Adaptive Skill Trajectories In Infants With Fragile X Syndrome

This study examined longitudinal trajectories of adaptive behavior in infants with fragile X syndrome (FXS), compared to typical development (TD) and infant siblings of children diagnosed with autism (ASIBs). Additional analysis were conducted to examine the differences in trajectories for males and females with FXS, and to identify if a profile of strengths and weaknesses appeared across domains by 24 months in males with FXS. Participants included 76 male infants assessed up to 4 times between 6 and 24 months of age. A sample of 12 females with FXS was also included for the comparative sex analysis. Infants with FXS displayed lower initial adaptive behavior across all domains, and slower growth rates than both comparison groups. Differences in initial status and growth rates were different between males and females depending on the domain measured. No significant profile of strengths and weaknesses was identified in infants with FXS at 24 months.