Tandem mass spectrometry and genetic variant analysis of four neonates with very long chain acyl-coenzyme A dehydrogenase deficiency / 中华医学遗传学杂志

OBJECTIVE@#To analyze the clinical features and genetic variants in four neonates with very long chain acyl-coenzyme A dehydrogenase (VLCAD) deficiency.@*METHODS@#Neonates with a tetradecenoylcarnitine (C14:1) concentration at above 0.4 μmol/L in newborn screening were recalled for re-testing. Four neonates were diagnosed with VLCAD deficiency by MS-MS and genetic testing, and their clinical features and genotypes were analyzed.@*RESULTS@#All cases had elevated blood C14:1, and the values of first recalls were all lower than the initial test. In 2 cases, the C14:1 had dropped to the normal range. 1 case has remained at above 1 μmol/L after the reduction, and the remainder one case was slightly decreased. In total eight variants of the ADACVL genes were detected among the four neonates, which included 5 missense variants and 3 novel variants (p.Met344Val, p.Ala416Val, c.1077+6T>A). No neonate showed salient clinical manifestations.@*CONCLUSION@#Above findings have enriched the spectrum of ADACVL gene mutations and provided a valuable reference for the screening and diagnosis of VLCAD deficiency.

Analysis of ACADVL gene variations among nine neonates with very long chain acyl-coA dehydrogenase deficiency / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical features and variations of ACADVL gene in 9 neonates with very long chain acyl-coenzyme A dehydrogenase deficiency (VLCADD).@*METHODS@#VLCADD was suspected based on the results of neonatal screening by tandem mass spectrometry (MS-MS), with tetradecenoylcarnitine ± tetradecenoylcarnitine/octanoylcarnitine (C14: 1 ± C14: 1/C8) as the mark indexes. Infants with positive outcome were confirmed by sequencing of the ACADVL gene.@*RESULTS@#Among 9 VLCADD cases, one case lost during follow-up, the observed phenotypes comprised 2 with severe early-onset form, 1 with hepatic form and 5 with late-onset form. Optimal outcome was acquired for all patients except the 2 early-onset cases. In total 16 ACADVL variations were detected among the 9 infants, which included 8 novel variations (c.96-105del GCCCGGCCCT, c.541C>T, c.863T>G, c.878+1G>C, c.895A>G, c.1238T>C, c.1276G>A, and c.1505T>A) and 11 missense variations. There were 9 genotypic combinations, including 1 homozygote and 8 compound heterozygotes. Except for two patients carrying null variations, all had a good outcome.@*CONCLUSION@#VLCADD is relatively rare in southern China, for which late-onset form is common. Carriers of null variations of the ACADVL gene may have relatively poorer clinical outcome. Above results will provide valuable information for the diagnosis and management of VLCADD.

Clinical features and ACADVL gene mutation spectrum analysis of 11 Chinese patients with very long chain acyl-CoA dehydrogenase deficiency / 中华儿科杂志

<p><b>OBJECTIVE</b>To investigate the clinical and laboratory features of very long chain acyl-CoA dehydrogenase deficiency ( VLCADD ) and the correlations between its genotype and phenotype.</p><p><b>METHOD</b>Eleven patients diagnosed as VLCADD of Shanghai Jiaotong University School of Medicine seen from September 2006 to May 2014 were included. There were 9 boys and 2 girls, whose age was 2 d-17 years. Analysis was performed on clinical features, routine laboratory examination, and tandem mass spectrometry (MS-MS) , gas chromatography mass spectrometry (GC-MS) and genetic analysis were conducted.</p><p><b>RESULT</b>All cases had elevated levels of blood tetradecanoylcarnitine (C14:1) recognized as the characteristic biomarker for VLCADD. The eleven patients were classified into three groups: six cases in neonatal onset group, three in infancy onset group form patients and two in late onset group. Neonatal onset patients were characterized by hypoactivity, hypoglycemia shortly after birth. Infancy onset patients presented hepatomegaly and hypoglycemia in infancy. The two adolescent patients showed initial manifestations of exercise intolerance or rhabdomyolysis. Six of the eleven patients died at the age of 2-8 months, including four neonatal onset and two infant onset patients, with one or two null mutations. The other two neonatal onset patients were diagnosed since early birth through neonatal screening and their clinical manifestation are almost normal after treatments. Among 11 patients, seventeen different mutations in the ACADVL gene were identified, with a total mutation detection rate of 95.45% (21/22 alleles), including eleven reported mutations ( p. S22X, p. G43D, p. R511Q, p. W427X, p. A213T, p. C215R, p. G222R, p. R450H, p. R456H, c. 296-297delCA, c. 1605 + 1G > T) and six novel mutations (p. S72F, p. Q100X, p. M437T, p. D466Y, c. 1315delG insAC, IVS7 + 4 A > G). The p. R450H was the most frequent mutation identified in three alleles (13.63%, 3/22 alleles), followed by p. S22X and p. D466Y mutations which were detected in two alleles (9.09%, 2/22 alleles).</p><p><b>CONCLUSION</b>The ACADVL gene mutations were heterozygous in our patients. The mortality of neonatal onset form and infant onset form is much higher than the late onset form patients, suggesting a certain correlation between the genotype and phenotype was found. The earlier diagnosis and treatment of VLCADD are of vital importance for the improvement of the prognosis of the patients.</p>

