Although others have reported A-T iPSC (Nayler et al., 2012, Lee et al., 2013, Fukawatase et al., 2014), there has been no systematic preparation of a range of ATM mutation sites and no broad assessment of genome stability in iPSC cultures. It is expected that mutations occur spontaneously in tissue culture and presumably even in vivo. We examined several A-T iPSC lines and sublines derived from individually picked colonies for evidence of such reversion. We found that iPSC made from one subject yielded phenotypic and genotypic differences among sublines. Analysis of the resulting isogenic pair of cell lines greatly focuses the identification of cellular mechanisms, such as gene expression differences with or without ATM.
