Figure 1.

The Genetics of Human FXS versus Mouse Models of FXS

(A) The human FMR1 locus contains several primate-specific lnRNAs, FMR4, FMR5, and FMR6. ASFMR1 exists in both humans and mice. In FXS-affected individuals with a full mutation, most of these lncRNAs are also silenced.

(B) Mouse models of FXS have been created through the insertion of a neomycin cassette into exon 5 (KO1) or the deletion of the promoter and exon 1 (KO2), leading to a lack of protein production in both KO1 and KO2. ASFmr1 expression is unknown in mouse models.