Nonalcoholic fatty liver disease in adolescents with phenylketonuria

Abstract Objective: This study aimed to investigate non-alcoholic fatty liver disease (NAFLD) occurrence and factors associated with the disease in phenylketonuria (PKU) patients undergoing exclusive dietary treatment. Method: This cross-sectional study included 101 adolescents 10 to < 20 years of age with PKU, who were undergoing exclusive dietary treatment and monitored since early diagnosis at a single reference service. Anthropometric and biochemical assessments were performed and food intake was documented, and an ultrasound diagnosis of NAFLD was established. Data were evaluated using the Student's t-test for continuous variables, the chi-square for categorical variables, and logistic regression using the Wald chi-squared test; differences with p < 0.05 were considered to be statistically significant. Results: NAFLD was detected in 26 (25.7%) teenagers. There was no difference in prevalence between the sexes or nutritional status. The final logistic regression model revealed low sensitivity (26.1%) and high specificity (94.7%). The specificity suggested a lower likelihood of NAFLD in older adolescents, in the presence of normal or high levels of alkaline phosphatase, lower carbohydrate intake, and adequate protein and lipid intake. Conclusions: The prevalence of NAFLD in adolescents with PKU was higher than that found in healthy Brazilian adolescents and similar to that found in obese Brazilian children, suggesting a higher risk for NAFLD in patients with PKU treated exclusively by dietary modification.

Nonalcoholic fatty liver disease in adolescents with phenylketonuria.

OBJECTIVE: This study aimed to investigate non-alcoholic fatty liver disease (NAFLD) occurrence and factors associated with the disease in phenylketonuria (PKU) patients undergoing exclusive dietary treatment. METHOD: This cross-sectional study included 101 adolescents 10 to < 20 years of age with PKU, who were undergoing exclusive dietary treatment and monitored since early diagnosis at a single reference service. Anthropometric and biochemical assessments were performed and food intake was documented, and an ultrasound diagnosis of NAFLD was established. Data were evaluated using the Student's t-test for continuous variables, the chi-square for categorical variables, and logistic regression using the Wald chi-squared test; differences with p < 0.05 were considered to be statistically significant. RESULTS: NAFLD was detected in 26 (25.7%) teenagers. There was no difference in prevalence between the sexes or nutritional status. The final logistic regression model revealed low sensitivity (26.1%) and high specificity (94.7%). The specificity suggested a lower likelihood of NAFLD in older adolescents, in the presence of normal or high levels of alkaline phosphatase, lower carbohydrate intake, and adequate protein and lipid intake. CONCLUSIONS: The prevalence of NAFLD in adolescents with PKU was higher than that found in healthy Brazilian adolescents and similar to that found in obese Brazilian children, suggesting a higher risk for NAFLD in patients with PKU treated exclusively by dietary modification.

Overweight/obesity in adolescents with phenylketonuria: protective and predisposing factors

Abstract Objective: To estimate the prevalence and factors associated with overweight/obesity development in adolescents with early diagnosed phenylketonuria treated exclusively by diet. Methodology: In this cross-sectional study anthropometric measurements, serum phenylalanine levels, and 10 metabolites associated with lipid and carbohydrate metabolism were analyzed in 101 adolescents aged 10-20 years. Adolescents were categorized into overweight/obesity and eutrophic/low body mass index groups. These patients were compared using Student's t-test, Pearson's chi-square test, Wald's chi-square test for multivariate analysis. Further, to verify whether the prevalence of overweight/obesity found in the study population was similar to that in the general population, the authors compared the nutritional status of 46 patients aged 13-17 years with that of healthy students of the same age from the National School Health Survey using the chi-square test for adherence. The significance threshold was p < 0.5. Results: The prevalence of overweight/obesity in adolescents was 27.7%. There was no difference in prevalence between sexes. Older age was a protective factor and Increased Homeostasis Model Assessment Insulin Resistance index and high phenylalanine and low-density lipoprotein cholesterol levels were predictive factors for overweight/obesity. The equality hypothesis was not rejected in the comparison of nutritional states of 46 patients aged 13-17 years and healthy students of the same age. Conclusion: The prevalence of overweight/obesity in phenylketonuria adolescents was similar to what is found in healthy adolescents.

Overweight/obesity in adolescents with phenylketonuria: protective and predisposing factors.

