RESUMO
INTRODUCTION: Massive neonatal screening for phenylketonuria (PKU) began in developed countries in 1963, and eventually disappeared as a cause of mental retardation. Yet, this is not the case in most developing countries. AIM: To describe the phenotype and the genotype of PKU patients with a delayed diagnosis in order to draw attention to the importance of neonatal studies and molecular diagnosis. PATIENTS AND METHODS: Clinical data were collected from five unrelated patients by means of a medical assessment. The molecular study was conducted using the DGGE, sequencing and/or restriction analysis techniques to search for mutations in the PAH gene. RESULTS. Owing to the delayed diagnosis all the patients presented severe clinical manifestations, such as psychomotor retardation, atypical behaviours and language disorders. Four of them presented epilepsy and there were two cases of microcephaly. The phenotype was as expected, given the genotype. Seven different mutations were detected in the 10 alleles that were studied. The IVS10nt +5 g>t mutation was the most frequent, followed by the Venezuelan mutation S349L. Furthermore, two patients presented mutated proteins with residual activity, and good results were obtained using BH4 therapy. CONCLUSIONS: In our country, as in most developing countries, PKU neonatal studies are performed but the programme does not cover the whole neonatal population. In this work, we want to stress the importance of neonatal studies in the welfare of children, as well as the use of molecular diagnosis to improve the therapeutic orientation and genetic counselling of the families involved.
Assuntos
Mutação , Fenilcetonúrias/diagnóstico , Fenilcetonúrias/genética , Pré-Escolar , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Fatores de Tempo , VenezuelaRESUMO
L-2-hydroxyglutaric aciduria (L-2-HGA) is a metabolic disease with an autosomal recessive mode of inheritance. It was first reported in 1980. Patients with this disease have mutations in both alleles of the L2HDGH gene. The clinical presentation of individuals with L-2-HGA is somewhat variable, but affected individuals typically suffer from progressive neurodegeneration. Analysis of urinary organic acids reveals an increased signal of 2-hydroxyglutaric acid, mainly as the L-enantiomer. L-2-HGA is known to occur in individuals of various ethnic backgrounds, but up to now mutation analysis has been mainly focused on patients of Turkish and Portuguese origin. This led us to confirm the diagnosis on the DNA level and undertake the corresponding mutation analysis in individuals of diverse ethnicity previously diagnosed with L-2-HGA on the basis of urinary metabolites and clinical/neuroimaging data. In 24 individuals from 17 families with diverse ethnic and geographic origins, 13 different mutations were found, 10 of which have not been reported previously. At least eight of the patients were compound heterozygotes. The identification of two mutations (c.751C > T and c.905C > T in exon 7) in patients with different origins supports the view that they occurred independently in different families. In contrast, the mutation c.788C > T was detected in all six Venezuelan patients originating from the same Caribbean island of Margarita, but not in other patients, thus rendering a founder effect likely. None of the mutations was found in the control population, indicating that they are most probably causative. Mutation analysis may improve the quality of diagnosis and prenatal diagnosis of L-2-HGA.
Assuntos
Oxirredutases do Álcool/genética , Encefalopatias Metabólicas Congênitas/enzimologia , Encefalopatias Metabólicas Congênitas/genética , Mutação , Adulto , Biomarcadores/urina , Encefalopatias Metabólicas Congênitas/diagnóstico , Encefalopatias Metabólicas Congênitas/etnologia , Análise Mutacional de DNA , Progressão da Doença , Europa (Continente)/etnologia , Feminino , Predisposição Genética para Doença , Glutaratos/urina , Humanos , Lactente , Masculino , Paquistão/etnologia , Fenótipo , Valor Preditivo dos Testes , Arábia Saudita/etnologia , Índice de Gravidade de Doença , Venezuela/etnologiaRESUMO
INTRODUCTION: Glutaric aciduria type I is an autosomal recessive inborn error of metabolism that is due to a deficiency of the enzyme glutaryl-CoA dehydrogenase, which gives rise to an accumulation of glutaric and 3-hydroxyglutaric acids in biological fluids. Clinical features present as a sudden-onset severe neurological disorder, characterised by extrapyramidal signs (dystonia-dyskinesia), hypotonia, irritability, macrocephaly and degeneration of the basal ganglia; it may also manifest with unspecific symptoms, such as hypotonia and psychomotor retardation. AIMS: To describe the clinical, biochemical, neuroimaging and molecular aspects in six Venezuelan patients and to highlight the importance of an early diagnosis of glutaric aciduria type I so as to be able to establish early treatment and thus prevent the neurological damage produced by this disease. CASE REPORTS: Two patients were referred because of macrocephaly, hypotonia and psychomotor retardation, and four more following an encephalopathic crisis. In all of them, neuroimaging studies showed delays in myelination, bilateral frontotemporal hypoplasia and symmetric widening of the Sylvian fissures with poor opercularisation. Urinary organic acid analyses showed raised levels of glutaric and 3-hydroxyglutaric acids, and a molecular analysis confirmed the diagnosis. CONCLUSIONS: Organic acid analysis should be indicated in all patients who present macrocephaly, hypotonia, psychomotor retardation or an encephalopathic crisis of unknown causation. This study allowed us to determine the behaviour of the disease in Venezuela, since no epidemiological data exist in the country.
