Nevertheless, we found 16p11.2 CNVs (one deletion and one duplication) in two independent patients (P32 and P59), which are known to increase risk of NDD41,42 and are rare in the general population (0.03%).2 The finding of two cases with such CNVs is intriguing and raises question of the genetic architecture of PMS, and by extension on the cumulative genetic risk factors in NDD.43 In addition, we observed abnormal gene dosage of risk-genes for epilepsy such as KCNT1, MYT1L, DEAF1 and SLC25A22 in patients whom had lifetime history of seizures. The gene discussed is KCNT1; the disease is Neurodevelopmental delay.