A 16p11.2 duplication means that a small piece of chromosome number 16 is gained in a person. Chromosomes carry the genes that tell our bodies how to grow and develop. Some people are born with extra sections of the chromosomes. Depending on what genetic information is extra/gained, this loss can impact a person’s health, learning and behavior.
These resources all discuss group 1 16p11.2 duplications, as seen in the picture below: