Feeding difficulties in patients with Phenylketonuria. / Dificuldades alimentares em pacientes com Fenilcetonúria.

PURPOSE: to analyze the results of an instrument that aims to assist in the identification of feeding difficulties in children with Phenylketonuria (PKU), compared to children without the disease. METHODS: cross-sectional, controlled study with a convenience sample composed of patients with PKU and healthy individuals, matched for age and sex. The invitation to participate in the study was made through the dissemination of the research on social networks. The answers were provided by the guardians, 46 controls and 28 patients agreed to participate. In addition to these, 13 guardians of patients being followed up at an Outpatient Clinic for the Treatment of Inborn Errors of Metabolism were invited by phone call, and 12 accepted the invitation. All participants answered the Brazilian Infant Feeding Scale (in Portuguese Escala Brasileira de Alimentação Infantil (EBAI)) electronically. RESULTS: the study included 86 participants, 40 patients (median of age = 2 years; interquartile range (IQR) = 2 - 4) and 46 controls (median of age = 3.5 years; IQR = 2 - 5.25). Ten (25%) patients and 13 (28.3%) controls had suspicion of feeding difficulties, demonstrating a similar frequency of feeding difficulties between groups. The study found that PKU patients had less feed autonomy (p = 0.005), were less breastfed (p = 0.002) and used more baby's bottle than controls (p = 0.028). CONCLUSION: the frequency of feeding difficulties reported by caregivers was similar between the comparison groups, but children with PKU had less feed autonomy, were less breastfed and used more baby's bottles when compared to children without the disease.

OBJETIVO: analisar os resultados de um instrumento que se propõe a auxiliar na identificação das dificuldades alimentares em crianças com Fenilcetonúria (PKU), em comparação a crianças sem a doença. MÉTODO: estudo transversal, controlado, com amostra de conveniência composta por pacientes com PKU e por indivíduos hígidos, equiparados por idade e sexo. O convite para participação no estudo foi feito por meio de divulgação da pesquisa nas redes sociais. As respostas foram fornecidas pelos responsáveis, sendo que 46 controles e 28 pacientes participaram. Além desses, 13 responsáveis por pacientes em acompanhamento em um Ambulatório de Tratamento de Erros Inatos do Metabolismo foram convidados por ligação telefônica, sendo que 12 aceitaram o convite. Todos os participantes responderam a Escala Brasileira de Alimentação Infantil (EBAI) de forma eletrônica. RESULTADOS: foram incluídos no estudo 86 participantes, sendo 40 pacientes (mediana de idade, 2 anos; intervalo interquartil (IQR) = 2 - 4) e 46 controles (mediana de idade, 3,5 anos; IQR = 2 - 5,25). Dez (25%) pacientes e 13 (28,3%) controles apresentaram resultados compatíveis com dificuldades alimentares, demonstrando uma frequência semelhante entre os grupos. O estudo observou que os pacientes com PKU apresentaram menos autonomia alimentar (p = 0,005), foram menos amamentados (p = 0,002) e usaram mais mamadeira que os controles (p = 0,028). CONCLUSÃO: a frequência de dificuldades alimentares referidas pelos cuidadores foi semelhante entre os grupos, porém as crianças com PKU demonstraram menos autonomia para se alimentar, foram menos amamentadas e usaram mais mamadeira quando comparadas com as crianças sem a doença.

A Broad Characterization of Glycogen Storage Disease IV Patients: A Clinical, Genetic, and Histopathological Study.

Glycogen storage disease type IV (GSD IV) is an ultra-rare autosomal recessive disease caused by variants in the GBE1 gene, which encodes the glycogen branching enzyme (GBE). GSD IV accounts for approximately 3% of all GSD. The phenotype of GSD IV ranges from neonatal death to mild adult-onset disease with variable hepatic, muscular, neurologic, dermatologic, and cardiac involvement. There is a paucity of literature and clinical and dietary management in GSD IV, and liver transplantation (LT) is described to correct the primary hepatic enzyme defect. Objectives: We herein describe five cases of patients with GSD IV with different ages of onset and outcomes as well as a novel GBE1 variant. Methods: This is a descriptive case series of patients receiving care for GSD IV at Reference Centers for Rare Diseases in Brazil and in the United States of America. Patients were selected based on confirmatory GBE1 genotypes performed after strong clinical suspicion. Results: Pt #1 is a Latin male with the chief complaints of hepatosplenomegaly, failure to thrive, and elevated liver enzymes starting at the age of 5 months. Before LT at the age of two, empirical treatment with corn starch (CS) and high protein therapy was performed with subjective improvement in his overall disposition and liver size. Pt #2 is a 30-month-old Afro-American descent patient with the chief complaints of failure to gain adequate weight, hypotonia, and hepatosplenomegaly at the age of 15 months. Treatment with CS was initiated without overall improvement of the symptoms. Pt #3.1 is a female Latin patient, sister to pt #3.2, with onset of symptoms at the age of 3 months with bloody diarrhea, abdominal distention, and splenomegaly. There was no attempt of treatment with CS. Pt #4 is an 8-year-old male patient of European descent who had his initial evaluation at 12 months, which was remarkable for hepatosplenomegaly, elevated ALT and AST levels, and a moderate dilatation of the left ventricle with normal systolic function that improved after LT. Pt #1, #3.2 and #4 presented with high levels of chitotriosidase. Pt #2 was found to have the novel variant c.826G > C p.(Ala276Pro). Conclusions: GSD IV is a rare disease with different ages of presentation and different cardiac phenotypes, which is associated with high levels of chitotriosidase. Attempts of dietary intervention with CS did not show a clear improvement in our case series.

