PCDH19 and epilepsy: The following genes have been identified as epilepsy etiology: ARX, CACNA1B, CASK, CHRNA2, GRIN2D, KCNQ2, KCNT1, MT-CO3, PCDH19, SCN1A (x2), SLC2A1, SLC12A5, and WWOX. In an early study, Jaxybayeva et al. [6] identified a genetic cause in 80% (12/15) of children with early seizures using whole-exome sequencing in Kazakhstan (CDKL5 (x3), SCN1A (x2), MECP (x2), STXBP1, UBE3A, PCDH19, FOLR1, PNPO).