When someone has three chromosomes on chromosome 21, it means you have Down syndrome. I know the genetic mutation in the photo is Down syndrome because when three chromosomes are present, people tend to use the term "trisomy", also known as Down syndrome. Down syndrome is a genetic disorder that affects not only the child or person who has it, but everyone. Down syndrome is a genetic mental and physical disorder that is very hard on anyone. Down syndrome is a disorder that is accompanied by certain defects, including facial, heart, vision and hearing, and other health problems. It is also the most common genetic abnormality, affecting many babies. Down syndrome is caused when chromosomes are divided during meiosis. The cell retains both copies of chromosome #21, meaning that the person with Down syndrome has an extra copy in every cell in their body. This is a sad genetic disease that can change a person's life. Even though it's a devastating genetic mutation, people with Down syndrome are some of the most loving people....