OBJECTIVE: To estimate the prevalence and factors associated with overweight/obesity development in adolescents with early diagnosed phenylketonuria treated exclusively by diet. METHODOLOGY: In this cross-sectional study anthropometric measurements, serum phenylalanine levels, and 10 metabolites associated with lipid and carbohydrate metabolism were analyzed in 101 adolescents aged 10-20 years. Adolescents were categorized into overweight/obesity and eutrophic/low body mass index groups. These patients were compared using Student's t-test, Pearson's chi-square test, Wald's chi-square test for multivariate analysis. Further, to verify whether the prevalence of overweight/obesity found in the study population was similar to that in the general population, the authors compared the nutritional status of 46 patients aged 13-17 years with that of healthy students of the same age from the National School Health Survey using the chi-square test for adherence. The significance threshold was p < 0.5. RESULTS: The prevalence of overweight/obesity in adolescents was 27.7%. There was no difference in prevalence between sexes. Older age was a protective factor and Increased Homeostasis Model Assessment Insulin Resistance index and high phenylalanine and low-density lipoprotein cholesterol levels were predictive factors for overweight/obesity. The equality hypothesis was not rejected in the comparison of nutritional states of 46 patients aged 13-17 years and healthy students of the same age. CONCLUSION: The prevalence of overweight/obesity in phenylketonuria adolescents was similar to what is found in healthy adolescents.

Body fat percentage in adolescents with phenylketonuria and associated factors.

OBJECTIVE: To evaluate the percentage of body fat (% BF) in adolescents with PKU and to relate it to protein consumption, physical activity level, body mass index (BMI), sexual maturity and metabolic control. METHOD: This is a cross-sectional study conducted with 94 adolescents between 10 and 20 years of age, with early diagnosis and continuous treatment. Bioimpedance, weight measurements, height and BMI calculation were performed. Questionnaires were applied to quantify protein ingestion and establish the level of physical activity. Sexual maturity was assessed using the Tanner criteria. The annual mean of serum phenylalanine was used as a control parameter of the disease. A multivariate linear regression analysis was performed. RESULTS: Overweight, obesity, the female sex and the percentage of protein consumption explain 94.1% of the % BF of the patients (p < .05). The overweight prevalence was 19.1%. It was verified that 96.7% of the sample were sedentary. Only 50 (53.2%) of the adolescents had good treatment compliance, and no relationship was found between this variable and the % BF (p = .706). CONCLUSIONS: Being female and presenting high BMI values are important factors associated with % BF in phenylketonuric adolescents. Disease control and protein consumption do not seem to influence the body composition.

Frequency of biotinidase gene variants and incidence of biotinidase deficiency in the Newborn Screening Program in Minas Gerais, Brazil.

OBJECTIVE: The prevalence of biotinidase deficiency and the frequency of biotinidase gene variants in Brazil are not documented. We aimed to determine the incidence of partial and profound biotinidase deficiency in the state of Minas Gerais, Brazil, and to calculate the frequency of biotinidase gene variants in the newborn screening program of Minas Gerais. METHODS: Neonates (1,168,385) were screened from May 2013 to June 2018. Those detected with abnormal biotinidase activity based on semi-quantitative assays underwent confirmatory serum tests. The biotinidase gene was sequenced in all confirmed cases. RESULTS: The combined incidence of partial and profound biotinidase deficiency was estimated at 1:13,909 live births (95% confidence limit 1:11,235-1:17,217), much higher than the incidence rates reported in other populations worldwide. The most frequent biotinidase gene variants were p.D444H (allele frequency, 0.016), haplotype c.1330G>C;c.511G>A (p.D444H;A171T), p.D543E, c.310-15delT (intronic), p.V199M, and p.H485Q. Together these accounted for 74.6% of the alleles analysed. CONCLUSION: Newborn screening for biotinidase deficiency, which revealed a higher incidence in Minas Gerais, is feasible and plays a critical role in the early identification of affected neonates and prevention of symptoms and irreversible sequelae. Biotinidase gene sequencing is a useful tool to confirm the diagnosis, and also provides valuable information about genetic variability among different populations.

