Roberts, J. E., Hatton, D. D., & Bailey, D. B. (in press). Development and behavior of male toddlers with fragile X syndrome. Journal of Early Intervention.

This report presents findings from a prospective 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 suggested that there is an increase in the developmental skills of male toddlers with fragile X syndrome over time; however, there is a great deal of variability within the sample. Global developmental delays may be evident by12 months of age in some children, but other children may not display delays until later ages. In general, motor skills appear least delayed while communication skills appear most delayed. Standardized in-depth assessments may be more efficient at detecting delays than ratings of clinical impressions, and professionals may be more sensitive to detecting delays at earlier ages than parents.

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