Additional Study Information: Down syndrome (DS) occurs in roughly 1 out of 700 births in the U.S. Half of all children with Down syndrome have congenital heart disease (CHD), often requiring corrective heart surgery. Even though CHD in children without DS is known to be associated with developmental problems, few studies have explored how CHD can affect the development and behavior of children with DS. In this research study, we want to learn whether having CHD and infant heart surgery affects the way children with DS develop and learn. We would like to compare children with DS who have had CHD and infant heart surgery to children with DS who do not have major CHD and did not require infant heart surgery. This information may help us provide better ways to meet the needs of children with DS and improve their development. We are asking you and your child to be in this study because your child has Down syndrome, is between the ages of 5 and 12 years old, and has not had and does not need heart surgery. Eligible individuals will be given a $100 paycard.