BH4 deficiency identified in a neonatal screening program for hyperphenylalaninemia / Deficiências de BH4identificadas em um programa de triagem neonatal para hiperfenilalaninemias

Abstract Objectives To show the general prevalence and to characterize tetrahydrobiopterin (BH4) deficiencies with hyperphenylalaninemia, identified by the Neonatal Screening Program of the State of Minas Gerais. Methods Descriptive study of patients with BH4 deficiency identified by the Neonatal Screening Program of the State of Minas Gerais. Results The prevalence found was 2.1 for 1,000,000 live births, with a frequency of 1.71% among hyperphenylalaninemias. There were four cases (40%) with 6-pyruvoyl-tetrahydropterin synthase deficiency, three with GTP cyclohydrolase I - autosomal recessive form deficiency, and three with dihydropteridine reductase deficiency (30% each). Six patients were diagnosed due to clinical suspicion and four cases due to systematic screening in neonatal screening. After the start of the treatment, patients identified by neonatal screening had rapid improvement and improved neuropsychomotor development compared to those diagnosed by the medical history. Conclusions The prevalence of BH4 deficiencies in Minas Gerais was slightly higher than that found in the literature, but the frequency among hyperphenylalaninemias was similar. Although rare, they are severe diseases and, if left untreated, lead to developmental delays, abnormal movements, seizures, and premature death. Early treatment onset (starting before 5 months of age) showed good results in preventing intellectual disability, justifying the screening of these deficiencies in newborns with hyperphenylalaninemia identified at the neonatal screening programs for phenylketonuria.

Resumo Objetivos Apresentar a prevalência geral e caracterizar as deficiências de tetrahidrobiopterina - BH4 - com hiperfenilalaninemia, identificadas pelo Programa de Triagem Neonatal do Estadode Minas Gerais. Métodos Estudo descritivo de pacientes com deficiência de BH4 do Programa de Triagem Neonatal do Estado de Minas Gerais. Resultados A prevalência encontrada foi de 2,1 para 1.000.000 recém-nascidos vivos e a frequência de 1,71%, dentre as hiperfenilalaninemias. Quatro casos (40%) com deficiência de 6-piruvoil-tetrahidropterina sintase, três com deficiência de GTP ciclohidrolase I e três com deficiência de dihidropteridina redutase (30% cada um). Seis pacientes foram diagnosticadospor suspeita clínica e quatro pela pesquisa sistemática na triagem neonatal. Após o início do tratamento, os pacientes identificados pela triagem neonatal tiveram melhora rápida e melhor desenvolvimento neuropsicomotor em comparação com aqueles diagnosticados pela história clínica. Conclusões A prevalência das deficiências de BH4 em Minas Gerais foi um pouco maior que a encontrada na literatura, mas a frequência, entre as hiperfenilalaninemias, foi semelhante. Embora raras, são graves e, se não tratadas, levam a atraso de desenvolvimento, movimentos anormais, convulsões e morte precoce. O tratamento precoce (início antes dos 5 meses) mostrou bons resultados na prevenção de deficiência intelectual, justificando a pesquisa dessas deficiências nos recém-nascidos com hiperfenilalaninemia pelos programas de triagem neonatalpara fenilcetonúria.

BH4 deficiency identified in a neonatal screening program for hyperphenylalaninemia.

OBJECTIVES: To show the general prevalence and to characterize tetrahydrobiopterin (BH4) deficiencies with hyperphenylalaninemia, identified by the Neonatal Screening Program of the State of Minas Gerais. METHODS: Descriptive study of patients with BH4 deficiency identified by the Neonatal Screening Program of the State of Minas Gerais. RESULTS: The prevalence found was 2.1 for 1,000,000 live births, with a frequency of 1.71% among hyperphenylalaninemias. There were four cases (40%) with 6-pyruvoyl-tetrahydropterin synthase deficiency, three with GTP cyclohydrolase I - autosomal recessive form deficiency, and three with dihydropteridine reductase deficiency (30% each). Six patients were diagnosed due to clinical suspicion and four cases due to systematic screening in neonatal screening. After the start of the treatment, patients identified by neonatal screening had rapid improvement and improved neuropsychomotor development compared to those diagnosed by the medical history. CONCLUSIONS: The prevalence of BH4 deficiencies in Minas Gerais was slightly higher than that found in the literature, but the frequency among hyperphenylalaninemias was similar. Although rare, they are severe diseases and, if left untreated, lead to developmental delays, abnormal movements, seizures, and premature death. Early treatment onset (starting before 5 months of age) showed good results in preventing intellectual disability, justifying the screening of these deficiencies in newborns with hyperphenylalaninemia identified at the neonatal screening programs for phenylketonuria.

