• Article

Development and behavior of male toddlers with Fragile X syndrome

This report presents findings from an ongoing longitudinal study of the developmental and behavioral characteristics of 26 boys with fragile X syndrome between the ages of 12 and 36 months. Multiple measures and analyses were used to describe the characteristics of these boys. Results indicated that there is an increase in the developmental skills of male toddlers with fragile X syndrome over time, although there is a great deal of variability within the sample. Global developmental delays might be evident by 12 months of age in some children, but other children might not display delays until later ages. In general, motor skills appear least delayed, whereas communication skills appear most delayed. Standardized in-depth assessments might be more efficient at detecting delays than ratings of clinical impressions, and professionals might be more sensitive to detecting delays at earlier ages than parents.


Roberts, JE., Hatton, DD., & Bailey, D. (2001). Development and behavior of male toddlers with Fragile X syndrome. Journal of Early Intervention, 24(3), 207-223. DOI: 10.1177/10538151010240030601