For the four families, we differentiated two to three iPSC lines per person into organoids using a modification of our free-floating tridimensional (3D) culture method (Mariani et al., 2012) (see schematic outline in Figure S3A). Similarly to our previously published preparation (Abyzov et al., 2012; Mariani et al., 2012) and to other protocols described in the literature (Eiraku et al., 2008; Lancaster et al., 2013) we obtained organoids characterized by autonomously organized layers of radial glia, intermediate progenitors and neurons (Figure 1; Figure S3C, D).
