Fragile X mental retardation protein 1 is the product of the gene FMR1, also known as FMRP. This protein binds RNA and is associated with polysomes. FMRP may also be involved in mRNA trafficking from the nucleus to the cytoplasm. A trinucleotide repeat (CGG) in the 5' UTR is normally found at 6-53 copies, but an expansion to 55-230 repeats is the cause of fragile X syndrome. Expansion of the trinucleotide repeat may also cause one form of premature ovarian failure (POF1).