Support WBURAn Alzheimer's Drug May Boost Cognition In People With Fragile X SyndromePlay03:34Download AudioJon HamiltonApril 30, 2021 ShareFragile X syndrome involves changes in the X chromosome, as pictured in the four columns of chromosomes starting on the left. The fifth column, on the far right, shows two normal X chromosomes. (Richard J. Green/Science Source)