Dificuldades alimentares em pacientes com Fenilcetonúria / Feeding difficulties in patients with Phenylketonuria

RESUMO Objetivo analisar os resultados de um instrumento que se propõe a auxiliar na identificação das dificuldades alimentares em crianças com Fenilcetonúria (PKU), em comparação a crianças sem a doença. Método estudo transversal, controlado, com amostra de conveniência composta por pacientes com PKU e por indivíduos hígidos, equiparados por idade e sexo. O convite para participação no estudo foi feito por meio de divulgação da pesquisa nas redes sociais. As respostas foram fornecidas pelos responsáveis, sendo que 46 controles e 28 pacientes participaram. Além desses, 13 responsáveis por pacientes em acompanhamento em um Ambulatório de Tratamento de Erros Inatos do Metabolismo foram convidados por ligação telefônica, sendo que 12 aceitaram o convite. Todos os participantes responderam a Escala Brasileira de Alimentação Infantil (EBAI) de forma eletrônica. Resultados foram incluídos no estudo 86 participantes, sendo 40 pacientes (mediana de idade, 2 anos; intervalo interquartil (IQR) = 2 - 4) e 46 controles (mediana de idade, 3,5 anos; IQR = 2 - 5,25). Dez (25%) pacientes e 13 (28,3%) controles apresentaram resultados compatíveis com dificuldades alimentares, demonstrando uma frequência semelhante entre os grupos. O estudo observou que os pacientes com PKU apresentaram menos autonomia alimentar (p = 0,005), foram menos amamentados (p = 0,002) e usaram mais mamadeira que os controles (p = 0,028). Conclusão a frequência de dificuldades alimentares referidas pelos cuidadores foi semelhante entre os grupos, porém as crianças com PKU demonstraram menos autonomia para se alimentar, foram menos amamentadas e usaram mais mamadeira quando comparadas com as crianças sem a doença.

ABSTRACT Purpose to analyze the results of an instrument that aims to assist in the identification of feeding difficulties in children with Phenylketonuria (PKU), compared to children without the disease. Methods cross-sectional, controlled study with a convenience sample composed of patients with PKU and healthy individuals, matched for age and sex. The invitation to participate in the study was made through the dissemination of the research on social networks. The answers were provided by the guardians, 46 controls and 28 patients agreed to participate. In addition to these, 13 guardians of patients being followed up at an Outpatient Clinic for the Treatment of Inborn Errors of Metabolism were invited by phone call, and 12 accepted the invitation. All participants answered the Brazilian Infant Feeding Scale (in Portuguese Escala Brasileira de Alimentação Infantil (EBAI)) electronically. Results the study included 86 participants, 40 patients (median of age = 2 years; interquartile range (IQR) = 2 - 4) and 46 controls (median of age = 3.5 years; IQR = 2 - 5.25). Ten (25%) patients and 13 (28.3%) controls had suspicion of feeding difficulties, demonstrating a similar frequency of feeding difficulties between groups. The study found that PKU patients had less feed autonomy (p = 0.005), were less breastfed (p = 0.002) and used more baby's bottle than controls (p = 0.028). Conclusion the frequency of feeding difficulties reported by caregivers was similar between the comparison groups, but children with PKU had less feed autonomy, were less breastfed and used more baby's bottles when compared to children without the disease.

Current Practices and Challenges in the Diagnosis and Management of PKU in Latin America: A Multicenter Survey.