Deficiência de vitamina B12 e fenilcetonúria / Vitamin B 12 deficiency and phenylketonuria

A fenilcetonúria, doença metabólica hereditária, autossômica recessiva, é a mais frequente das aminoacidopatias. Quando não diagnosticada e tratada precocemente, causa retardo mental grave. Os programas de triagem neonatal transformaram a histó- ria natural dessa doença, possibilitando o diagnóstico neonatal e a instituição imediata do tratamento dietético. Atualmente, os pacientes com controle adequado têm vida normal. Nas últimas décadas, alterações nutricionais têm sido relacionadas ao tratamento dietético e aos seus desvios, especialmente após a primeira década de vida. Neste artigo apresenta-se o caso de um adolescente que desenvolveu anemia megaloblástica por deficiente ingestão de vitamina B12 e uma revisão da literatura sobre o tema.(AU)

Phenylketonuria, inherited metabolic disease, autosomal recessive, is the most common of aminoacidopathies. If not diagnosed and treated early, causes severe mental retardation. The newborn screening programs have transformed the natural history of this disease, allowing the neonatal diagnosis and the immediate institution of dietary treatment. Currently, patients with adequate control have normal life. In recent decades, nutritional changes have been related to dietary treatment and its deviations, especially after the first decade of life. In this article we present the case of a teenager who developed megaloblastic anemia due to poor intake of vitamin B12 and a literature review on the topic(AU)

Children with phenylketonuria treated early: basic audiological and electrophysiological evaluation.

OBJECTIVES: Individuals with phenylketonuria (PKU) can exhibit deficits in executive functions, intelligence, attention, visual-spatial processing abilities, and efficiency stemming presumably from deficient neurotransmitter synthesis, even when the disorder is diagnosed and treated early. Basic audiological and electrophysiological evaluations were used to examine the peripheral and central auditory pathways of children with early-treated PKU, who followed adequate versus inadequate diets. Results were compared with those of age-matched children without PKU. DESIGN: The control group included 35 children aged 5 to 16 years, and the experimental group included 25 children with classic PKU, all of whom were diagnosed and treated early. The experimental group comprised children of two subgroups, divided according to their dietary control, as follows: 8 children aged 6 to 13 years with adequate diets (group A); 17 children ages 6 to 15 years demonstrating inadequate diets (group B). All participants underwent auditory evaluations, including otoscopy, pure-tone and speech audiometry, immittance testing (tympanometry and assessment of contralateral stapedial reflex thresholds), and evaluations of auditory brainstem and middle latency responses. The demographic variables and audiological examination results were analyzed for all groups. Results among groups and subgroups were compared using analysis of variance with repeated measures to test statistical significance across factors and measures at the p = 0.05 level. RESULTS: Audiometric evaluation revealed results within normal limits for all groups, except for one child from the inadequate diet group, who showed a mild bilateral conductive hearing loss. Results of speech and immittance audiometry suggested the children in group B as having poorer average speech-discrimination scores and higher stapedial reflex thresholds at 4000 Hz. Auditory brainstem response results revealed longer average latencies for waves III and V and greater interaural differences for wave V in group B, although both groups A and B showed longer average latencies for the interpeak interval I-V, compared with the control group. Middle latency responses showed no significant differences in the latencies of the Na and Pa waves or the Na-Pa amplitude for the experimental group, but electrode or ear effects were present in 87.5% of group A and 58.8% of group B. CONCLUSIONS: Overall, differences observed tended to be small (by clinical diagnostic standards), yet suggest that children with PKU exhibit some effect of this disorder on the pontine auditory pathway, even when diagnosed/treated early and independent of the appropriateness of diet. It thus seems prudent to follow PKU children with auditory processing assessments to evaluate functional implications of these findings.

Brinquedoteca: estratégia lúdica educativa complementar às ações de integralidade no Programa Estadual de Triagem Neonatal / Toy library: ludic educational strategy complementary to the actions of integrality in the Neonatal Screnning State Program

Os autores relatam as estratégias de trabalho da equipe multidisciplinar do NUPAD FM-UFMG com as crianças triadas pelo PETN-MG e atendidas no CEAPS. Salienta-se o papel da brinquedoteca como espaço lúdico e de convivência no comportamento das famílias e das criancas frente aos problemas trazidos pelas doenças crônicas.(AU)

The Centre for Social Support and Education, the CEAPS, is a space that belongs to NUPAD / FM / UFMG and aims to continue to organize social activities, care and support for patients, from the PETN-MG, as well as to their families, who must remain a long day in Belo Horizonte, pending consultations and / or special examinations.(AU)

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.