Estudio de la deficiencia de acil-CoA deshidrogenasa de cadena muy larga con cardiomiopatía mediante el uso de un sustrato deuterado / Study of very long chain acyl-CoA dehydrogenase (VLCAD) deficiency with cardiomyopathy using a deuterated substrate / Estudo da deficiência de acil-CoA desidrogenase de corrente muito longa com cardiomiopatia mediante o uso de um substrato deuterado Estudo da deficiência de acil-CoA desidrogenase de corrente muito longa com cardiomiopatia mediante o uso de um substrato deuterado

Introducción: la deficiencia de acil-CoA deshidrogenasa de cadena muy larga (VLCAD) se manifiesta en los primeros meses de vida con cardiomiopatía hipertrófica o dilatada y arritmias, que pueden llegar a ser letales. Objetivo: analizar la producción de metabolitos en fibroblastos de pacientes con deficiencia de VLCAD y cardiomiopatía, incubados con ácido oleico deuterado. Materiales y métodos: se incubaron fibroblastos de cuatro pacientes con deficiencia de VLCAD y cardiomiopatía y 10 de controles en presencia de ácido oleico deuterado. Resultados y conclusión: en pacientes con esta deficiencia se encontró un perfil característico luego de la incubación de los fibroblastos. Esta prueba se podría usar para confirmar in vitro la deficiencia de VLCAD con cardiomiopatía.

Introduction: Deficiency of VLCAD is present in the early months of life, with hypertrophic or dilated cardiomyopathy and arrhythmias which may be lethal. Objective: To analize the production of metabolites in fibroblasts from patientes with VLCAD deficiency and cardiomyopathy incubated with deuterated oleic acid. Materials and methods: Fibroblasts from four patients with VLCAD deficiency and cardiomyopathy and from ten controls were incubated in the presence of deuterated oleic acid. Results and conclusison: A characteristic profile was found in the fibroblastos of patients with VLCAD after the described incubation. This test could be used to confirm VLCAD deficiency with cardiomyopathy.

Introdução: a deficiência de acil-CoA desidrogenase de corrente muito longa (VLCAD) manifesta-se nos primeiros meses de vida com cardiomiopatia hipertrófica ou dilatada e arritmias, que podem chegar a ser letais. Objetivo: analisar a produção de metabólitos em fibroblastos de pacientes com deficiência de VLCAD e cardiomiopatia, incubados com ácido oleico deuterado. Materiais e métodos: incubaram-se fibroblastos de quatro pacientes com deficiência de VLCAD e cardiomiopatia e 10 de controles em presença de acido oleico deuterado. Resultados e conclusão: em pacientes com esta deficiência se encontrou um perfil característico depois da encubação dos fibroblastos. Esta prova se poderia usar para confirmar in vitro a deficiência de VLCAD com cardiomiopatia.

Geração de espécies reativas de oxigênio (ERO) mitocondriais: papel das Acil-CoA desidrogenases de cadeia muito longa / Generation of mitochondrial reactive oxygen species (ROS): role of very long chain acyl-coA dehydrogenases

Dietas hiperlipídicas e a esteatose hepática são condições extremamente prevalentes. Trabalhos anteriores mostraram que a esteatose está associada a um aumento na geração de espécies reativas de oxigênio (ERO), e que isso pode mediar danos no fígado. Neste trabalho nós investigamos os possíveis mecanismos que desencadeiam os aumentos nas taxas de geração de ERO por meio da administração de dietas hiperlipídicas. Nós descobrimos que mitocôndrias de animais sujeitos a dietas hiperlipídicas não apresentaram diferenças significativas quanto a capacidade respiratória máxima e acoplamento, mas eram capazes de gerar mais ERO especificamente quando usados substratos do metabolismo de ácidos graxos. Além disso, foi observado que muitas isoformas de acil-CoA desidrogenases estavam mais expressas nos fígados de animais alimentados pela dieta hiperlipídica. No entanto, quando realizados ensaios de atividade enzimática apenas a acil CoA desidrogenase de cadeia longa (VLCAD) foi mais ativa. Estudos conduzidos com mitocôndrias permeabilizadas e expostas a grupos acil-CoA de diferentes tamanhos sugerem que a VLCAD pode ser uma fonte da produção aumentada de ERO em animais submetidos a dietas hiperlipídicas. Esta produção foi estimulada pela ausência de NAD+. Concluindo, nossos estudos descobriram uma nova fonte importante na geração de ERO estimulada por dietas hiperlipídicas, a VLCAD