Assuntos
Erros Inatos do Metabolismo dos Aminoácidos/fisiopatologia , Glutaratos/urina , Erros Inatos do Metabolismo dos Aminoácidos/genética , Erros Inatos do Metabolismo dos Aminoácidos/patologia , Encéfalo/patologia , Criança , Pré-Escolar , Aberrações Cromossômicas , Feminino , Humanos , Lactente , Imageamento por Ressonância Magnética , Masculino , VenezuelaRESUMO
INTRODUCTION: Macrocephaly is a pivotal clinical sign, associated with multiple neurological diseases, particularly neurometabolical ones, such as the glutaric aciduria type I (GA I). This aciduria resulting from the genetical deficiency of the enzyme glutaryl-CoA dehydrogenase (GCDH). Is a relatively common cause of acute metabolic brain damage in early childhood. We report on one case of GA I, with early manifestations since fetal period and a novel mutation. CASE REPORT: Our patient was referred due macrocephaly in utero and occipitofrontal head circumference above the 98 percentile for chronologic age during first few months of life, hypotonia and development delay. The metabolic investigations of organic acids in urine and acylcarnitine profile in blood, the brain magnetic resonance and the molecular analyses of the glutaryl-CoA deshidrogenase gene, confirm the diagnosis. The molecular analysis allowed to identify one previously described mutation A293T and a novel mutation IVS5-2 A>G. CONCLUSION: It is important the recognition of in utero macrocephaly as a sign to early diagnosis of glutaric aciduria type I to initiate specific therapy to prevent the encephalopathic crises and minimize brain damage in patients who are already neurologically impaired.
Assuntos
Feto/patologia , Glutaratos/metabolismo , Erros Inatos do Metabolismo/complicações , Erros Inatos do Metabolismo/genética , Malformações do Sistema Nervoso/etiologia , Malformações do Sistema Nervoso/genética , Análise Mutacional de DNA , Feto/anatomia & histologia , Feto/fisiologia , Humanos , Lactente , Recém-Nascido , Masculino , Erros Inatos do Metabolismo/diagnóstico , Malformações do Sistema Nervoso/metabolismo , Malformações do Sistema Nervoso/patologiaRESUMO
INTRODUCTION: L-2-hydroxyglutaric aciduria is a rare inborn error of metabolism, autosomal recessive, identified in about 50 patients. The primary defect is still unknown. The clinical phenotype is variable. Affected individuals show slowly progressive neurodegenerative disorder with cerebellar ataxia and mental retardation. Pyramidal, and extrapyramidal signs, seizures and macrocephaly have been reported. All patients previously described show a pattern of subcortical leukoencephalopathy with nearly empty gyral cores and cerebellar atrophy in neuroimaging studies. The diagnosis is established by detection of increased levels of L-2-hydroxyglutaric acid in urine, plasma and cerebrospinal fluid. CASE REPORTS: We here describe two patients 7 and 9 years old, who presented psychomotor retardation, seizures, progressive cognitive deterioration, and pyramidal, extrapyramidal and cerebellar signs. Magnetic resonance scanning of the brain demonstrated a bilateral subcortical leukoencephalopathy pattern and areas of increased T2-weighted signal in the basal ganglia and cerebellar dentate nuclei. The analysis of organic acids in urine by gas chromatography/mass spectrometry showed elevated 2-hydroxyglutaric acid, 100% of it in the form of L enantiomer. CONCLUSION: The diagnostic consideration is based on clinical findings and typical neuroimaging pattern and is established by detection of L-2-hydroxyglutaric acid in body fluids. Subcortical white matter loss is an important clue to diagnosis.