RESUMO Paciente portadora de deficiência de acil-CoA desidrogenase de cadeia média (MCADD), com episódios clínicos recorrentes de hipoglicemia e alteração de consciência, apresentou alterações no perfil de acilcarnitinas em sangue por espectrometria de massas em tandem e na análise de ácidos orgânicos urinários por cromatografia gasosa acoplada à espectrometria de massa. Este caso demonstra a importância da coleta de amostra biológica em jejum (se possível) quando há suspeita de MCADD e ressalta que o tempo/momento de coleta da amostra biológica é importante para o diagnóstico, considerando a possibilidade de a MCADD ser subdiagnosticada no Brasil.

ABSTRACT Female patient carrier of medium-chain acyl-CoA dehydrogenase deficiency (MCADD) with recurrent clinical episodes of hypoglycemia and altered level of consciousness, presented changes in blood acylcarnitine profile by tandem mass spectrometry and in the urinary organic acid analysis by gas chromatography/mass spectrometry (GC/MS). This case demonstrates the importance of fasting prior biological sample collection (when possible) when MCADD is suspected, and emphasizes that the time/momentum of biological sample collection is crucial to diagnosis, considering the possibility that MCADD is underdiagnosed in Brazil.

RESUMEN Paciente portadora de deficiencia de acil-CoA deshidrogenasa de cadena media (MCADD) con episodios clínicos recurrentes de hipoglucemia y alteración de consciencia presentó mudanzas en el perfil de acilcarnitinas en la sangre con técnicas de espectrometría de masas en tándem y en el análisis de ácidos orgánicos urinarios mediante cromatografía de gases acoplada a espectrometría de masas. Este caso demuestra la importancia de la toma de muestras biológicas en ayunas (se posible) cuando se sospecha de MCADD y destaca que el tiempo/momento de extracción de la muestra biológica es valioso para el diagnóstico, considerando la posibilidad de que la MCADD es subdiagnosticada en Brasil.

Abstract Citrullinemia type 1 (CTLNI), long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHADD), and mut0 methylmalonic acidemia (mut0 MMA) are inborn errors of metabolism (IEMs) associated with sudden unexpected death in infancy (SUDI). Its most common pathogenic variants are: c.1168G>A (CTLNI, ASS1 gene), c.1528G>C (LCHADD, HADHA gene), c.655A>T and c.1106G>A (mut0 MMA, MUT gene). Considering the absence of estimates regarding the incidence of these diseases in Brazil, this study sought to investigate the prevalence of its main pathogenic variants in a healthy population in the southern region of the country. A total of 1,000 healthy subjects from Rio Grande do Sul were included. Genotyping was performed by real-time PCR. Individuals found to be heterozygous for c.1528G>C underwent further acylcarnitine profile analysis by tandem mass spectrophotometry. Allele and genotype frequencies were calculated considering Hardy-Weinberg equilibrium. The c.1528G>C variant was detected in heterozygosity in two subjects (carrier frequency = 1:500; allele frequency = 0.001; minimum prevalence of LCHADD = 1: 1,000,000), whose acylcarnitine profiles were normal. Variants c.1168G>A, c.655A>T, and c.1106G>A were not identified. These results denote the rarity of these IEMs in Southern Brazil, highlighting the need to expand the investigation of IEMs in relation to infant morbidity and mortality within the country.

Abstract: Fabry disease (FD) is an X-linked inherited disease and occurs due to mutations in GLA gene that encodes the α-galactosidase enzyme. Consequently, there is an accumulation of enzyme substrates, namely globotriaosylceramide (GB3). FD is a multisystemic disease, caused by storage of GB3 in vascular endothelia, with significant renal, cardiac and vascular involvement. The aim of this work was to evaluate the in vitro effect of GB3 on electron transport chain complexes (ETC) and redox parameters. Biochemical biomarkers were determined in homogenates of cerebral cortex, kidneys and liver of Wistar rats in the presence or absence of GB3 at concentrations of 3, 6, 9 and 12 mg/L. We found that GB3 caused an increase of ETC complexes II and IV activities, increased production of reactive species and decreased superoxide dismutase enzyme activity in homogenates of cerebral cortex. As well also increased production of reactive species and superoxide dismutase activity in kidney homogenates. The results obtained in our work suggest that GB3 interferes in ETC complexes II and IV activities, however, the magnitude of this increase seems to be too low to present a physiologically importance. However, the imbalance in cellular redox state indicating that these alterations may be involved in the pathophysiology of FD, mainly in renal and cerebral manifestations.

