FMR1 and fragile X syndrome: Due to the limitations of the methods commonly used for FXS diagnosis, we were unable to detect other uncommon causes of FXS including point mutations, deletions, and duplications which can also affect FMR1 expression and FMRP level; however, during the FXS testing in our study, some available DNA samples of the patients in this cohort were also evaluated using SNP microarray and whole exome sequencing to look for point mutations, deletions, and duplications of the FMR1 gene and other genes that may be associated with ASD in patients.