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.


METHODS
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.
Scaglia
Fernando
F
Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA. fscaglia@bcm.tmc.edu
Scheuerle
Angela E
AE
Towbin
Jeffrey A
JA
Armstrong
Dawna L
DL
Sweetman
Lawrence
L
Wong
Lee-Jun C
LJ
D015415:Biomarkers / Q000652:urine; D002331:Carnitine / Q000031:analogs & derivatives* / Q000032:analysis; D004272:DNA, Mitochondrial / Q000235:genetics; D005260:Female; D005977:Glutarates / Q000652:urine; D006801:Humans; D007231:Infant, Newborn; D017240:Mitochondrial Myopathies / Q000150:complications* / Q000175:diagnosis / Q000378:metabolism*; D009154:Mutation; D009963:Orotic Acid / Q000652:urine; D012202:Reye Syndrome / Q000150:complications* / Q000175:diagnosis / Q000378:metabolism*; D017180:Tachycardia, Ventricular / Q000150:complications* / Q000378:metabolism*
D015415:Biomarkers; D004272:DNA, Mitochondrial; D005977:Glutarates; C116917:acylcarnitine; C022034:3-methylglutaconic acid; D009963:Orotic Acid; D002331:Carnitine