breast milk intake, with a safe margin of phenylalanine concentration, calculating stomach volume, and initially offering formula, then breastfeeding on free demand, at every feeding. Breastfeeding duration ranged from one month and five days to 14 months. Blood controls were tested weekly. If the serum level of phenylalanine was >2 mg/dL and <6 mg/dL, the prescription was kept; if it was >2 mg/dL, the formula was decreased by 25%, indirectly increasing breastfeeding; if it was <6 mg/dL the formula was increased by 50%. The phenylalanine levels were assessed, and the Early Milestone Scale and the Basic Steps of Development were applied. Those who had normative index in all evaluations were considered adequate. Eighty percent of infants were able to keep safe concentrations of phenylalanine and development within normal indices. Continued breastfeeding is viable in the treatment of children with PKU, provided that phenylalanine levels are strictly controlled and the effects of breastfeeding on child development are monitored.

Responsividade à tetrahidrobiopterina em pacientes com deficiência de fenilalanina hidroxilase / Tetrahydrobiopterin responsiveness of patients with phenylalanine hydroxylase deficiency

OBJETIVO: Identificar indivíduos responsivos à tetrahibrobiopterina (BH4) em uma amostra de pacientes brasileiros com hiperfenilalaninemia por deficiência de fenilalanina-hidroxilase (HPA-PAH). MÉTODOS: Estudo intervencional, amostragem por conveniência. Para serem incluídos no estudo, os pacientes deveriam: possuir diagnóstico bioquímico de HPA-PAH; ter idade > 7 anos; estar em tratamento dietético; e apresentar níveis de fenilalanina (Phe) > 6 mg/dL em todas as medidas realizadas no ano anterior à inclusão no estudo. Os níveis de Phe foram determinados por meio de espectrometria de massas in tandem no dia anterior (dia 1) e nos pontos de hora 0, 4 e 8 h (dia 2) e 24 h (dia 3) após ingestão de BH4. Os critérios utilizados para definir responsividade ao BH4 foram: critério 1-redução > 30 por cento de Phe após 8 h da administração de BH4; e critério 2-redução > 30 por cento de Phe após 24 h da administração. RESULTADOS: Dezoito pacientes foram incluídos no estudo (mediana de idade = 14 anos, sexo masculino = 12). Cinco pacientes foram responsivos ao BH4, sendo três (forma clássica: um; forma leve: dois) de acordo com ambos os critérios, e dois (forma clássica: um; forma não definida: um) de acordo com o critério 2. Os níveis de Phe plasmáticos do dia 1 não demonstraram variação nos pontos de hora (p = 0,523). Entretanto, quando comparamos os níveis de Phe nos pontos de hora dos dias 1 e 2, encontramos uma variação significativa (p = 0,006). A análise da associação genótipo-fenótipo confirmou o caráter multifatorial da responsividade ao BH4. CONCLUSÃO: Os nossos achados estão de acordo com a literatura e indicam que um número relevante de pacientes brasileiros com HPA-PAH é responsivo à BH4.

OBJECTIVE: To identify patients responsive to tetrahydrobiopterin (BH4) in a sample of Brazilians with hyperphenylalaninemia due to phenylalanine hydroxylase deficiency (HPA-PAH). METHODS: Interventional study, convenience sampling. The inclusion criteria were: diagnosis of HPA-PAH; age > 7 years; phenylalanine-restricted diet and phenylalanine (Phe) levels > 6 mg/dL in all blood tests 1 year before inclusion. Blood samples were obtained the day before (day 1) and at 0, 4, 8 (day 2) and 24 h (day 3) after BH4 intake. Phe levels were measured using tandem mass spectrometry. The criteria used to define responsiveness to BH4 were: criterion 1- Phe reduction > 30 percent 8 h after BH4 administration; criterion 2 - Phe reduction > 30 percent 24 h after BH4 administration. RESULTS: Eighteen patients were enrolled (median age, 14 years; 12 boys). Five patients were responsive to BH4, 3 according to both criteria (one classical PKU, two mild PKU); and two according to criterion 2 (one classical PKU; one indefinite PKU type). There were no differences between Phe serum levels on day 1 and at the other time points (p = 0.523). However, Phe levels on days 1 and 2 were significantly different (p = 0.006). The analysis of the phenotype-genotype association confirmed its multifactorial character. CONCLUSION: A relevant number of Brazilian patients with HPA-PAH are responsive to BH4, in agreement with other studies in the literature.

