FMR1 and autism: A well-known negative regulator is Fragile X Messenger Ribonucleoprotein (FMRP), which has been shown to interact with the coding region and 3′ UTR of many mRNA transcripts encoding pre- and post-synaptic proteins, many of which were found to be linked to autism (Darnell et al., 2011; Ouwenga et al., 2017).