Homocysteine and methylmalonic acid in Phenylketonuria patients.

Hyperhomocysteinemia and vitamin B12 deficiency have been reported in patients with phenylketonuria. In this study, total homocysteine (tHcy) and methylmalonic acid (MMA) levels were analyzed in samples from 25 phenylketonuria (PKU) patients. Comparisons were made between pre- and post-treatment values (n= 3); on treatment values, between periods with high and normal/low phenylalanine (Phe) levels (n= 20); and in women before, during and after pregnancy (n= 3). THcy levels decreased after treating PKU with metabolic formula (p=0.014). Except for a pregnant woman before pregnancy, none of the patients had tHcy values above the normal range. In fact, tHcy was < 5 µmol/L in 34% of the samples. We observed a decrease in Phe, tHcy, and tyrosine levels during pregnancy. MMA levels did not differ significantly, with values remaining in the normal range. These data indicate that there was no B12 deficiency in patients who adhere to the diet. In conclusion, in PKU patients treated with metabolic formula, tHcy is frequently not elevated, remaining even in the lower normal range in some patients. Thus, clinical follow-up and adherence to dietary treatment are crucial to prevent B12 deficiency.

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.

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.

Brazilian Food Reference Guide for Phenylalanine Content: A Study Based on the Perception of PKU Patients and Health Providers

Abstract The mainstay of management of phenylketonuria (PKU) is restriction of dietary phenylalanine (Phe) intake. The present study sought to assess the perception and understanding of health care providers and lay users (patients/family members/caregivers) regarding the national reference database for checking the Phe content of foods, provided by the Brazilian Health Regulatory Agency (Anvisa), whose data are presented in the Table of Phenylalanine Content of Foods (TCFA-Anvisa) and recently in the Phenylalanine Content of Foods Dashboard (PCCFA-Anvisa); and to identify factors which interfere with the usability of these resources. Two online questionnaires, one for providers (n=33) and another for lay users (n=194), were used to collect sociodemographic information, knowledge about dietary management of PKU, sources of information about the Phe content of foods, and perception and understanding of the Anvisa tools. TCFA-Anvisa and PCCFA-Anvisa were not used as main sources of information by either group. Among the participants who had used these tools (15 providers;35 lay users), most considered the PCCFA-Anvisa to be superior or partially superior to the TCFA-Anvisa. The main limitations reported were related to layout and limited variety of foods. We suggest that the limitations identified in this study be considered for future improvement of these resources.

Phenylketonuria Diagnosis by Massive Parallel Sequencing and Genotype-Phenotype Association in Brazilian Patients.

Phenylketonuria (PKU) is a common inborn error of amino acid metabolism in which the enzyme phenylalanine hydroxylase, which converts phenylalanine to tyrosine, is functionally impaired due to pathogenic variants in the PAH gene. Thirty-four Brazilian patients with a biochemical diagnosis of PKU, from 33 unrelated families, were analyzed through next-generation sequencing in the Ion Torrent PGM™ platform. Phenotype-genotype correlations were made based on the BioPKU database. Three patients required additional Sanger sequencing analyses. Twenty-six different pathogenic variants were identified. The most frequent variants were c.1315+1G>A (n = 8/66), c.473G>A (n = 6/66), and c.1162G>A (n = 6/66). One novel variant, c.524C>G (p.Pro175Arg), was found in one allele and was predicted as likely pathogenic by the American College of Medical Genetics and Genomics (ACMG) criteria. The molecular modeling of p.Pro175Arg indicated that this substitution can affect monomers binding in the PAH tetramer, which could lead to a change in the stability and activity of this enzyme. Next-generation sequencing was a fast and effective method for diagnosing PKU and is useful for patient phenotype prediction and genetic counseling.

Maple syrup urine disease in Brazilian patients: variants and clinical phenotype heterogeneity.

