Hyperammonemic crisis in a child with ATP synthase deficiency caused by mtDNA mutation m.8851T>C

Abstract

Life-threatening hyperammonemia is uncommon in patients with mitochondrial disorders (MDs).When present, it is usualy due to TMEM70 deficiency and only rarely is it noted in other MDs. Hyperammonemia was documented in patients with Barth syndrome, maternally inherited Leigh syndrome (MILS), pyruvate dehydrogenase deficiency, pyruvate carboxylase deficiency, complex III deficiency caused by UQCRC2 deficiency, and patients with CoQ deficiency.

Here we present a fatal outcome due to newly documented hyperammonemia in a previously reported girl with ATP synthase deficiency caused by mutation m.8851T>C in mitochondrial MTATP6.