In a mouse model of Rett syndrome (global MeCP2 gene knockout), sensitivity of brainstem astrocytes to changes in PCO2/pH is markedly reduced (Turovsky, Karagiannis, Abdala, & Gourine, 2015) and ventilatory CO2 sensitivity is severely impaired (Bissonnette, Schaevitz, Knopp, & Zhou, 2014). This evidence concerns the gene MECP2 and atypical Rett syndrome.