Desempenho de crianças com fenilcetonúria no Teste de Screening de Desenvolvimento Denver - II / Performance of children with phenylketonuria in the Developmental Screening Test - Denver II

TEMA: desempenho de crianças com PKU no Teste de Screening de Desenvolvimento Denver - II. Introdução: a fenilcetonúria é uma desordem autossômica recessiva resultante da mutação do gene localizado no cromossomo 12q22.24.1. OBJETIVO: caracterizar o desempenho de crianças com fenilcetonúria diagnosticadas e tratadas precocemente por meio do Teste de Screening de Desenvolvimento Denver II e dos níveis de fenilalanina sanguíneos. MÉTODO: participaram 20 crianças, dez com fenilcetonúria, diagnosticadas e tratadas desde o nascimento, de idade cronológica entre três a seis anos, e dez crianças do grupo típico, pareadas quanto ao sexo, idade e nível socioeconômico. Os níveis sanguíneos e as informações neurológicas, psicológicas e sociais foram obtidas no banco de dados do Programa de Triagem Neonatal para Erros Inatos do Metabolismo. A avaliação constou da aplicação do Teste de Screening de Desenvolvimento Denver-II. Utilizou-se estatística descritiva e aplicação do teste estatístico de Mann Whitney para a caracterização das habilidades. Para as medições dos níveis plasmáticos sanguíneos de fenilalanina considerou-se os valores abaixo de 2mg/dL, acima de 4mg/dL, os valores de referência entre 2 e 4mg/dL, de todos os exames realizados no decorrer da vida dos participantes, os valores mínimos e máximos e o valor obtido na época da avaliação fonoaudiológica. Resultado: A comparação entre os grupos foi estatisticamente significante nas áreas pessoal-social e de linguagem. CONCLUSÃO: crianças com fenilcetonúria diagnosticadas e tratadas precocemente apresentaram prejuízo nas áreas pessoal-social e de linguagem e, mesmo com o acompanhamento periódico, apresentaram dificuldades para manter os níveis de normalidade de fenilalanina, embora realizassem o tratamento recomendado.

BACKGROUND: phenylketonuria is an autosomal recessive disorder resulting from the mutation of a gene located in chromosome 12q22-24.1. AIM: to describe the performance of children with classic phenylketonuria, who were diagnosed and treated early, in the Development Screening Test Denver - II. METHOD: participants were 20 children with phenylketonuria, ranging in age from 3 and 6 years, and 10 children with typical language development, paired by gender, age and socioeconomic level to the research group. The plasmatic phenylalanine measure and the neurological, psychological and social information were gathered in the data base of the Neonatal Screening Programs for Metabolic disorder. Assessment consisted on the application of the Development Screening Test Denver II. A descriptive statistical analysis and the Mann Whitney test were used in order to characterize the tested skills. For the measurements of the plasmatic phenylalanine blood levels the values considered for analysis were: below 2mg/dL, above 4mg/dL, reference values between 2 and 4mg/dL, of all exams performed during the participants'lives; maximum and minimum values and values obtained on the day of the screening application. RESULTS: comparison between the groups indicated statistically significant differences for the personal-social and language areas. CONCLUSION:children who were diagnosed and treated early for phenylketonuria present deficits in the personal-social and language areas. Also, even when receiving follow-up and undergoing treatment, these children presented difficulties in maintaining normal plasmatic phenylalanine levels.

