Truncating variants of the "MAGEL2" gene, one of the protein-coding genes within the Prader-Willi syndrome (PWS) critical region on chromosome 15q11, cause Schaaf-Yang syndrome (SYS)--a neurodevelopmental disorder that shares several clinical features with PWS. The current study sought to characterize the neurobehavioral phenotype of SYS…

This study compared maternal responsiveness to children with two neurodevelopmental disorders sharing different but, in some cases, overlapping social phenotypes--Williams syndrome (WS) and autism spectrum disorder (ASD)--and explored the relations between maternal responsiveness and child emotional/behavioural problems (EBP). The sample included…

Three levels of investigation underlie all biologically based attempts at classification of behaviorally defined developmental and psychiatric disorders: Level A, pseudo-categorical classification of mostly dimensional descriptions of behaviors and their disorders included in the 2013 American Psychiatric Association's Fifth Edition of the…

Chromosomal microarray analysis (CMA) has emerged as a powerful new tool to identify genomic abnormalities associated with a wide range of developmental disabilities including congenital malformations, cognitive impairment, and behavioral abnormalities. CMA includes array comparative genomic hybridization (CGH) and single nucleotide polymorphism…

There is a very substantial literature over the past 50 years on the advantages of early detection and intervention on the cognitive, communicative, and social-emotional development of infants and toddlers at risk for developmental delay due to premature birth or social disadvantage. Most of these studies excluded children with severe delays or…