Pediatria pre prax 6/2016

Late onset of inherited urea cycle disorder – ornithine transcarbamoylase deficiency

Ornithine transcarbamylase deficiency (OTCD) is the most frequent inherited urea cycle disorder. This inherited metabolic disorder (IMD) has gonosomal recessive mode of inheritance and results from a deficiency of the mitochondrial enzyme ornithine transcarbamylase, which catalyses the conversion of ornithine and carbamoyl phosphate to citruline. The cumulation of toxic ammonia and other metabolites are the main cause of the earlier or later clinical manifestation of the disease. The authors present a case report of a thirteen-month-old boy who was taken to hospital due to apathy, overall hypotonia and hyperammonemia. Subsequent metabolic investigation showed the ornithine transcarbamylase deficiency that was confirmed at molecular genetic level.

Keywords: inherited metabolic disorder, ornithine transcarbamylase, urea cycle disorder, hyperammonemia, late onset form