Association of EEG abnormality and developmental delay in phenylketonuria [PKU]: an analytic historical case-control study

Electroencephalogram [EEG] is an easy and non invasive evaluation method for diagnosis and early prognosis in children. Our aim was to assess the association between EEG and the patients' Developmental Quotient [DQ] level in phenylketonuria. In this study, 94 PKU patients [45 boys, 49 girls; mean age 8.5 +/- 6.2 years] who were diagnosed through newborn screening tests or later were followed. PKU was confirmed with a serum phenylalanie concentration above 6 mg/dl in untreated newborns. The patients were matched in gender, age and phenylalanine level. The ASQ [Age and Stage Questionnaire] was used for evaluation of the developmental stage of the case [abnormal EEG] and control [normal EEG] groups and the Wechsler Intelligence Scale was used to assess cognitive and intellectual abilities. Finally, one way ANOVA and chi square tests were used for analysis and P<0.05 was considered significant. The case group consisted of 63 patients [67%] with abnormal EEGs and the control group consisted of 31 patients [33%] with normal EEGs. In patients with abnormal EEGs, 34 [53%] had mile, nine [14% had moderate and 20 [33%] had severe EEG changes. Distribution of high and low DQ levels in the abnormal and normal EEG patients showed a significant difference [p=0.001]. There was no significant difference between phenylalanine level in case and control groups; therefore, EEG findings may affect patients' developmental scores despite a normal phenylalanine level in PKU patients

Incidence of neonatal hyperphenylalaninemia in pars province, South Iran

Phenylalanine hydroxylase or its cofactor, tetrahydrobiopterin [BH[4], deficiency causes accumulation of phenylalanine in body fluids and central nervous system. Considering the fact that hyperphenylalaninemia is a preventable cause of mental retardation in infants, the objective of this study was to determine the incidence of congenital hyperphenylalaninemia in Pars province, south of Iran. In a period of one year from November 2007 to November 2008 blood samples were withdrawn from all newborns born in Pars province for measurement of serum phenylalanine. The samples with a serum level of >/= 2 mg/dl were referred to pediatric endocrine clinic for confirmation and determination of the type of hyperphenylalaninemia by quantitive serum phenylalanine measurements by using High-Pressure liquid chromatography [HPLC] method. Nine out of 76966 newborns had a serum phenylalanine level >/= 2mg/dl, of which 8 cases were confirmed by HPLC. The incidence of the disease was 1:10000. The incidence of mild hyperphenylalaninemia and phenylketonuria [PKU] among the patients was 62.5% and 37.5% respectively and the incidence of BH4 deficiency was 1/76966. These findings indicate a high incidence of hyperphenylalaninemia, in the newborns from Pars province. The high incidence makes a comprehensive screening program "for management of the disease necessary

[Phenylketonuria and its dietary therapy in children]

Phenylketonuria [PKU] is the most common autosomal recessive disease. Hyperphenylalaninemia is caused by deficiency or inactivity of the phenylalanine hydroxylase in liver. In this disorder phenylalanine in not metabolized to tyrosine. Increased levels of blood phenylalanine causes irreversible brain damage. As infants with PKU do not show any clinical signs in the postnatal period, first stage in treatment is an effective screening and diagnosis. Main treatment of PKU is diet therapy, which should be initiated before the third week of life and monitored by a team formed of a pediatrician, an experienced dietitian, a psychologist, a social worker and a nurse. Phenylalanine-restricted diet should provide enough protein-energy and other nutrients for an optimal growth and brain development and include tyrosine supplement to preserve the phenylalanine plasma concentration in a range of 2 to 6 mg/dl. The exact amount should be prescribed based on age, specific genotype, growth rate and individual need for energy. Successful management of PKU patients should be monitored by growth rate. Duration of diet therapy is controversial; continuing phenylalanine-restricted diet beyond adolescence is recommended

A novel missense mutation pattern of the GCH1 gene in dopa-responsive dystonia

Dopa-responsive dystonia (DRD) is an inherited metabolic disorder now classified as DYT5 with two different biochemical defects: autosomal dominant GTP cyclohydrolase 1 (GCH1) deficiency or autosomal recessive tyrosine hydroxylase deficiency. We report the case of a 10-years-old girl with progressive generalized dystonia and gait disorder who presented dramatic response to levodopa. The phenylalanine to tyrosine ratio was significantly higher after phenylalanine loading test. This condition had two different heterozygous mutations in the GCH1 gene: the previously reported P23L mutation and a new Q182E mutation. The characteristics of the DRD and the molecular genetic findings are discussed.

