This gene encodes a putative transcriptional activator that is a member of the AF4FMR2 gene family. This gene is associated with the folate-sensitive fragile X E locus on chromosome X. A repeat polymorphism in the fragile X E locus results in silencing of this gene causing Fragile X E syndrome. Fragile X E syndrome is a form of nonsyndromic X-linked mental retardation. Alternate splicing results in multiple transcript variants.