High fat diets and accompanying hepatic steatosis are highly prevalent conditions. Previous work has shown that steatosis occurs concomitantly with enhanced reactive oxygen species (ROS) generation, which may mediate further liver damage. Here we investigated mechanisms leading to enhanced ROS generation following high fat diets (HFD). We found that mitochondria from HFD livers present no differences in maximal respiratory rates and coupling, but generate more ROS specifically when fatty acids are used as substrates. Indeed, many acyl-CoA dehydrogenase isoforms were found to be more highly expressed in HFD livers, although only the very long chain acyl-CoA dehydrogenase (VLCAD) was more functionally active. Studies conducted with permeabilized mitochondria and different chain length acyl-CoA derivatives suggest that VLCAD is a source of enhanced ROS production in mitochondria from HFD animals. This production is stimulated by the lack of NAD+. Overall, our studies uncover VLCAD as a novel, diet-sensitive, source of mitochondrial ROS

Critical illness in energy metabolism genetic disorder: rhabdomyolysis, acute kidney injury, respiratory arrest / Enfermedad crítica por trastorno genético en el metabolismo de la energía: rabdomiolisis, lesión renal aguda, paro respiratorio

In very long-chain acylCoA dehydrogenase deficiency (VLCAD), the activity of this enzyme is either reduced or absent with the inability to use long-chain fatty acids as energy substrates. A 25-year old male with VLCAD was admitted to the Emergency Department of Policlinico Teaching Hospital (Modena, Italy) for generalized weakness and oliguria, after a period of physical and mental stress and inadequate compliance to a long-chain fatty acid free diet. Laboratory tests were compatible with acute kidney injury. Seventy-two hours after admission, the subject had an episode of chest pain with elevated markers of myocardial necrosis. The rapid deterioration of muscular strength and the subsequent worsening respiratory failure necessitated ventilator support within the local Medical Intensive Care Unit. There, the patient showed a prompt normalization of respiratory parameters and a steady improvement of renal function. An inadequate compliance to lifestyle and dietary restriction in VLCAD may trigger severe and potentially lethal crisis. The in-hospital management of these patients calls for early intensive care admission as their conditions may deteriorate without warning.

En el caso de deficiencia de acylCoA deshidrogenasa de cadena muy larga (VLCAD), o bien se reduce la actividad de esta enzima, o la misma se halla ausente con la consiguiente incapacidad para utilizar los ácidos grasos de cadena larga como sustratos de energía. Un hombre de 25 años fue ingresado con VLCAD fue admitido en el Departamento de emergencia del Hospital Policlínico Docente Hospital de Modena, en Italia, a causa de presentar debilidad generalizada y oliguria, después de un período de estrés físico y mental, y por no cumplir adecuadamente con una dieta libre de ácidos grasos de cadena larga. Las pruebas de laboratorio eran compatibles con una lesión renal aguda. Setenta y dos horas después de su ingreso, el sujeto tuvo un episodio de dolor en el pecho con marcadores elevados de necrosis miocárdica. El rápido deterioro de la fuerza muscular, y el posterior empeoramiento de la insuficiencia respiratoria requirieron el apoyo de un ventilador en la Unidad de Cuidados Médicos Intensivos. Una vez allí, el paciente mostró una pronta normalización de los parámetros respiratorios, y una constante mejoría de la función renal. Un inadecuado cumplimiento con las restricciones dietéticas y el estilo de vida en los casos de VLCAD, pueden desatar una crisis grave y potencialmente fatal. El tratamiento intrahospitalario de estos pacientes requiere un ingreso temprano en cuidados intensivos, ya que sus condiciones pueden deteriorarse sin previo aviso.

Implementación diagnóstica de la deficiencia de acil-CoA deshidrogenasa de cadena muy larga / Diagnostic implementation of very long chain acyl-CoA dehydrogenase deficiency / Implementação diagnóstica da deficiência de acil-CoA desidrogenase de cadeia muito longa

La enzima acil-CoA deshidrogenasa de cadena muy larga (VLCAD) es un homodímero que cataliza la reacción inicial de la ß-oxidación mitocondrial de los ácidos grasos. El presente estudio tuvo como objetivo el análisis de los metabolitos producidos por fibroblastos incubados en presencia de sustratos tritiados vs. deuterados, como herramienta diagnóstica de la deficiencia de VLCAD. Fue encontrada severamente deprimida la oxidación de los sustratos tritiados en los fibroblastos de pacientes con esta enfermedad, asimismo la incubación con sustratos deuterados aportó un perfil característico en esta deficiencia. El método de valoración de agua tritiada, aunque inespecífico, debido a que la oxidación de sustratos tritiados también puede estar deprimida en otras deficiencias, es un buen método para sugerir una deficiencia de acil- CoA deshidrogenasa de cadena muy larga, si el análisis se compara con otros hallazgos propios de la deficiencia enzimática. Sin embargo, la determinación de los metabolitos deuterados es más específica, por encontrarse un perfil característico que muestra niveles elevados de los ácidos grasos octanoico, decanoico, dodecenoico, dodecanoico, tetradecenoico, tetradecanoico y hexadecenoico, lo que la hace diferente de otras deficiencias enzimáticas.

