Family Study of Fragile X and Down syndrome

Children diagnosed with Fragile X syndrome and Down syndrome are at substantially increased risk for developing neuropsychiatric disorders including autism spectrum disorder (ASD) and attention-deficit hyperactivity disorder (ADHD). Despite a known genetic cause for each syndrome, substantial clinical variability exists among children with both syndromes, suggesting an important role for genetic background in shaping child outcomes. We will collect behavioral and genetic data from biological parents to model the relative role of genetic background in explaining behavioral, neurobiological, and clinical variability in young children with Fragile X and Down syndrome who have been followed with brain imaging and behavioral testing since infancy.