The hPSC lines used in this study were validated using standardized methods as previously shown26,41. Cultures were tested for and maintained Mycoplasma free. A total of 6 control hiPSC lines derived from fibroblasts harvested from 5 subjects (2 males and 3 females), plus the human embryonic stem cell line H9, and 7 hiPSC lines derived from fibroblasts harvested from 3 subjects with TS (1 female and 2 males) carrying the pG406R mutation were used for experiments (Supplementary Table 1; subjects 7643 and 9862 are from26,41). The TS point mutation in exon 8a of CACNA1C was verified by PCR as previously described41. The hiPSC line H20961 was derived by the Gilad laboratory42. Approval for this study was obtained from the Stanford IRB Panel and informed consent was obtained from all subjects.
