In patients with Fragile X syndrome, a CGG trinucleotide repeat located in the 5′-UTR of the fragile X messenger ribonucleoprotein 1 (Fmr1) gene expands from ~50 to >200, resulting in hypermethylation of the promoter region and epigenetic silencing of the Fmr1 gene [4–7]. This evidence concerns the gene FMR1 and fragile X syndrome.