DDAH1 and neurodevelopmental disorder: In addition, genes involved in neural development (REST [26], ZNRF1 [27], RabGEF1 [28], and CUX1 [29]), neurotransmission (SYN2 [30] and DDAH1 [31]; Fig. 1e (left)), noradrenergic neurotransmitter system (PHOX2A), voltage channels (KCNJ8 and CACNG8 [32]), and peroximal lipid metabolism (PHYH; Fig. 1e (right)) clustered among the top ranked genes, all of which have been implicated in neurodevelopmental disorders.