Medically reviewed by Nicholas R. Metrus, MD Key Takeaways Mosaic Down syndrome has some cells with three copies of chromosome 21, and some with two instead of all three.Only about 1% to 2% of people ...

Teenagers with Down syndrome experience many of the same emotional and hormonal changes as their peers. Their teenage years can also offer the opportunity to expand their functional and social skills.

Fetal alcohol syndrome (FAS) and Down syndrome are both conditions that are present at birth. While they both affect facial appearance, development, and physical health, they have different causes.