Ornithinemia, Hyperammonemia, and Homocitrullinuria

The effects of varying dietary protein intake, and of supplements of ornithine, arginine, lysine, and proline on a patient with hyperornithinemia, hyperammonemia, and homocitrullinuria were investigated in an attempt to understand the condition. The homocitrulline excretion is increased with increased dietary lysine, and also by increased protein intake. Supplementary ornithine or arginine lowers plasma ammonia levels and simultaneously decreases the excretion of homocitrulline. A possible cause of this disease is a defect in the transport of ornithine into the mitochondria. Arginine supplements may be useful in the treatment of the condition.