| Individuals of either sex with intellectual disability, developmental delay, or autism, especially if they have: |
| Physical or behavioral characteristics of fragile X |
| Family history of fragile X or a relative of either sex with undiagnosed intellectual disability |
| Individuals seeking reproductive counseling with: |
| Family history of fragile X syndrome |
| Family history of undiagnosed intellectual disability |
| Fetuses of carrier mothers |
| Affected individuals or relative in whom the diagnosis was made by cytogenetic studies |
| Women with elevated levels of follicle-stimulating hormone, especially with a family history of premature ovarian insufficiency, fragile X syndrome, or a relative of either sex with undiagnosed intellectual disability |
| Men or women with late-onset intention tremor or ataxia, especially with a family history of movement disorders, fragile X, or undiagnosed intellectual disability |
