Fact about Down syndrome...

Myth: All people with Down syndrome look alike.

False! People that have Down syndrome are as different as you and I are.
...
... Although there are similar characteristics, each person is their OWN PERSON.
"A few of the common physical traits of Down syndrome are low muscle tone, small stature, an upward slant to the eyes, and a single deep crease across the center of... the palm. Every person with Down syndrome is a unique individual and may possess these characteristics to different degrees or not at all."

"She doesn't look like she has Down syndrome." is one of the comments I hate to hear someone say about Miss T. How is she supposed to look? She is her own person and is an individual. Just because she has Down syndrome does not mean she has to look any particular way. She is Miss T. She has Down syndrome; Down syndrome does not have her.

http://www.ndss.org/index.php?option=com_content&view=article&id=54&Itemid=74