SLC12A5 and atypical Rett syndrome: This result fits with the recovered transcriptional levels of Kcc2, the neuron‐specific K+‐Cl− co‐transporter (KCC2) that is crucial for GABA signaling maturation (Ben‐Ari, 2002; Ben‐Ari et al,2007) and its normalization in Rett syndrome currently represents a promising therapeutic approach (Tang et al,2016; Hinz et al,2019; Tang et al,2019; Lozovaya et al,2019).