There are three different types of down syndrome
Trisomy 21, translocation, and mosaicism. Trisomy 21 is the most likely kind of Down syndrome to get, mosaicism is the least likely.Down syndrome occurs when there is an extra copy of he chromosome 21. About one in every 700 babies (from the US) has down syndrome.
Some more things about Down Syndrome
Down syndrome is more likely to be inherited then not. Some common physical traits of people with down syndrome are:upward slanted eyes, less muscle tone, and and a smaller structure. Down syndrome people are more likely to get other medical condition. There are no medications or gene therapy for down syndrome.