Supplementary Fig. 3: Generation of control, MDS, and CTNNA2-mutant stem cells and NPCs.

a, iPSCs and NPCs derived from patient cells are indistinguishable. Patient-derived iPSCs express stem cell markers OCT4, TRA1-81, NANOG, LIN28, and TRA1-60 and form EBs and neural rosettes upon neural induction. Isolated NPCs are PAX6 and NESTIN co-positive. Representative images shown, repeated in three independently generated clones per patient. Scale bar, 50 μm. b, Karyotyping of iPSCs from family 1263 shows normal karyotype after reprogramming. Patients with MDS show a deletion of chromosome 17p11.3 as expected. Karyotyping was performed once for each independently generated clone, for each patient. c, Schematic of CRISPR–Cas9-mediated CTNNA2 mutagenesis and cell morphology and marker expression during neural differentiation. d, CTNNA2^KO stem cells form EBs and neural rosettes upon neural induction. Isolated NPCs are PAX6 and NESTIN co-positive. Representative images shown, repeated in three independently generated CTNNA2^KO clones. Scale bar, 50 μm. e, Chromatograms of the Cas9 cleavage site from three independent CTNNA2^KO stem cell lines used for experiments. Homozygous (clones 1 and 2) or compound heterozygous (clone 3) Cas9-induced frameshift mutations in exon 12 are detected.