Background: Fragile X syndrome (FXS) and Down syndrome (DS) are the two leading genetic causes of intellectual disability, and FXS is the most common known genetic condition associated with autism. Both FXS and DS are associated with significant language impairment, but little is known about expressive language across domains over time or the role…

State newborn screening (NBS) programs have expanded in recent years, and more tests may be added in the future. The expansion of neonatal screening raises ethical, legal, and social questions. The questions surrounding NBS for fragile X syndrome (FXS) typify these concerns. FXS is an X-linked genetic condition that is the most common inherited…

Purpose: To compare the phonological accuracy and speech intelligibility of boys with fragile X syndrome with autism spectrum disorder (FXS-ASD), fragile X syndrome only (FXS-O), Down syndrome (DS), and typically developing (TD) boys. Method: Participants were 32 boys with FXS-O (3-14 years), 31 with FXS-ASD (5-15 years), 34 with DS (4-16 years),…

Background: Although distinctive neuropsychological impairments have been delineated in children with chromosome 22q11 deletion syndrome (22q11DS), social skills and social cognition remain less well-characterised. Objective: To examine social skills and social cognition and their relationship with neuropsychological function/behaviour and…