FXS, which stands for Fragile X Syndrome, is a genetic disorder that can cause developmental delays and intellectual disabilities. Some synonyms for FXS include Martin-Bell Syndrome, a term coined in the 1970s when the disorder was first recognized, and Martin-Bell X Syndrome. Other terms that have been used include Fragile Site, Xq27.3, and FRAXA Syndrome. Regardless of the term used, the underlying genetic mutation in the FMR1 gene on the X chromosome results in a lack of production of the FMRP protein, which is vital for normal brain development. While there may be many names for this condition, the treatment and support for those affected remains the same.