This study aimed to describe the current practices in the diagnosis and dietary management of phenylketonuria (PKU) in Latin America, as well as the main barriers to treatment. We developed a 44-item online survey aimed at health professionals. After a pilot test, the final version was sent to 25 practitioners working with inborn errors of metabolism (IEM) in 14 countries. Our results include 22 centers in 13 countries. Most countries (12/13) screened newborns for PKU. Phenylalanine (Phe) targets at different ages were very heterogeneous among centers, with greater consistency at the 0-1 year age group (14/22 sought 120-240 µmol/L) and the lowest at >12 years (10 targets reported). Most countries had only unflavored powdered amino acid substitutes (10/13) and did not have low-protein foods (8/13). Only 3/13 countries had regional databases of the Phe content of foods, and only 4/22 centers had nutrient analysis software. The perceived obstacles to treatment were: low purchasing power (62%), limited/insufficient availability of low-protein foods (60%), poor adherence, and lack of technical resources to manage the diet (50% each). We observed a heterogeneous scenario in the dietary management of PKU, and most countries experienced a lack of dietary resources for both patients and health professionals.

Description of a Nutrition Screening and Assessment Tool and Associations with Clinical Outcomes in Preterm Newborns.

BACKGROUND: Preterm newborns have higher nutrition risk and mortality. Nutrition risk screening enables early intervention. This article evaluates a nutrition screening tool in a neonatal intensive care unit (NICU). METHOD: Retrospective longitudinal study of preterm newborns (aged <37 weeks) in a NICU in Brazil from May 2018 to January 2019. Weight, length, and head circumference (HC) were analyzed. Nutrition screening was defined by care levels (CLs). Outcomes analyzed were bronchopulmonary dysplasia (BPD), peri-intraventricular hemorrhage (PIVH), retinopathy of prematurity (ROP), late sepsis, length of stay, mortality, and time receiving enteral and parenteral nutrition. RESULTS: Data on 110 newborns were studied, with median gestational age 34 (31-35) weeks, mean weight 1914.92 g (±657.7), length 42.2 cm (±4.45), and HC 29.9 cm (±2.97). Most (82.7%) of them were adequate for gestational age. Screening classifications were 41.8% (n = 46) at CL 2, 41.8% (n = 46) at CL 3, and 16.4% (n = 18) at CL 4. CL 3 and CL 4 patients had higher frequencies of BPD (P = .003), ROP (P = .027), and PIVH (P = .006) and longer enteral time (P < .001) and length of stay (P < .001). All mortality occurred in CL 4 patients (P < .001). CONCLUSIONS: CL 3 and CL 4 patients had more BPD, ROP, PIVH, and mortality and longer enteral nutrition. Hospital stay was longer for CL ≥3 than CL 2 patients. Patients classified as CL 3 and CL 4 by the nutrition screening tool may have higher nutrition risk.

Feeding Difficulties and Orofacial Myofunctional Disorder in Patients with Hepatic Glycogen Storage Diseases.

Hepatic glycogen storage diseases (GSDs) are inborn errors of metabolism whose dietary treatment involves uncooked cornstarch administration and restriction of simple carbohydrate intake. The prevalence of feeding difficulties (FDs) and orofacial myofunctional disorders (OMDs) in these patients is unknown. OBJECTIVE: To ascertain the prevalence of FDs and OMDs in GSD. METHODS: This was a cross-sectional, prospective study of 36 patients (19 males; median age, 12.0 years; range, 8.0-18.7 years) with confirmed diagnoses of GSD (type Ia = 22; Ib = 8; III = 2; IXa = 3; IXc = 1). All patients were being treated by medical geneticists and dietitians. Evaluation included a questionnaire for evaluation of feeding behavior, the orofacial myofunctional evaluation (AMIOFE), olfactory and taste performance (Sniffin' Sticks and Taste Strips tests), and facial anthropometry. RESULTS: Nine (25%) patients had decreased olfactory perception, and four (11%) had decreased taste perception for all flavours. Eight patients (22.2%) had decreased perception for sour taste. Twenty-six patients (72.2%) had FD, and 18 (50%) had OMD. OMD was significantly associated with FD, tube feeding, selective intake, preference for fluid and semisolid foods, and mealtime stress (p < 0.05). Thirteen patients (36.1%) exhibited mouth or oronasal breathing, which was significantly associated with selective intake (p = 0.011) and not eating together with the rest of the family (p = 0.041). Lower swallowing and chewing scores were associated with FD and with specific issues related to eating behavior (p < 0.05). CONCLUSION: There is a high prevalence of FDs and OMDs in patients with GSD. Eating behavior, decreased taste and smell perception, and orofacial myofunctional issues are associated with GSD.

