Down syndrome is a genetic condition caused by the presence of an extra chromosome 21. It is associated with cognitive impairment and physical birth defects. There are three main types of Down syndrome: Trisomy 21, Mosaic, and Translocation. Prenatal testing can detect Down syndrome but about 90% of women receiving a positive result choose abortion. While there is no cure, early intervention and lifelong care help people with Down syndrome achieve their full potential and live fulfilling lives.