KCNT1 and Angelman syndrome: One infant was diagnosed with OS, and a likely pathogenic variant was found in KCNQ2. Additionally, another one infant was diagnosed with MPEI, and a likely pathogenic variant was found in KCNT1. As shown in Table 3, three pathogenic CNVs del1p36, del15q11–q13, and del17p13.3 corresponded to 1p36 deletion syndrome, Angelman syndrome, and Miller–Dieker syndrome, respectively.