On the other hand, for FCD type I, the number of samples included in the studies is lower and the documented brain mosaic variants targeted a very pleomorphic spectrum of genes and respective biological pathways [STXBP1 (Uddin et al., 2017), AKT3 (Conti et al., 2015), DEPDC5 (Baulac et al., 2015), SLC35A2 (Winawer et al., 2018)]. The gene discussed is SLC35A2; the disease is isolated focal cortical dysplasia type I.