“…A number of studies have highlighted the importance of education and medical care in the development of people with DS (Buckley, Bird, Sacks, & Archer, 2006;Couzens, Haynes, & Cuskelly, 2012;Hanson, 2003). Although comprehensive health assessment programs have improved health outcomes among people with intellectual disability (Cooper et al, 2006), many adults with DS still do not have access to regular health care, despite the high frequency of medical complications (Henderson, Lynch, Wilkinson, & Hunter, 2007;Määttä et al, 2011). The variability we found can also be attributed to epigenetic factors, such as allelic variation and genomic imbalance (Lott & Dierssen, 2010); and we can surmise that the complexity and variability of geneenvironment interactions play a decisive role in cognitive changes.…”