Very long-chain acyl-CoA dehydrogenase (VLCAD) is a homodimer that catalyzes the initial reaction of fatty acid ß-oxidation. The objective of the present study was to analyse the metabolites produced by fibroblasts incubated with tritiated vs. deuterated substrates, as a diagnostic tool for the diagnosis of VLCAD deficiency. A severe depression for oxidizing the tritiated substrates was observed for these patients' fibroblasts, and a characteristic profile for this deficiency was found when incubating fibroblasts with deuterated substrates. The method which evaluates the production of tritiated water is nonspecific as the oxidation of tritiated substrates can be found depressed in other fatty acid ß-oxidation disorders; however this method can suggest VLCAD deficiency if the tritiated water measurement is compared with others findings related to this deficiency. On the other hand the measurement of deuterated metabolites is more specific as a characteristic profile was found for this deficiency showing increased levels of the following organic acids: octanoic, decanoic, dodecenoic, dodecanoic, tetradecenoic, tetradecanoic and hexadecanoic, which is different from other fatty acid ß-oxidation disorders.

A enzima acil-CoA desidrogenase de cadeia muito longa (VLCAD) é um homodímero que catalisa a reação inicial da ß-oxidação mitocondrial dos ácidos graxos. O presente estudo teve como objetivo a análise dos metabólitos produzidos por Ibroblastos incubados em presença de substratos tritiados vs. deuterados, como ferramenta de diagnóstico da deIciência de VLCAD. Foi encontrada severamente deprimida a oxidação dos substratos tritiados nos Ibroblastos de pacientes com esta doença, do mesmo modo a incubação com substratos deuterados deu um perIl característico nesta deIciência. O método de avaliação de água tritiada, embora não especíIco, devido a que a oxidação de substratos tritiados também pode estar deprimida em outras deIciências, é um bom método para sugerir uma deIciência de acil-CoA desidrogenase de cadeia muito longa, se a análise é comparada com outros achados próprios da deIciência enzimática. Entretanto, a determinação dos metabólitos deuterados é mais especiIca, devido a que se encontra um perIl característico que mostra níveis elevados dos ácidos graxos octanoico, decanoico, dodecenoico, dodecanoico, tetradecenoico, tetradecanoico e hexadecenoico, o que a torna diferente de outras deIciências enzimáticas.

MCT oil-based diet reverses hypertrophic cardiomyopathy in a patient with very long chain acyl-coA dehydrogenase deficiency.

Very long chain acyl-CoA dehydrogenase (VLCAD) deficiency is one of the genetic defects of mitochondrial fatty acid beta-oxidation presenting in early infancy or childhood. If undiagnosed and untreated, VLCAD deficiency may be fatal, secondary to cardiac involvement. We assessed the effect of replacing part of the fat in the diet of a 2 ½-month-old male infant, who was diagnosed with VLCAD deficiency,with medium-chain triglyceride (MCT) oil and essential fats. The patient presented with vomiting, dehydration, and was found to have persistent elevation of liver function tests, hepatomegaly, pericardial and pleural effusion, right bundle branch block, and biventricular hypertrophy. Because of the cardiomyopathy, hepatomegaly, and an abnormal acylcarnitine profile and urine organic acids, he was suspected of having VLCAD deficiency. This was confirmed on acyl-coA dehydrogenase, very long chain (ACADVL) gene analysis. He was begun on an MCT oil-based formula with added essential fatty acids, uncooked cornstarch (around 1 year of age), and frequent feeds. By 7 months of age, cardiomyopathy had reversed and by 18 months of age, all cardiac medications were discontinued and hypotonia had improved such that physical therapy was no longer required. At 5 years of age, he is at the 50th percentile for height and weight along with normal development. Pediatricians need to be aware about the basic pathophysiology of the disease and the rationale behind its treatment as more patients are being diagnosed because of expansion of newborn screen. The use of MCT oil as a medical intervention for treatment of VLCAD deficiency remains controversial mostly because of lack of clear phenotype-genotype correlations, secondary to the genetic heterogeneity of the mutations. Our case demonstrated the medical necessity of MCT oil-based nutritional intervention and the need for the further research for the development of specific guidelines to improve the care of these patients.