Interestingly, some epileptic encephalopathy and ASD genes are separately implicated in psychiatric presentations: variants in KCNQ2 [44, 45] and KCNQ3 [46] may influence susceptibility to bipolar disorder (BPD), while alterations affecting ERBB4 [47], GRIN2A [48], GRIN2B [49], NRXN1 [49–54], PCDH19 [55], SCN2A [56], SLC12A5 [57], and TCF4 [58, 59] may mediate risk for schizophrenia (SCZ). This evidence concerns the gene PCDH19 and Epileptic encephalopathy.