Clinical and biochemical studies on periodic hyperammonemia with hyperlysinemia and homocitrullinuria.

An 18-year-old mentally and physically retarded boy, suffering from episodes of anorexia, vomiting, coma and convulsion which have been severer with advance in age, had periodic hyperammonemia, hyperlysinemia and homocitrullinuria. Blood cell arginase activity of the patient on normal diet was markedly reduced after an oral load of L-lysine. The oral loading tests of L-lysine revealed hyperammonemia, hyperlysinemia, hyperargininemia, hypercitrullinemia and homocitrullinuria. Etiology of metabolic error of our patient was discussed in reference to lysine-urea cycle.