Effects of Metformin on Individuals with Fragile X Syndrome and Additional Genetic Variants

Background/Objectives: Fragile X syndrome (FXS) is caused by more than 200 CGG repeats in the promoter region of the fragile X messenger ribonucleoprotein (FMR1) located at Xq27.3. While clinical characteristics may vary, most individuals have intellectual disability, speech/language delays, and behavioral disturbances including social anxiety, inattention, hyperactivity, impulsiveness, and aggression. The presence of additional genetic variants is associated with a more severe phenotype in individuals with FXS. Metformin is being studied as a potential targeted treatment for individuals with FXS with studies showing improvements in language and behavior after metformin treatment. This is the first report on the positive benefits of metformin in individuals with FXS and additional genetic variants.