One of the biggest mistakes of people is assuming that Down Syndrome and Autism are the same. These are two different types of conditions that may affect people from all over the world. Down Syndrome is usually caused by Trisomy 21, which means there are three copies of chromosome 21 as compared to the usual two copies that people may have. Some people who have down syndrome are also diagnosed with autism.
Autism, on the other hand, has no known cause yet. There are some studies and researches about it, but there are not enough details that will prove if there are actual causes of getting this condition. There are some people who are saying that more and more people are being diagnosed with autism, probably because people are more aware of it now as compared to before.