Yeah I have opted to have that at my scan too. It worries me, I imagine it would be low risk and nothing to worry about but you never know and it's good to get a heads up isn't it? My friend has a downs syndrome brother; he's absolutely adorable, very cheeky and fun to be around, but also a lot tougher to look after as in he is VERY strong and if he feels like running away.. he will. constant doors locked and a lot of tantrums. but my friend wouldn't change him for the world, he's a happy soul and we all love him.