GPT and Hyperammonemia: However, laboratory tests revealed elevated liver enzymes [Alanine aminotransferase: ALT, 73 U/L [normal: 9–50 U/L]; Aspartate aminotransferases: 113 U/L [normal: 15–40 U/L]) and persistent hyperammonemia (82 μmol/L, normal:9–47μmol/L).