Análise da densidade mineral óssea em pacientes com fenilcetonúria e sua correlação com parâmetros nutricionais / Bone mineral density assessment in patients with phenylketonuria and its correlation with nutritional parameters

Introdução: Redução da densidade mineral óssea (DMO) está associada à Fenilcetonúria (PKU), mas a causa desta associação não é completamente entendida. O objetivo desse estudo foi avaliar a ingestão de nutrientes relacionados ao metabolismo ósseo (cálcio, fósforo, magnésio, potássio), e sua associação com a DMO em pacientes com PKU. Métodos: Estudo transversal, observacional. Foram incluídos 15 pacientes (PKU Clássica=8; Leve=7; mediana de idade=16 anos, IQ=15-20), todos em tratamento com dieta restrita em fenilalanina (Phe) e 13 em uso de fórmula metabólica. Foi realizado recordatório alimentar de 24 horas de um dia e demais dados (histórico de fraturas, parâmetros antropométricos, DMO e níveis plasmáticos de Phe, Tyr, cálcio) foram obtidos por revisão de prontuário. Resultados: Nenhum paciente apresentou histórico de fraturas e seis realizavam suplementação de cálcio (alteração prévia da DMO=5; baixa ingestão=1). A mediana dos níveis de Phe foi 11,6 mg/dL (IQ=9,3-13,3). Em relação ao recordatório alimentar, dez indivíduos apresentaram inadequado consumo de carboidratos; 14, de lipídeos; 9, de cálcio; 11, de magnésio; 13, de fósforo; e todos de potássio. A mediana da DMO foi de 0,989 g/cm2 (IQ=0,903-1,069), sendo duas classificadas como reduzidas para idade, ambas de pacientes com PKU Leve que recebiam suplementação de cálcio. Não foi observada correlação entre níveis de Phe, DMO e demais variáveis analisadas. Conclusão: Redução da DMO não foi frequente na amostra, embora ingestão inadequada de cálcio assim o seja. Estudos adicionais são necessários para esclarecer o efeito da Phe e da ingestão dietética sobre o metabolismo ósseo na PKU. (AU)

Introduction: Reduced bone mineral density (BMD) is associated with phenylketonuria (PKU), but this association is not completely understood. This research aimed to evaluate intake of nutrients related to bone metabolism (calcium, phosphorus, magnesium, potassium) and its association with BMD in patients with PKU. Methods: In this cross-sectional, observational study, 15 patients with PKU (Classical=8, Mild=7; median age=16 years, IQ=15-20 years) were included, all of them on phenylalanine (Phe) restricted diet and 13 being supplemented with a metabolic formula. A 24-hour dietary recall was performed and remaining data (history of fractures, anthropometric parameters, BMD and plasma Phe, tyrosine and calcium levels) were obtained through medical chart review. Results: No patient had any fractures and six received calcium supplements, five due to previous change in BMD and one due to inadequate nutritional intake. Median Phe level was 11.6 mg/dL (IQ=9.3-13.3). In relation to dietary recall, all individuals had inadequate intake of some nutrient (carbohydrate=10; lipids=14; calcium=9; magnesium=11; phosphorus=13; potassium=15). The median BMD was 0.989 g/cm2 (IQ=0.903-1.069). Two cases were classified as low BMD for age, both in patients with mild PKU receiving calcium supplements. Conclusion: Reduced BMD was not common in this sample, although inadequate calcium intake was frequently reported. Additional studies are needed to clarify the effect of Phe and dietary intake on bone metabolism in patients with PKU.(AU)

Phenylketonuria and Gut Microbiota: A Controlled Study Based on Next-Generation Sequencing.

Phenylketonuria (PKU) is an inborn error of metabolism associated with high blood levels of phenylalanine (Phe). A Phe-restricted diet supplemented with L-amino acids is the main treatment strategy for this disease; if started early, most neurological abnormalities can be prevented. The healthy human gut contains trillions of commensal bacteria, often referred to as the gut microbiota. The composition of the gut microbiota is known to be modulated by environmental factors, including diet. In this study, we compared the gut microbiota of 8 PKU patients on Phe-restricted dietary treatment with that of 10 healthy individuals. The microbiota were characterized by 16S rRNA sequencing using the Ion Torrent™ platform. The most dominant phyla detected in both groups were Bacteroidetes and Firmicutes. PKU patients showed reduced abundance of the Clostridiaceae, Erysipelotrichaceae, and Lachnospiraceae families, Clostridiales class, Coprococcus, Dorea, Lachnospira, Odoribacter, Ruminococcus and Veillonella genera, and enrichment of Prevotella, Akkermansia, and Peptostreptococcaceae. Microbial function prediction suggested significant differences in starch/glucose and amino acid metabolism between PKU patients and controls. Together, our results suggest the presence of distinct taxonomic groups within the gut microbiome of PKU patients, which may be modulated by their plasma Phe concentration. Whether our findings represent an effect of the disease itself, or a consequence of the modified diet is unclear.

