[A case of ornithine transcarbamylase deficiency presenting severe symptoms in adulthood]

An adult female case of ornithine transcarbamylase (OTC) deficiency is presented in the following. The patient had had past episodes of drowsiness with a duration less than a few minutes several times a year during childhood. She suddenly became comatose at 25 years of age, and died after 13 months of persistent vegetative state. Blood chemistry showed hyperammonemia with no liver cirrhosis or portal-systemic shunt. Plasma amino acid analysis indicated elevated glutamate and glycine levels, and plasma levels of citrulline and arginine to be low. The urinary orotic acid level was high. OTC activity of a liver specimen was 65 percent of the normal level. This is a rare case demonstrating hyperglycinemia and an elevated level of serum OTC. The importance of ruling out defective ureagenesis in adults with disturbed consciousness should be emphasized.