Distonia dopa-responsiva (DRD), classificada como DYT5, é um erro inato do metabolismo que pode ser causado por dois diferentes tipos de defeito bioquímico: deficiência de GTP ciclo-hidrolase 1 (GCH1) (autossômica dominante) ou de tirosina hidroxilase (autossômica recessiva). Descrevemos o caso de menina de 10 anos com distonia generalizada progressiva e alteração da marcha com importante melhora após uso de levodopa. A relação fenilalanina/tirosina estava aumentada após teste de sobrecarga com fenilalanina. O estudo molecular mostrou que o paciente apresenta uma combinação hererozigótica de mutação no gene GCH1: a já conhecida mutação P23L e uma nova mutação Q182E. Discutem-se as características da DRD e as alterações genéticas possíveis.

O aleitamento materno no tratamento de crianças com fenilcetonúria / Breastfeeding in the treatment of children with phenylketonuria

OBJETIVO: Avaliar o efeito do leite materno como fonte de fenilalanina (phe) nos níveis sangüíneos desse aminoácido e no crescimento de fenilcetonúricos. MÉTODOS: Foram estudados 35 fenilcetonúricos que mantiveram leite materno, e os resultados foram comparados com os de 35 lactentes que usaram fórmula láctea comercial. Os grupos foram pareados por sexo e por idade à suspensão do aleitamento materno. Os dados foram analisados até a suspensão do leite materno ou durante 12 meses de acompanhamento. O grupo amamentado recebeu "fórmula especial" isenta em phe, em mamadeira a cada 3 horas, e leite materno em livre demanda nos intervalos. Os níveis sangüíneos de phe, coletados semanalmente até 6 meses e quinzenalmente até 1 ano de idade, foram analisados durante a amamentação. Foram comparados o tempo necessário para adequação dos níveis sangüíneos de phe, após o início do tratamento, utilizando o teste de Wilcoxon e os dados antropométricos, pelo teste t de Student pareado, utilizando o escore z. As dosagens de phe foram analisadas durante a amamentação. RESULTADOS: O tempo mediano para adequação dos níveis de phe no sangue foi de 8 dias para o grupo amamentado e de 7 dias para o grupo controle. As dosagens de phe estavam adequadas em 87 por cento das vezes para o grupo amamentado e em 74,4 por cento para o grupo controle. Na avaliação antropométrica, a maioria das crianças, de ambos os grupos, apresentou escore z > -2. CONCLUSÃO: A manutenção do aleitamento materno, durante o tratamento, mostrou-se adequada no controle metabólico e no crescimento das crianças fenilcetonúricas.

OBJECTIVE: To evaluate the effect of breastmilk as a source of phenylalanine (phe) on levels of this amino acid and on growth in phenylketonuric infants. METHODS: The study recruited 35 breastfed phenylketonuric infants and compared their results with those of 35 infants fed on commercial, milk-based formula. The groups were paired for sex and age at weaning from breastfeeding. Data were analyzed up until cessation of breastmilk or for 12 months' follow-up. The breastfed group were given a "special formula" free of phe, by bottle every 3 hours, and breastmilk at will during the intervals. Levels of phe in the blood, collected weekly up to 6 months and fortnightly up to 1 year de age, were analyzed while breastfeeding continued. The two groups were compared in terms of the time taken for the levels of phe in blood to return to normal after treatment was started, using the Wilcoxon test. Anthropometric data were compared with Student's t paired test in the form of z scores. The phe assays were analyzed throughout breastfeeding. RESULTS: The median time taken for phe levels to return to normal was 8 days for the breastfed group and 7 days for the control group. The phe assay results were normal in 87 percent of tests for the breastfed group and in 74.4 percent for the control group. The majority of children in both groups exhibited a z score > -2 on anthropometric examination. CONCLUSIONS: Continuation of breastfeeding, during the treatment, proved adequate for metabolic control and growth in children with phenylketonuria.

