MECP2 and atypical Rett syndrome: Mutations in the MECP2 gene located in Xq28 are the underlying cause of over 90% of typical and a portion of atypical cases of Rett Syndrome (RTT) (Neul et al., 2008; Liyanage and Rastegar, 2014; Chahil and Bollu, 2020), a severe neurodevelopmental disorder that is primarily detected in females (Amir et al., 1999).