Neonatal presentation of ventricular tachycardia and a Reye-like syndrome episode associated with disturbed mitochondrial energy metabolism

BACKGROUND: Hyperammonemia, hypoglycemia, hepatopathy, and ventricular tachycardia are common presenting features of carnitine-acylcarnitine translocase deficiency (Mendelian Inheritance in Man database: *212138), a mitochondrial fatty acid oxidation disorder with a lethal prognosis. These features have not been identified as the presenting features of mitochondrial cytopathy in the neonatal period. CASE PRESENTATION: We describe an atypical presentation of mitochondrial cytopathy in a 2 day-old neonate. She presented with a Reye-like syndrome episode, premature ventricular contractions and ventricular tachycardia. Initial laboratory evaluation exhibited a large amount of 3-methylglutaconic acid on urine organic acid analysis, mild orotic aciduria and a nonspecific abnormal acylcarnitine profile. The evaluation for carnitine-acylcarnitine translocase deficiency and other fatty acid oxidation disorders was negative. The patient later developed a hypertrophic cardiomyopathy and continued to be affected by recurrent Reye-like syndrome episodes triggered by infections. A muscle biopsy exhibited signs of a mitochondrial cytopathy. During the course of her disease, her Reye-like syndrome episodes have subsided; however, cardiomyopathy has persisted along with fatigue and exercise intolerance. CONCLUSIONS: This case illustrates that, in the neonatal period, hyperammonemia and ventricular tachycardia may be the presenting features of a lethal carnitine-acylcarnitine translocase deficiency or of a mitochondrial cytopathy, associated with a milder clinical course. This association broadens the spectrum of presenting phenotypes observed in patients with disturbed mitochondrial energy metabolism. Also, the presence of 3-methylglutaconic aciduria suggests mitochondrial dysfunction and mild orotic aciduria could potentially be used as a marker of mitochondrial disease

The 3-methylglutaconic acidurias: what’s new?

The heterogeneous group of 3-methylglutaconic aciduria (3-MGA-uria) syndromes includes several inborn errors of metabolism biochemically characterized by increased urinary excretion of 3-methylglutaconic acid. Five distinct types have been recognized: 3-methylglutaconic aciduria type I is an inborn error of leucine catabolism; the additional four types all affect mitochondrial function through different pathomechanisms. We provide an overview of the expanding clinical spectrum of the 3-MGA-uria types and provide the newest insights into the underlying pathomechanisms. A diagnostic approach to the patient with 3-MGA-uria is presented, and we search for the connection between urinary 3-MGA excretion and mitochondrial dysfunction

Mutation Spectrum of Fumarylacetoacetase Gene and Clinical Aspects of Tyrosinemia Type I Disease

Tyrosinemia type I (OMIM 276700) is a rare, autosomal recessive disorder caused by a deficiency in the fumarylacetoacetate hydrolase (FAH) enzyme. This study examined the spectrum of FAH gene mutation in 32 patients with tyrosinemia type I. In addition, clinical and biochemical findings were evaluated to establish a genotype phenotype relationship in the patients. Mutation screening was performed using a 50K custom-designed resequencing microarray chip (TR_06_01r520489, Affymetrix) and sequencing analysis. Of the 12 different mutations found, 6 are categorized as novel. Three of the mutations-IVS6-1G>A, D233V, and IVS3-3C>G-are the most common in Turkish patients, comprising 25%, 17.1%, and 12.5% of mutant alleles, respectively. Clinical evaluations suggest that the spectrum of symptoms observed in the patients with very early and early disease were of the more nonspecific form, whereas the patients with late-presenting disease had more of the distinctive form over the course of the disease. This study adds support to the notion that the D233V mutation is specific to the Turkish population.Wo

Cystic renal dysplasia as a leading sign of inherited metabolic disease.

Contains fulltext : 52537.pdf (publisher's version ) (Closed access)Glutaric acidemia type II and carnitine palmitoyltransferase type II deficiency are rare, but potentially treatable, inherited metabolic diseases. Hallmarks of the early onset form of both conditions are renal abnormalities and neonatal metabolic crisis. In this article, we report on two newborns with cystic renal dysplasia as a leading sign of these metabolic diseases. We focus on the clinical presentation and discuss the diagnostic tests and the available therapeutic options. We conclude that prenatal diagnosis of cystic renal dysplasia should alert the physician to the possibility of these metabolic diseases. This knowledge should prompt careful observation and, where necessary, early intervention during the postnatal period of catabolism