Strikingly, for the first time, we identified three novel pathogenic mutations of CPS1. To our knowledge, there have been so far only three reports of using NGS to detect CPS1 mutations for CPS1D diagnosis (Choi et al., 2017; Chen et al., 2018; Zhang et al., 2018). The gene discussed is CPS1; the disease is carbamoyl phosphate synthetase I deficiency disease.