Which of the following is a commonly associated diagnosis with intellectual disability?

• A. Fragile X syndrome
• B. Spina bifida
• C. Cystic fibrosis
• D. Epilepsy

Answer: (A)

Intellectual disability is often linked to genetic syndromes, and Fragile X syndrome is the most common inherited cause of intellectual disability. The condition arises from a CGG repeat expansion in the FMR1 gene, which reduces the FMRP protein and leads to cognitive delays, learning difficulties, and often autism-like social and behavioral features. Because Fragile X directly contributes to the level of intellectual functioning, it is the diagnosis most traditionally associated with intellectual disability in clinical and exam contexts.

Spina bifida is a neural tube defect with potential cognitive impact in some cases but not a classic, widely recognized association with intellectual disability. Cystic fibrosis is a systemic disease that does not specifically relate to intellectual disability. Epilepsy can occur in individuals with intellectual disability, but it is a common comorbidity rather than a primary associated diagnosis in the way Fragile X is.