Fibroblast lines have been derived from 22 BP and 10 C patients, expanded and banked to 12 stock vials (or cryostraws) from each patient. From 3 BP and 3 C fibroblast cell lines, we have reprogrammed at least 3 iPSC lines per individual (BP iPSC=28; C iPSC=14). With reprogramming, fibroblast-restricted genes were downregulated (Figures 1a–c; Supplementary Figure 1A) and expression of pluripotency factors was induced (Figure 1d; Supplementary Figures 1B and C). Cells expressing markers of all three germ layers (ectoderm, endoderm and mesoderm) formed following EB differentiation (Supplementary Figure 1D). With differentiation of neurospheres (Figure 1e) followed by neural rosettes (Figure 1f) Sox1, Sox2, Sox3, Pax6 and nestin were expressed (Figure 1g, Supplementary Figure 2). After 4 weeks, neurons with dendrites and axons expressing MAP2, TauAB and β-III tubulin (Figure 1h) formed. Neurons adopted a largely forebrain phenotype, with VGlut+ pyramidal-shaped neurons, GABA+ interneurons, scattered serotonergic and dopaminergic neurons present in the cultures. Many expressed punctate Synapsin1 along their neurites (Figure 1i), with little glial fibrillary acidic protein (GFAP) in the cultures.
