| Males | 1 in 4,000-5,000 |
| Females | 1 in 8,000-10,000 |
| Carriers (premutation) | 1 in 250-500 females, 1 in 800 males |
| Global distribution | Relatively uniform across populations |
| Diagnosis | Typically in early childhood (2-4 years) |
| Developmental delays | Apparent by 12-18 months |
| Intellectual disability | Evident in school-age children |
| Life expectancy | Generally normal with appropriate support |
| Databases | OMIMOrphanetClinicalTrialsPubMed |