Relationships between phenylalanine levels, intelligence and socioeconomic status of patients with phenylketonuria.

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.

Crianças com fenilcetonúria: avaliação audiológica básica e supressão das otoemissões / Children with phenylketonuria: basic audiological evaluation and suppression of otoacoustic emissions

OBJETIVO: Avaliar a via auditiva de crianças com fenilcetonúria tratadas precocemente, por meio de audiometria, imitanciometria e supressão das emissões otoacústicas transientes. MÉTODOS:Estudo prospectivo transversal comparativo com amostra composta por 28 crianças, sendo 12 com fenilcetonúria e 16 sem a doença. Foi realizada a pesquisa dos limiares de audibilidade por via aérea e óssea, logoaudiometria, imitanciometria e supressão das emissões otoacústicas transientes. RESULTADOS: A audiometria e a logoaudiometria estiveram normais em todos os participantes. Foram encontrados piores resultados para o índice de reconhecimento de fala (IRF) no grupo com fenilcetonúria. A imitanciometria revelou curva normal para todas as crianças, mas a pesquisa dos reflexos estapedianos demonstrou que as crianças do grupo com fenilcetonúria apresentaram aumento nos seus limiares nas frequências de 2 e 4 kHz. A supressão das emissões otoacústicas transientes não revelou diferença na comparação entre os grupos. CONCLUSÃO: A avaliação audiológica básica não identifica alterações na audição das crianças com fenilcetonúria, mas há pior discriminação ao IRF e aumento nos limiares de reflexos estapedianos nessas crianças, podendo indicar distúrbios do processamento auditivo. O estudo da supressão das otoemissões demonstra integridade do sistema eferente olivococlear medial nas crianças com fenilcetonúria.

PURPOSE: To evaluate the auditory pathways of children with early-treated phenylketonuria through audiometry, immitance tests, and suppression of transient otoacoustic emissions. METHODS: Prospective cross-sectional study with sample composed by 28 children: 12 with phenylketonuria and 16 without the disease. Participants underwent auditory evaluations composed of air- and bone-conduction pure-tone audiometry, speech audiometry, immittance tests and suppression of transient otoacoustic emissions. RESULTS: All participants presented normal results in pure-tone and speech audiometry; however, speech discrimination scores were lower on the phenylketonuria group. Immitance tests revealed normal tympanograms for all children, but stapedial reflex thresholds demonstrated higher thresholds in 2 and 4 kHz for children with phenylketonuria. The suppresion of transient otoacoustic emissions did not show difference in the comparison between groups. CONCLUSION: The basic audiologic assessment do not identify hearing disorders in children with phenylketonuria; however, speech discrimination scores were lower and stapedial reflexes were higher in these children, which may indicate auditory processing disorders. The study of the suppression of transient otoacoustic emissions demonstrated integrity of the olivocochlear efferent system in children with phenylketonuria.

Consumo alimentar de lactentes com fenilcetonúria em uso de aleitamento materno / Nutrient intake of breastfed infants with phenylketonuria

OBJETIVO: O objetivo deste estudo foi avaliar a ingestão de calorias, fenilalanina, tirosina e proteína de lactentes com fenilcetonúria em uso de aleitamento materno. MÉTODOS: Um grupo de 39 crianças, com até 6 meses de idade, que fazia uso de aleitamento materno (grupo amamentado) foi comparado a um grupo-controle que fazia uso de fórmula especial com baixo teor de fenilanina, por meio de um estudo de coorte histórico concorrente. Os grupos foram pareados por sexo e duração da amamentação. Foram revistos 719 recordatórios alimentares de pacientes do grupo amamentado e 628 do grupo-controle. Foi realizada avaliação antropométrica no início e no final do estudo. A análise da ingestão de nutrientes foi feita com a utilização dos programas Minitab e LogXact 4.0, e a avaliação antropométrica foi feita com a utilização do programa Epi Info 6.0. RESULTADOS: O grupo amamentado apresentou ingestão adequada de fenilalanina e tirosina e maior adequação de ingestão proteica e energética. A maioria das crianças dos dois grupos apresentou escore-Z dentro dos limites normais (Z ³-2), com evolução favorável dos indicadores estudados (peso/idade, estatura/idade, peso/estatura e perímetro cefálico). CONCLUSÃO: O aleitamento materno na fenilcetonúria proporcionou ingestão adequada de calorias, fenilalanina, tirosina e proteína. A chance de uma criança do grupo amamentado possuir recordatórios de 24h adequados de ingestão energética foi 10,64 vezes maior que a chance de uma criança do grupo-controle. Em relação à ingestão proteica a chance foi 5,34 vezes maior. O crescimento foi similar nos dois grupos.

