GPT and ornithine translocase deficiency: It is associated with mild and intermittent hypertransaminasemia: Mean values for alanine aminotransferase (ALT) 191 ± 119 U/L (normal values: 5–40 U/L; 4.8 fold increase in HHHS cases with respect to the upper level); mean values for aspartate aminotransferase (AST) 147 ± 97 U/L (normal values: 7–56 U/L; 2.6 fold increase in HHHS cases with respect to the upper level).