BACKGROUND: Maple syrup urine disease (MSUD) is an autosomal recessive inherited metabolic disease caused by deficient activity of the branched-chain α-keto acid dehydrogenase (BCKD) enzymatic complex. BCKD is a mitochondrial complex encoded by BCKDHA, BCKDHB, DBT, and DLD genes. MSUD is predominantly caused by Variants in BCKDHA, BCKDHB, and DBT genes encoding the E1α, E1ß, and E2 subunits of BCKD complex, respectively. The aim of this study was to characterize the genetic basis of MSUD by identifying the point variants in BCKDHA, BCKDHB, and DBT genes in a cohort of Brazilian MSUD patients and to describe their phenotypic heterogeneity. It is a descriptive cross-sectional study with 21 MSUD patients involving molecular genotyping by Sanger sequencing. RESULTS: Eight new variants predicted as pathogenic were found between 30 variants (damaging and non-damaging) identified in the 21 patients analyzed: one in the BCKDHA gene (p.Tyr120Ter); five in the BCKDHB gene (p.Gly131Val, p.Glu146Glnfs * 13, p.Phe149Cysfs * 9, p.Cys207Phe, and p.Lys211Asn); and two in the DBT gene (p.Glu148Ter and p.Glu417Val). Seventeen pathogenic variants were previously described and five variants showed no pathogenicity according to in silico analysis. CONCLUSION: Given that most of the patients received late diagnoses, the study results do not allow us to state that the molecular features of MSUD variant phenotypes are predictive of clinical severity.

Domino Liver Transplant in Maple Syrup Urine Disease: Technical Details of Cases in Which the First Surgery Involved a Living Donor.

BACKGROUND: Data describing the technical aspects of living donor (LD) domino liver transplantation (DLT) in maple syrup urine disease (MSUD) are limited. The largest published series includes only 3 cases. One great challenge of this procedure is to ensure adequate vascular stumps for the LD, the MSUD patient, and the recipient of the domino graft. Here, we describe our experience in 11 cases of LD-DLT in MSUD, highlighting the technical aspects of LD-DLT. METHODS: From September 2012 to September 2017, 11 patients with MSUD underwent LD liver transplantation at our institution, and MSUD livers were used as domino grafts in 11 children. RESULTS: (1) MSUD patients: 10 patients received a left lateral segment. The donor's left hepatic vein (HV) was anastomosed to the confluence of the recipient's 3 HVs. No vascular grafts (VG) were required for portal vein (PV) anastomosis. Single arterial anastomosis was performed with microsurgery in 10 of 11 patients. (2) MSUD graft recipients: In 8 cases, HV reconstruction was performed between the graft's HV confluence and the recipient's HV confluence, and in 3 cases, a vena cava triangulation was necessary; 6 MSUD grafts required HV venoplasty. No VG were needed for HV reconstruction. VG were used for PV reconstruction in 3 cases due to sclerotic PV. In 2 cases, double arterial anastomoses were performed in the MSUD liver. All patients remain alive and well. CONCLUSIONS: Living donor liver transplantation followed by DLT for MSUD is a complex procedure and demands technical refinement. Special attention must be paid to vascular reconstruction.

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.

Evaluation of plasma biomarkers of inflammation in patients with maple syrup urine disease.

Maple syrup urine disease (MSUD) is an autosomal recessive inherited disorder that affects branched-chain amino acid (BCAA) catabolism and is associated with acute and chronic brain dysfunction. Recent studies have shown that inflammation may be involved in the neuropathology of MSUD. However, these studies have mainly focused on single or small subsets of proteins or molecules. Here we performed a case-control study, including 12 treated-MSUD patients, in order to investigate the plasmatic biomarkers of inflammation, to help to establish a possible relationship between these biomarkers and the disease. Our results showed that MSUD patients in treatment with restricted protein diets have high levels of pro-inflammatory cytokines [IFN-γ, TNF-α, IL-1ß and IL-6] and cell adhesion molecules [sICAM-1 and sVCAM-1] compared to the control group. However, no significant alterations were found in the levels of IL-2, IL-4, IL-5, IL-7, IL-8, and IL-10 between healthy controls and MSUD patients. Moreover, we found a positive correlation between number of metabolic crisis and IL-1ß levels and sICAM-1 in MSUD patients. In conclusion, our findings in plasma of patients with MSUD suggest that inflammation may play an important role in the pathogenesis of MSUD, although this process is not directly associated with BCAA blood levels. Overall, data reported here are consistent with the working hypothesis that inflammation may be involved in the pathophysiological mechanism underlying the brain damage observed in MSUD patients.