OBJECTIVE: This study aimed to assess energy, phenylalanine, tyrosine and protein intakes of breastfed infants with phenylketonuria (breastfed group). METHODS: A retrospective/prospective cohort study was used to compare a group of 39 breastfed infants aged 6 months or less (breastfed group) with a control group being fed a special low-phenylalanine formula. The groups were paired by gender and breastfeeding duration. A total of 719 dietary recalls of the breastfed group and 628 of the control group was reviewed. Anthropometric assessment was done at baseline and end of study. Nutrient intakes were calculated by the software Minitab and LogXact 4.0 and anthropometric assessment was done by the software Epi Info 6.0. RESULTS: The breastfed group presented adequate intake of phenylalanine and tyrosine and more adequate protein and energy intakes than the other group. Most infants, regardless of group, presented z-scores within the normal range (Z ³-2), with good progression of the studied indicators (weight-for-age, height-for-age, weight-for-height and head circumference). CONCLUSION: Breastfeeding of infants with phenylketonuria provided adequate energy, phenylalanine, tyrosine and protein intakes. The likelihood of a child in the breastfeed group to present adequate energy intake was 10.64 times higher than that of a child in the control group. In relation to protein intake, the chance was 5.34 times higher. Both groups presented similar growth.

Fenilcetonúria e a dieta especial: um desafio para a manutenção do peso corporal / Special diet and phenylketonuria: a challenge of body weight maintenance

A fenilcetonúria (PKU), a mais frequente das doenças genético-metabólicas, pode ser encontrada em diversos grupos étnicos, com incidência estimada em 1/21.175 nascidos vivos no estado de Minas Gerais. O tratamento da PKU é dietético e caracterizado pela restrição de fenilalanina (phe) associada ao uso de um substituto proteico – mistura de L-aminoácidos ou hidrolisado proteico – isento ou com traços de phe. No aporte calórico da dieta dos fenilcetonúricos predominam alimentos ricos em carboidratos simples e gorduras. A dieta hipercalórica durante a infância e a adolescência pode conduzir a distúrbios como sobrepeso e obesidade. Estudos indicam, ainda, que crianças com PKU podem ser predispostas à obesidade por apresentarem modificações na composição corporal, levando a alterações no metabolismo basal. Nessa breve revisão são apresentados estudos que demonstram a associação entre fenilcetonúria e excesso de peso...

Phenylketonuria (PKU), the most frequent genetic metabolic diseases can be found invarious ethnic groups, with an estimated incidence of 1/21.175 births in the state of Minas Gerais. The treatment of PKU is dietetic and made by phenilalanina (phe) restriction associated with the use of a protein substitute - a combination of L-amino acids or hydrolyzedprotein - free or with traces of phe. Calorie intake from the diet in PKU is complementedby foods rich in simple carbohydrates and fats. The high calorie diet during childhood and adolescence may lead to disorders like overweight and obesity. Studies also indicatethat children with PKU may be predisposed to obesity because they have changes in bodycomposition, leading to changes in basal metabolism. In this brief review we discussstudies that demonstrate the association between overweight and phenylketonuria...

Alterações auditivas e fenilcetonúria: uma revisão sistemática / Hearing disorders and phenylketonuria: a systematic review

