However, there is an association of Fragile X syndrome (FraX) and autistic spectrum behavior, which is found in 50%–65% of boys and 20% of girls with FraX.2 FraX has an approximate prevalence rate of 1 in 5 000–8 000 females and 1 in 4 000 in males and is a significant monogenetic cause of autism.3 FraX results from absence of expression of the FMR1 protein (FMRP) due to excessive trinucleotide (CGG) repeats in the Fragile X Messenger Ribonucleoprotein 1 (FMR1) gene,4 with >200 repeats leading to a what is known as full mutation, or absence of the gene product. Here, FMR1 is linked to autism.