Mitochondrial abnormalities of liver in primary ornithine transcarbamylase deficiency

Deficiency of hepatic ornithine transcarbamylase (EC 2.1.3.3) activity in a 17-month-old female patient is described. Enzyme activity was 11% of the mean control value. Electron microscopic examination of the liver specimen, taken by percutaneous needle biopsy, revealed striking abnormalities of the mitochondria: bud-like projections, sausage-link appearance, elongation with short cristae, or the presence of parallel arrays of tubules. The abnormalities do not resemble those seen in Reye's syndrome.