Previous studies revealed a possible genetic association of MECP2 single-nucleotide polymorphisms (SNPs) with susceptibility to SLE [23,29,31,32,33,34]; moreover, MECP2 rs2734647 is related to other diseases, such as Rett syndrome [35], schizophrenia [36], and aggressive social behavior [37]. This evidence concerns the gene MECP2 and atypical Rett syndrome.