Belly buttons are funny things aren't they?
Kayla has an 'outie' button - she is the only one in our family of four who is an outie. (And Lucas is the only one in our family who writes with his left hand; so they each get to be unique!)
Over the years I have noticed several children with Down syndrome who also have outie belly buttons.
I don't think there is any connection to whether your belly button is an 'innie' or an 'outie' and Down syndrome, but I am curious to see if there is a majority one way or the other. And maybe having low muscle tone affects how the belly button is formed? I have no idea.
So here is my very unscientific, out-of-curiosity, just-for-fun, internet poll about belly buttons and Down syndrome.