WES revealed an SNV within the splice acceptor site of intron 2 in MECP2 (c.27-6C > G, MIM:312750), identical to a previously observed de novo variant in a 5-year-old girl with several features of Rett syndrome, but who lacked deceleration of head growth and exhibited typical growth development [23]. Here, MECP2 is linked to atypical Rett syndrome.