TEMA: a fenilcetonúria é uma doença genética que provoca alterações bioquímicas conduzindo a uma deficiência na síntese de proteínas e de neurotransmissores, e prejudicando o processo de mielinização. Mudanças estruturais e funcionais da mielina podem alterar os padrões de condutividade neuronal e ou diminuir a conexão sináptica em indivíduos com fenilcetonúria. Essencialmente, um tratamento dietético deve ser realizado dentro das primeiras semanas de vida para evitar as manifestações clínicas e bioquímicas da doença. Quando a dieta é mantida ininterruptamente, as crianças com fenilcetonúria apresentam desenvolvimento normal. Porém, foram observados déficits em funções executivas, na interação inter-hemisférica, na linguagem e memória mesmo em crianças com tratamento precoce e dieta adequada. Algumas pesquisas foram realizadas para investigação da relação entre fenilcetonúria e alterações auditivas. OBJETIVO: rever de forma sistemática os artigos científicos dedicados à pesquisa da relação entre alterações auditivas e hiperfenilalaninemias, destacando a fenilcetonúria clássica. As referências bibliográficas foram obtidas por meio de pesquisa nas bases de dados Lilacs, Medline, Biblioteca Cochrane e Scielo e por busca na lista de referência dos artigos identificados e selecionados. CONCLUSÃO: conclui-se que a relação entre hiperfenilalaninemias, incluindo a fenilcetonúria, e alterações auditivas ainda é controversa na literatura. Sugere-se a realização de mais investigações sobre a função auditiva nesses indivíduos a fim de elucidar essa possível relação.

BACKGROUND: phenylketonuria is a genetic disorder that causes biochemical alterations, leading to a deficiency in the synthesis of proteins and neurotransmitters and thereby hindering the myelination process. Structural and functional changes in myelin can alter neural conductivity patterns and or reduce synaptic connection in individuals with phenylketonuria. Essentially, a dietary treatment should be implemented in the first weeks of life in order to avoid clinical and biochemical manifestations of the disease. When diet is continually maintained, children with phenylketonuria show normal development. However, deficits in executive functions, interhemispherical interaction, language and memory have been observed even in children with early treatment and appropriate diet. Some researches were carried out for investigating the relationship between phenylketonuria and alterations in the hearing function. PURPOSE: to systematically review articles dedicated to the research of relationship between hearing disorders and hyperphenylalaninaemias, highlighting the classic phenylketonuria. The bibliographical references were obtained through research in the databases: Lilacs, Medline, Cochrane Library and Scielo and through search in the reference list of the identified and selected articles. CONCLUSION: the relationship among hyperphenylalaninaemias, including phenylketonuria, and hearing alterations is still controversial in the literature. It is suggested that more investigations as for the hearing function are necessary on those individuals in order to elucidate this possible relationship.

Achados audiológicos em crianças com fenilcetonúria / Audiologic findings in children with phenylketonuria

OBJETIVO: Investigar a existência de alterações na audição de crianças com fenilcetonúria diagnosticadas e tratadas precocemente e comparar os resultados com os encontrados nas avaliações auditivas de crianças normais de mesma idade. MÉTODOS: Foram realizadas imitanciometria e audiometria tonal e vocal em 63 crianças, sendo 30 no grupo controle, com média de idade de 8,1 anos, e 33 com fenilcetonúria no grupo de estudo, com média de idade de 7,7 anos. O grupo de estudo foi subdividido em 15 crianças com controle adequado da dieta e 18 crianças com controle inadequado da dieta, com médias de idade 8,1 e 7,2, respectivamente. A análise estatística utilizou o Teste t ou ANOVA. RESULTADOS: A audiometria revelou 83,3 por cento de crianças com audição normal no grupo controle e 16,7 por cento de perdas auditivas condutivas uni ou bilaterais. No grupo com fenilcetonúria, 66,7 por cento das crianças apresentaram audição normal e 33,3 por cento com perdas auditivas condutivas. Na imitanciometria, observou-se curvas normais em 91,7 por cento das crianças do grupo controle e em 72,7 por cento das crianças do grupo com fenilcetonúria. Houve diferença na comparação entre grupos para limiares aéreos, reflexos estapedianos, limiares de recepção da fala e índice de reconhecimento de fala. Não foi observada diferença entre os resultados das avaliações auditivas de crianças fenilcetonúricas com dieta adequada e inadequada. CONCLUSÃO: As crianças com fenilcetonúria diagnosticadas e tratadas precocemente apresentaram piores limiares de audibilidade por via aérea, limiares de recepção de fala e índice de reconhecimento de fala evidenciados à audiometria tonal e vocal, quando comparadas com crianças normais.