Evolución clínica de niños con niveles plasmáticos de fenilalanina entre 2.1 y 6.0 mg/dl en el período neonatal / Clinical evolution of children with phenylalanine plasma levels between 2.1 and 6.0 mg/dl during the neonatal period

Introducción: La Academia Americana de Pediatría (AAP) ha clasificado la Fenilquetonuria (PKU) e Hiperfenilalaninemia (HFA) según la tolerancia de la ingesta de fenilalanina (FA) en: PKU clásica: 20 mg FA/kg/día, PKU moderada: 21 y 25 mg FA/kg/día y PKU leve: 25 y 50 mg FA/kg/día, e HFA benigna con dieta normal, manteniendo un nivel plasmático de FA entre 2,0 y 10,0 mg/dl. Objetivo: Evaluar la evolución clínica de 67 niños con valores de FA plasmática entre 2.1 y 6.0 mg/dL en el período neonatal. Resultados: Del total, 29 niños tenía entre 0 y 2 años, 23 entre 2 y 4 años y 15 niños eran mayores de 4 años de edad. El estado nutricional de 45 niños era normal, 14 niños estaban con sobrepeso u obesidad, y 8 casos tenían riesgo nutricional. Se determinó que 4 niños tenían una ingesta menor de 20 mg FA/kg/día, dos niños entre 21 y 25 mg FA/kg/día, 15 casos entre los 26 a 50 mg FA/kg/día y 46 niños estaban con dieta normal. Conclusión: Los recién nacidos con niveles de FA entre 2.1 y 6.0 mg/dl durante el período neonatal, tienen una evolución clínica y nutricional diferente, que puede ir desde una PKU clásica a una HFA benigna, por lo cual se recomienda mantener un control frecuente de FA sanguínea y una vigilancia nutricional, con un mínimo de 2 años de seguimiento.

Introduction: The American Academy of Pediatric (AAP) has classified Phenylketonuria (PKU) and Hyperphenylalaninaemias (HPhe) according to tolerance of phenylalanine (Phe) intake in: Classic PKU (20 mg Phe/kg/day), moderate PKU (between 21 and 25 mg Phe/kg/day) and mild PKU (between 25 and 50 mg Phe/kg/day), and benign HPhe with normal diet, maintaining blood Phe levels between 2,0 and 10,0 mg/dL. Objective: To evaluate the clinical evolution of 67 children with blood Phe values between 2,1 and 6.0 mg/dl in the neonatal period. Results: Of the total, 29 children were aged between 0 and 2 years, 23 between 2 and 4 years and 15 children were older than 4 years of age. The nutritional state of 45 children was normal, 14 children were overweight or obese, and 8 were at nutritional risk. Four children had Phe intake below 20 mg/kg/day, two children between 21 and 25 mg/kg/day; 15 cases between 26 to 50 mg/kg/day and 46 children were on normal diet. Conclusion: Newborns with blood Phe levels between 2,1 and 6,0 mg/dl in the neonatal period, had a different clinical and nutritional evolution, which could go from the classic PKU to a benign HPhe. Thus, it is recommended to keep a frequent control of plasmatic Phe levels and nutritional monitoring for a minimum of 2 years of follow up.

Study of amino acid disorders among a high risk group of Egyptian infants and children

The present work aimed at investigating infants [in neonatal and post neonatal period] and children suspected of having inborn errors of metabolism with unexplained mental retardation. The frequency pattern of the various amino acid disorders, in a group of selected infants and children was done to document the prevalence of various amino acid disorders among Egyptian children. In this study, recent methods to investigate such disorders have been carried out by amino acid analyzer which detects levels of amino acids. Extended metabolic screen which also detects amino acid disorders, organic acid disorders and the defects of fatty acid oxidation has been carried out. These recent methods have therefore the potential of yielding information on the physiological and pathophysiological status of different metabolic pathways, as well as their interrelationship. The total number of cases attending the outpatient clinic during the period of study were 1343 index cases, among them 50 index cases [3.72%] were suspected of having inborn errors of amino acid and, 20 cases [40%] of them have confirmed positive inborn errors of amino acid metabolism. Concerning the confirmed 20 cases, their ages ranged from 5 days to 11 years with a mean of 54.75 +/- 33.09 months with equally sex distribution. The overall consanguinity rate recorded was 65%, while the family history of the similarly affected cases was 30%. The main clinical findings included mental retardation 85%, convulsions 40%, and hypo pigmentation 75%, microcephally 15%. Associated anomalies were present in 35% of cases. Among them eye anomalies were the most common [8%]. The prevalence of aminoacidopathies during the period of the study was 1.5% [of 20 studied cases], among them PKU was found to be the commonest aminoacidopathies 1.11%, while the remaining diagnosed cases representing 0.07% for each