To investigate the effects of different disease-inducing TBL1XR1 mutations, we designed a series of complementation experiments using Tbl1xr1 KO NSCs and lentiviral constructs carrying either Tbl1xr1 WT coding sequence or its mutated versions corresponding to the following human mutations: F10L (case of schizophrenia) (Nishi et al., 2017), G70N (West syndrome-like) (Saitsu et al., 2014), L282P (ASD) (O’Roak et al., 2012) and Y446C (Pierpont syndrome) (Pons et al., 2015; Figure 5A). Here, TBL1XR1 is linked to Pierpont syndrome.