The median life expectancy for a child with Down syndrome (DS) born in the 1950s was less than 10 years of age, with congenital heart defects being the main cause of death.1 With advances in medical care and improvements in the overall health of individuals with DS, life expectancy has increased dramatically; for children with DS born in 2010, median life expectancy is estimated to be 65 years.2 However, along with this longer lifespan comes the prospect of a considerable increase in the risk of developing dementia associated with Alzheimer disease (AD), with a prevalence of nearly 80% for those with DS who are older than 65 years.3