Fragile x syndrome

How does the expansion of CGG trinucleotide repeats in fragile X syndrome affect the FMR1 gene?

1: It enhances the expression of the FMR1 gene.
2: It results in the substitution of amino acids in the FMR1 protein.
3: It leads to hypermethylation of the FMR1 gene.
4: It causes the deletion of the FMR1 gene.