Fragile XE: an important differential diagnosis.

Fragile X is a common cause of mental retardation in boys that can also affect girls. We present the case of a 21-year-old woman with Fragile X E (FRAXE) with learning difficulty, behavioural problems and epilepsy. Her diagnosis was made after investigations spanning several years, highlighting the importance of considering FRAXE and the benefits of reviewing genetic test results in the light of advancing technology.