Assessment of newborn screening in the public health system of a municipality in northern Rio Grande do Sul

Introduction: Newborn screening allows the screening of diseases that are still in the asymptomatic period and whose early diagnosis and treatment are associated with reduced infant morbidity and mortality. The aim of this study was to evaluate the public National Newborn Screening Program in the municipality of Carazinho, state of Rio Grande do Sul (RS), Brazil. Methods: This was a population-based, retrospective, descriptive study. We collected and transcribed data from a database of the Carazinho municipal laboratory, which is affiliated with the referral center for newborn screening in RS. The records of all individuals undergoing newborn screening from 2005 to 2010 were reviewed, and information was collected on the program coverage, time elapsed between birth and screening (first collection), and test results. Results: The program had a coverage of 75.5%. One suspected case of phenylketonuria, three suspected cases of congenital hypothyroidism and no suspected cases of hemoglobinopathy were identified. In addition, there were 18 positive results for hemoglobin S heterozygosity, five for hemoglobin D heterozygosity, two for hemoglobin C heterozygosity, and one for a rare variant hemoglobin. When analyzing the newborn's age at the time of blood collection, it was observed that 63.1% were within the recommended age range. Conclusions: Our findings suggest the need for optimization of public newborn screening in the evaluated municipality. The strategies to be adopted should include education of the population and especially of managers and health professionals about the importance of newborn screening. (AU)

Serum Markers of Neurodegeneration in Maple Syrup Urine Disease.

Maple syrup urine disease (MSUD) is an inherited disorder caused by deficient activity of the branched-chain α-keto acid dehydrogenase complex involved in the degradation pathway of branched-chain amino acids (BCAAs) and their respective α-keto-acids. Patients affected by MSUD present severe neurological symptoms and brain abnormalities, whose pathophysiology is poorly known. However, preclinical studies have suggested alterations in markers involved with neurodegeneration. Because there are no studies in the literature that report the neurodegenerative markers in MSUD patients, the present study evaluated neurodegenerative markers (brain-derived neurotrophic factor (BDNF), cathepsin D, neural cell adhesion molecule (NCAM), plasminogen activator inhibitor-1 total (PAI-1 (total)), platelet-derived growth factor AA (PDGF-AA), PDGF-AB/BB) in plasma from 10 MSUD patients during dietary treatment. Our results showed a significant decrease in BDNF and PDGF-AA levels in MSUD patients. On the other hand, NCAM and cathepsin D levels were significantly greater in MSUD patients compared to the control group, while no significant changes were observed in the levels of PAI-1 (total) and PDGF-AB/BB between the control and MSUD groups. Our data show that MSUD patients present alterations in proteins involved in the neurodegenerative process. Thus, the present findings corroborate previous studies that demonstrated that neurotrophic factors and lysosomal proteases may contribute, along with other mechanisms, to the intellectual deficit and neurodegeneration observed in MSUD.

Access to treatment for phenylketonuria by judicial means in Rio Grande do Sul, Brazil.

Treatment of phenylketonuria (PKU) includes the use of a metabolic formula which should be provided free of charge by the Unified Health System (SUS). This retrospective, observational study sought to characterize judicial channels to obtain PKU treatment in Rio Grande do Sul (RS), Brazil. Lawsuits filed between 2001- 2010 and having as beneficiaries PKU patients requesting treatment for the disease were included. Of 20 lawsuits filed, corresponding to 16.8% of RS patients with PKU, 19 were retrieved for analysis. Of these, only two sought to obtain therapies other than metabolic formula. In all the other 17 cases, prior treatment requests had been granted by the State Department of Health. Defendants included the State (n = 19), the Union (n = 1), and municipalities (n = 4). In 18/19 cases, the courts ruled in favor of the plaintiffs. Violation of the right to health and discontinuation of State-provided treatment were the main reasons for judicial recourse. Unlike other genetic diseases, patients with PKU seek legal remedy to obtain a product already covered by the national pharmaceutical assistance policy, suggesting that management failures are a driving factor for judicialization in Brazil.

