CPS1 and hyperinsulinemic hypoglycemia, familial, 4: Until recently, next-generation sequencing (NGS), a powerful DNA sequencing technology, has revolutionized genomic research with great utility in the molecular diagnosis of genetic disorders (Choi et al., 2017; Jia et al., 2017; Rokicki et al., 2017; Li et al., 2018; Zhang et al., 2018), and has been proven reliable and important to detect CPS1 mutation for early diagnosis of CPS1D, as the severity of clinical manifestations in CPS1D patients is determined by the extent of CPS1 deficiency (Choi et al., 2017; Chen et al., 2018; Zhang et al., 2018).