Abstract Organic acidurias and aminoacidopathies are groups of frequent inborn errors of metabolism (IEMs), which are caused by mutations in specific genes that lead to loss of protein/enzyme or transport function with important deleterious effects to cell metabolism. Since a considerable number of such disorders are potentially treatable when diagnosed at an early stage of life, diagnosis is crucial for the patients. In the present report, we describe symptomatic individuals referred to our service that were diagnosed with these disorders from 2006 to 2016. We used blood and urine samples from 21,800 patients suspected of aminoacidopathies or organic acidemias that were processed by the analytical techniques reverse phase high-performance liquid chromatography for amino acid quantification and gas chromatography coupled to mass spectrometry for organic acid detection. Analysis of dried blood spots by liquid chromatography-tandem mass spectrometry was used in some cases. We detected 258 cases of organic acidurias, and 117 patients with aminoacidopathies were diagnosed. Once diagnosis was performed, patients were promptly submitted to the available treatments with clear reduction of mortality and morbidity. The obtained data may help pediatricians and metabolic geneticists to become aware of these diseases and possibly expand newborn screening programs in the future.

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

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

OBJETIVO: o objetivo deste trabalho foi o de verificar a prevalência das acidúrias orgânicas em pacientes brasileiros de alto risco. MÉTODOS: técnicas laboratoriais para a detecção e quantificação de ácidos orgânicos por cromatografia gasosa acoplada à espectrometria de massa foram implantadas em Porto Alegre, Brasil. Foram analisados 1.480 pacientes suspeitos, investigados entre janeiro de 1994 e junho de 2000. RESULTADOS: foram diagnosticados 73 (4,9%) casos de acidemias (acidúrias) orgânicas entre os indivíduos testados. Na maioria desses pacientes a terapia resultou em rápida melhora na sua sintomatologia, distintamente de nossos casos previamente diagnosticados em outros laboratórios na Europa e nos Estados Unidos, quando muitos pacientes faleciam antes que quaisquer medidas pudessem ser tomadas. CONCLUSÕES: estes resultados mostram a importância de diagnosticar as acidúrias orgânicas in loco mesmo em países em desenvolvimento, apesar dos custos extras envolvidos.

OBJECTIVE: to determine the prevalence of organic acidurias in high-risk Brazilian patients. METHODS: laboratory techniques for the detection and quantification of organic acids by gas chromatography/mass spectrometry were implemented in Porto Alegre, Brazil. We investigated 1,480 patients suspected of organic aciduria between January 1994 and June 2000. RESULTS: seventy three (4.9%) cases of organic acidemias (acidurias) were diagnosed among the tested individuals. In most of these patients, prompt therapy resulted in rapid symptom improvement; these results are completely different from our previous cases diagnosed in other laboratories in Europe and the United States, where several patients died before any measures could be taken. CONCLUSIONS: these results demonstrate the importance of diagnosing organic acidurias in loco even in developing countries, in spite of the extra costs involved.

A adrenoleucodistrofia ligada ao X (X-ALD) é uma desordem hereditária do metabolismo peroxissomal, bioquimicamente caracterizada pelo acúmulo de ácidos graxos de cadeia muito longa (`very long chain fatty acids"- VLCFA) em diferentes tecidos e em fluidos biológicos, sendo os principais ácidos acumulados o hexacosanóico (C26:0) e o tetracosanóico (C24:0). O acúmulo destes ácidos graxos está associado com desmielinização cerebral e insuficiência adrenal. A incidência desta condição é estimada em 1 para 25.000 em homens. Pelo menos seis fenótipos podem ser distinguidos, sendo a adrenoleucodistrofia (ALD) cerebral infantil e a adrenomieloneuropatia (AMN) os mais comuns. O tratamento preconizado consiste na utilização da mistura gliceroltrioleato/gliceroltrierucato (GTO/GTE), conhecida como Óleo de Lorenzo, combinada com dieta pobre em VLCFA. Existem ainda, terapias alternativas como transplante de medula óssea e imunossupressão, além da utilização de lovastatina e fenilacetato de sódio. Neste trabalho fez-se uma avaliação do tratamento com Óleo de Lorenzo associado à dieta restrita em VLCFA de 7 pacientes homens com X-ALD analisando a evolução clínica e bioquímica. Os pacientes apresentaram uma redução média de 50% nos valores de C26:0 e de 42,8% na razão C26:0/C22:0 após o início do tratamento. A maioria dos pacientes permaneceu clinicamente bem e aproximadamente 30% dos pacientes apresentaram uma progressão rápida no curso clínico da doença. Parece não haver uma clara correlação bioquímico-clínica do tratamento. Os resultados nos mostram que novas terapias mais eficazes para X-ALD são necessárias para que se possa obter um melhor prognóstico da doença com progressão mais lenta dos sintomas apresentados ou mesmo reversão dos sintomas já presentes nos pacientes.

