Learning from atypical development: A systematic review of executive functioning in children and adolescents with the 22q11.2 deletion syndrome

In this systematic review, we investigate executive functioning (EF) in a selected population: children and adolescents with 22q11.2 Deletion Syndrome (22q11DS). Studying a selected subset of the population can inform our understanding of typical development by reducing the etiological variability associated with phenotypic expression of EF. In 22q11DS, EF deficits are, at least in part, the consequence of the deletion on chromosome 22. However, the expression of EF phenotype in 22q11DS varies and is possibly influenced by certain risk factors that occur at increased rates in this population. As such, 22q11DS allows us to study the impact of these factors on EF in the context of one underlying genetic etiology. This review shows that inhibition and shifting are impaired in children with 22q11DS, while updating may be spared in childhood. Notably, EF deficits are found in this population after controlling for intellectual abilities, supporting the hypothesis that EF and intelligence do not reflect the same construct. Current evidence suggests that risk factors previously identified in the general population, such as congenital heart defects or low socioeconomic status, may not impact EF in a similar way in 22q11DS. In the process of demonstrating how studying the 22q11DS population can inform and advance our understanding of EF development, we identify gaps in the literature and highlight opportunities for future research.