Access to treatment for phenylketonuria by judicial means in Rio Grande do Sul, Brazil / Acesso ao tratamento para fenilcetonúria por via judicial no Rio Grande do Sul, Brasil

Treatment of phenylketonuria (PKU) includes the use of a metabolic formula which should be provided free of charge by the Unified Health System (SUS). This retrospective, observational study sought to characterize judicial channels to obtain PKU treatment in Rio Grande do Sul (RS), Brazil. Lawsuits filed between 2001- 2010 and having as beneficiaries PKU patients requesting treatment for the disease were included. Of 20 lawsuits filed, corresponding to 16.8% of RS patients with PKU, 19 were retrieved for analysis. Of these, only two sought to obtain therapies other than metabolic formula. In all the other 17 cases, prior treatment requests had been granted by the State Department of Health. Defendants included the State (n = 19), the Union (n = 1), and municipalities (n = 4). In 18/19 cases, the courts ruled in favor of the plaintiffs. Violation of the right to health and discontinuation of State-provided treatment were the main reasons for judicial recourse. Unlike other genetic diseases, patients with PKU seek legal remedy to obtain a product already covered by the national pharmaceutical assistance policy, suggesting that management failures are a driving factor for judicialization in Brazil.

O tratamento da fenilcetonúria (PKU) inclui o uso de uma fórmula metabólica (FM) fornecida sem custos pelo Sistema Único de Saúde (SUS). O objetivo do estudo foi caracterizar o uso da via judicial para obter tratamento para PKU no estado do Rio Grande do Sul (RS), Brasil, através de um estudo retrospectivo e observacional, analisando ações judiciais. Foram incluídas ações judiciais arquivadas entre 2001-2010 que possuíam como beneficiários indivíduos com PKU solicitando alguma forma de tratamento para PKU. Foram localizados 20 casos, correspondendo a 16,8% dos pacientes com PKU no RS, sendo 19 obtidos para análise. Somente dois procuravam obter outras terapias que a FM. Nos outros 17 casos, uma solicitação de tratamento anterior fora concedida pela Secretaria Estadual de Saúde. Os réus incluem o Estado (n = 19), União (n = 1) e municípios (n = 4). Em 18/19 casos, os tribunais decidiram a favor dos demandantes. Violação do direito à saúde e interrupção do tratamento prestado pelo Estado foram os principais motivos para recorrer aos tribunais. Diferente de outras doenças genéticas, os pacientes com PKU buscam o meio jurídico para obter um produto já incluso na política de assistência farmacêutica nacional, sugerindo que falhas de gestão são um dos fatores desencadeantes da judicialização no país.

Body composition in patients with classical homocystinuria: body mass relates to homocysteine and choline metabolism.

INTRODUCTION: Classical homocystinuria is a rare genetic disease caused by cystathionine ß-synthase deficiency, resulting in homocysteine accumulation. Growing evidence suggests that reduced fat mass in patients with classical homocystinuria may be associated with alterations in choline and homocysteine pathways. This study aimed to evaluate the body composition of patients with classical homocystinuria, identifying changes in body fat percentage and correlating findings with biochemical markers of homocysteine and choline pathways, lipoprotein levels and bone mineral density (BMD) T-scores. METHODS: Nine patients with classical homocystinuria were included in the study. Levels of homocysteine, methionine, cysteine, choline, betaine, dimethylglycine and ethanolamine were determined. Body composition was assessed by bioelectrical impedance analysis (BIA) in patients and in 18 controls. Data on the last BMD measurement and lipoprotein profile were obtained from medical records. RESULTS: Of 9 patients, 4 (44%) had a low body fat percentage, but no statistically significant differences were found between patients and controls. Homocysteine and methionine levels were negatively correlated with body mass index (BMI), while cysteine showed a positive correlation with BMI (p<0.05). There was a trend between total choline levels and body fat percentage (r=0.439, p=0.07). HDL cholesterol correlated with choline and ethanolamine levels (r=0.757, p=0.049; r=0.847, p=0.016, respectively), and total cholesterol also correlated with choline levels (r=0.775, p=0.041). There was no association between BMD T-scores and body composition. CONCLUSIONS: These results suggest that reduced fat mass is common in patients with classical homocystinuria, and that alterations in homocysteine and choline pathways affect body mass and lipid metabolism.