I don't know that much about it apart from one of DH's friends son has it, and one of my sisters friends has it. The friends son, was diagnosed very young <1, and is fairly obvious their is something wrong with him, he looks a bit different in terms of height (when he was 2 had height of a 4-5 year old - but only the height not any bulk), and features, and has extremely poor eyesight (I think he is around 10 now) - as far as they know there is no family history in his case. He has had various health issues over the years - and his heart and space in his ribcage have to be closely monitored. They are in UK so I have only met him a handful of times, he looks a little different and because of chest issues associated has to be a bit careful about catching colds, and certain activities (I think flying is restricted for some reason) but seems a pretty normal kid. My sisters friend did not find out till in late teens (now early 30's) - I think he suffered a collapsed lung and they found out due to that, but he hasn't really had any other issues - I will check with her.

So I suppose the non-scary angle is that there is a massive range in severity and from the little I know is that I would have thought if any had a more severe form of it that it would have presented by now.