X-Linked adrenoleukodystrophy (X-ALD) is a hereditary disorder of the peroxisomal metabolism biochemically characterized by the accumulation of very long chain fatty acids (VLCFA) in tissues and biological fluids. The major accumulated acids are hexacosanoic acid (C26:0) and tetracosanoic acid (C24:0). The disorder is characterized clinically by central and peripheral demyelination and adrenal insufficiency closely related to the accumulation of fatty acids. The incidence of X-ALD is estimated to be 1:25,000 males. At least six phenotypes can be distinguished. The most common phenotypes are childhood cerebral ALD and adrenomyeloneuropathy (AMN). The recommended therapy consists of the use of the glyceroltrioleate/glyceroltrierucate (GTO/GTE) mixture, known as Lorenzo's Oil, combined with a VLCFA-poor diet. There are alternative treatments such as bone marrow transplantation and immunosuppression, as well as the use of lovastatin and sodium phenylacetate. In the present study we report the clinical and biochemical course of 7 male patients with X-ALD treated with Lorenzo's Oil and a VLCFA-restricted diet. Treatment produced 50% reduction in C26:0 and 42.8% reduction in the C26:0/C22:0 ratio. Most patients remained clinically well, although approximately 30% of them presented a rapid clinical deterioration. The results showed a poor biochemical-clinical correlation for treatment, indicating that new therapies for X-ALD are needed in order to obtain a better prognosis for patients.

Adrenoleucodistrofia (X-ALD) é uma desordem peroxissomal com padrão de herança ligada ao X, fenotipicamente heterogênea, caracterizada por uma progressiva desmielinização da substância branca do sistema nervoso central e por insuficiência adrenal. Foram investigados por nós 15 pacientes do sexo masculino com sinais clínicos sugestivos de X-ALD, com idade entre 7 e 39 anos, diagnosticados entre 108 pacientes encaminhados para investigação por suspeita clínica. Os níveis plasmáticos dos ácidos graxos de cadeia muito longa (VLCFA) foram dosados em nosso laboratório através de cromatografia gasosa (GC). Onze (73%) casos da forma infantil de X-ALD (ALD) e 4 (27%) casos de adrenomieloneuropatia (AMN) foram diagnosticados. Insuficiência leucodistrofia adrenal e fraqueza muscular foram os sinais mais freqüentes, aparecendo em 80, 53 e 40% dos casos, respectivamente. O conhecimento dos médicos sobre a possibilidade da X-ALD parece ser pequeno, o que pode ser concluído a partir da elevada idade no diagnóstico e do grande intervalo entre o início dos sintomas e o diagnóstico. Neste trabalho, que relata a primeira série brasileira de pacientes com X-ALD, procuramos enfatizar os sinais e sintomas que são relevantes para a suspeita diagnóstica, uma vez que a identificação precoce dos casos parece ser importante para o sucesso do tratamento. Além disso, o diagnóstico permite a identificação de portadores, os quais podem se beneficiar do aconselhamento genético e do diagnóstico pré-natal.

Adrenoleukodystrophy (X-ALD) is an X-linked recessively inherited peroxisomal disorder, phenotypically heterogeneous, characterized by progressive white-matter demyelination of the central nervous system and adrenocortical insufficiency. We investigated 15 male X-ALD patients varying in age from 7 to 39, diagnosed among 108 suspected patients referred for investigation. Plasma levels of very long chain fatty acids (VLCFA) were measured at our laboratory using gas chromatography (GC). Eleven cases of childhood X-ALD and four cases of adrenomyeloneuropathy (AMN) were diagnosed. Adrenal leukodystrophy insufficiency and limb weakness were the most frequent symptoms, appearing in 12, 8 and 6 of the patients, respectively. Physician awareness of X-ALD seems inadequate to judge by age at diagnosis and lengthy interval between the start of symptoms and diagnosis. This is the first published series of Brazilian patients with X-ALD. We determined signs and symptoms relevant for diagnosis, as early identification seems important for treatment outcome. In addition, diagnosis identifies carriers, who could benefit from genetic counselling and prenatal diagnosis.