The document provides information on Down syndrome, including that it was first identified in 1866, it causes mild to moderate intellectual disabilities, and about 5,000 infants are born with it each year in the US. It discusses the three types of chromosomal abnormalities that cause Down syndrome and common physical features. It also outlines some common health problems, developmental milestones, cognitive and communication characteristics, adaptive skills development, and social/emotional traits of individuals with Down syndrome.