To assess whether the length of the pathological CAG repeat in GABAergic neurons derived from HD-iPSCs is affected during lentiviral reprogramming, a study was conducted showing that neither the long-term growth of reprogrammed HD-iPSCs in vitro nor the differentiation process affects the lengths of CAG trinucleotide repeats in these neurons (Camnasio et al., 2012). In this study, the neural differentiation protocol described by Chambers et al. was used (Chambers et al., 2009), where it is shown that the synergistic action of two SMAD signaling pathway inhibitors, Noggin and SB431542, is sufficient to induce rapid and complete neural differentiation. These advances in the use of HD-specific iPSCs and neurons differentiated from them may provide a powerful platform for target identification and drug screening in HD.
