WNT1 and Fabry disease: The present study complements our initial characterization of the Wnt1-Cre; Elp1LoxP/LoxP CKO and provides insight into why PNS development is stunted in this model; our data show that perturbations in Notch signaling likely attenuate progenitor proliferation, a scenario that may contribute to reduced peripheral neuron numbers in FD children as well.