PURPOSE: To investigate the existence of hearing impairments in infants with phenylketonuria with early diagnose and treatment, and to compare the audiological findings with those of their normal peers. METHODS: Vocal and pure-tone audiometry and acoustic immitance tests were conducted in 63 children, 30 from a control group, with mean age of 8.1 years, and 33 from a study group, with phenylketonuria and mean age of 7.7 years. The study group was subdivided according to diet control: 15 subjects had adequate (mean age of 8.1 years) and 18 had inadequate diet control (mean age 7.2 years). Statistical analysis used t-test or ANOVA. RESULTS: Audiometry showed that, in the control group, 83.3 percent of the subjects had normal hearing, and 16.7 percent had uni- or bilateral conductive hearing loss. In the study group, 66.7 percent of the subjects presented normal hearing, and 33.3 percent had conductive hearing loss. Immitance measures showed normal results in 91.7 percent of the children from the control group, and in 72.7 percent of the subjects with phenylketonuria. Differences were found between the groups regarding hearing thresholds, acoustic reflexes, speech reception thresholds, and speech recognition. No differences were observed between the results of phenylketonuria subjects with adequate and inadequate diets. CONCLUSION: Children with phenylketonuria early diagnosed and treated presented worse conductive hearing thresholds, speech reception threshold and speech recognition when compared to their normal peers, as evidenced in pure-tone and vocal audiometry.

Ação de fatores enzimáticos na obtenção de hidrolisados protéicos de farinha de trigo com baixo teor de fenilalanina / Action of enzymatic factors in obtaining protein hydrolysates of wheat flour, low-phenylalanine

Visando ao preparo de farinha de trigo com baixo teor de fenilalanina (Phe), extraiu-se, enzimaticamente as proteínas, empregando-se uma protease alcalina de Bacillus licheniformis. Em seguida, os extratos protéicos foram hidrolisados pela ação de enzimas comerciais (pancreatina e bromelina) e de extratos enzimáticos obtidos da casca de abacaxi (bruto e purificado), avaliando-se alguns parâmetros enzimáticos, tais como tipo de enzima, tipo de ação enzimática, tipo de associação enzimática e ordem de ação enzimática. O carvão ativado (CA) foi empregado como meio adsorvente e a eficiência da remoção de Phe foi avaliada por espectrofotometria derivada segunda, determinando-se o teor de Phe na farinha de trigo e em seus hidrolisados, após tratamento com CA. O melhor resultado foi encontrado ao se empregar a associação sucessiva do extrato bruto seguida da pancreatina, tendo atingido 66,28 por cento de remoção e o teor final de Phe de 522,44 mg/100 g de hidrolisado.

With the aim of producing wheat flour with low phenylalanine (Phe) content to be introduced in phenylketonuric's diet, the proteins were enzymaticaly extracted, using an alkaline protease from Bacillus licheniformis. Then, the protein extracts were hydrolyzed by the action of commercial enzymes (pancreatin and bromelain) and of enzymatic extracts obtained from pineapple peel (crude and purified). Some enzymatic parameters were evaluated, such as type of enzyme, type of enzyme action, type of enzymatic association and order of enzyme action. The activated carbon (AC) was used as adsorbent and the efficiency of Phe removal was evaluated by second derivative spectrophotometry measuring the Phe content in wheat flour and in their hydrolysates after AC treatment. The best result was found for the successive association of crude extract followed by pancreatin obtaining 66.28 percent of removal and a final Phe content of 522.44 mg/100 g of hydrolysate.

Frequencies of phenylalanine hydroxylase mutations I65T, R252W, R261Q, R261X, IVS10nt11, V388M, R408W, Y414C, and IVS12nt1 in Minas Gerais, Brazil.

In order to determine the phenylketonuria (PKU) mutation spectrum in the population of Minas Gerais State, Brazil, 78 unrelated PKU patients found by the neonatal screening program from 1993 to 2003 were tested for nine phenylalanine hydroxylase mutations. These mutations were selected due to their high frequencies in other Brazilian populations and in Portugal, where the largest contingent of the Caucasian component of the Brazilian population originated from. The most frequent mutations were V388M (21%), R261Q (16%), IVS10nt11 (13.4%), I65T (5.7%), and R252W (5%). The frequencies of the other four mutations (R261X, R408W, Y414C, and IVS12nt1) did not reach 2%. By testing these nine mutations, we were able to identify 64% of the PKU alleles in our sample. V388M frequency was higher than in any other known population and almost three times larger than that observed in Portugal, probably reflecting genetic drift. The mutation profile, as well as the relative frequency of the different mutations, suggest that the Minas Gerais population more closely resembles that of Portugal than do the other Brazilian populations that have already been tested.