CPS1 deficiency caused by CPS1 gene mutation usually leads to accumulation of ammonia in the blood and thereby presents severe hyperammonemia, which is neurotoxic resulting in neonatal death or severe and irreversible brain damage in the developing and mature brain (Funghini et al., 2012; Choi et al., 2017; Rokicki et al., 2017; Yang et al., 2017). This evidence concerns the gene CPS1 and Hyperammonemia.