The guidelines for fragile-X test proposed by American Congress of Obstetricians and Gynecologists (ACOG) and American College of Medical Genetics (ACMG) [1, 3] recommend that this test should be performed in individuals with a personal or family history of fragile-X, fragile-X-related disorders, unexplained mental retardation or developmental delay, autism, ovarian insufficiency or elevated follicle-stimulating hormone before 40 years old of unknown cause. Here, PSMB5 is linked to Global developmental delay.