Fenilcetonúria no sistema único de saúde: avaliação de adesão ao tratamento em um centro de atendimento do Rio Grande do Sul / Phenylketonuria in the public health system: assessment of adherence to treatment in a medical care center in Rio Grande do Sul

Introdução: Fenilcetonúria (PKU) é um erro inato do metabolismo no qual ocorre um aumento dos níveis séricos do aminoácido fenilalanina. Objetivo: O presente estudo teve como objetivo avaliar a adesão ao tratamento de pacientes com PKU atendidos em um centro de referência do Rio Grande do Sul. Métodos: Estudo transversal de pacientes com PKU atendidos no ambulatório do Serviço de Genética Médica do Hospital de Clínicas de Porto Alegre, Brasil. Os parâmetros de adesão considerados foram a mediana de fenilalanina plasmática no último ano (critério 1); o consumo de fenilalanina (critério 2); o consumo de fórmula metabólica (critério 3); e o questionamento direto aos pacientes/familiares (critério 4). Resultados: Dos 45 pacientes incluídos no estudo, (mediana de idade de 11 anos), 51% eram do sexo masculino. De acordo com o critério utilizado, foram considerados aderentes 20 (critério 1); 16 (critério 2); 27 (critério 3) e 33 (critério 4) pacientes, respectivamente. Não houve concordância entre os critérios de adesão utilizados. Foram encontradas diferenças quando comparados os critérios 1 e 2 (P=0,027), critérios 1 e 3 (P=0,002) e critérios 3 e 4 (P=0,015). Conclusão: A adesão ao tratamento é dificilmente quantificada por parâmetros isolados. A distinta percepção por parte dos pacientes dá suporte à necessidade de busca de novas estratégias que promovam adesão, bem como do estudo de métodos que avaliem a mesma.

Introduction: Phenylketonuria (PKU) is an inborn error of metabolism in which there is an increase in the serum amino acid phenylalanine. Aim:This study aimed at evaluating the adherence to treatment of patients with PKU treated at a center of reference in Rio Grande do Sul. Methods: A cross-sectional study of PKU patients seen at the outpatient clinic of the Medical Genetics Service, Hospital de Clínicas de Porto Alegre, Brazil. The parameters considered for adherence were: median of plasma phenylalanine in the past year (criterion 1); consumption of phenylalanine (criterion 2); consumption of metabolic formula (criterion 3); and direct questioning of patients/families (criterion 4). Results: Of the 45 patients included in the study (median age of 11 years), 51% were male. According to the criteria used, the following number of patients were considered compliant: 20 (criterion 1); 16 (criterion 2); 27 (criterion 3); and 33 (criterion 4), respectively. There was no agreement among the adherence criteria used. Differences were found when comparing criteria 1 and 2 (P=0.027), criteria 1 and 3 (P=0.002), and criteria 3 and 4 (P=0.015). Conclusion: Adherence to treatment is barely quantified by isolated parameters. The patients’ different perception support the need of searching for new strategies to promote adherence and also new methods of assessment.

Molecular characterization of phenylketonuria in South Brazil.

Phenylketonuria (PKU) is an autosomal recessive disorder due to phenylalanine hydroxylase (PAH) deficiency. The PAH gene, located at 12q22-q24.1, includes about 90kb and contains 13 exons. To date, more than 420 different alterations have been identified in the PAH gene. To determine the nature and frequency of PAH mutations in PKU patients from South Brazil, mutation analysis was performed on genomic DNA from 23 unrelated PKU patients. The 13 exons and flanking regions of the PAH gene were amplified by PCR and the amplicons were analyzed by single strand conformation polymorphism (SSCP). Amplicons that showed abnormal migration patterns were analyzed by restriction endonuclease digestion and/or sequencing. Twenty-two previously reported mutations were identified including R261X, R408W, IVS2nt5g-->c, R261Q, and V388M. Polymorphisms were observed in 48.8% of the PKU patients, the most frequent being IVS2nt19t-->c, V245V, and IVS12nt-35c-->t. In addition, two novel sequence variants were identified: 1378g-->t in the 3(')-untranslated region in exon 13 which may be disease-causing and an intron 12 polymorphism, IVS12nt-15t-->c. The mutation spectrum in the patients from Southern Brazil differed from that observed in patients from other Latin American countries and further defined the molecular heterogeneity of this disease.