Fragile X syndrome (FXS) is a genetic condition that causes a range of developmental problems including learning disabilities and cognitive impairment. Usually, males are more severely affected by this disorder than females. Affected individuals usually have delayed development of speech and language by age 2. 

Applied Behavior Analysis (ABA) therapy is widely utilized and highly effective for individuals with Fragile X Syndrome (FXS), particularly because FXS is the most common inherited genetic cause of autism spectrum disorder (ASD) and intellectual disabilities. Because many individuals with FXS display behavioral features similar to autism—such as communication delays, social anxiety, and repetitive behaviors—the structured, data-driven approach of ABA works well, provided it is carefully tailored to the unique FXS phenotype