Nicolaides-Baraitser Syndrome

Never heard of it either, but it could be us. It's a list of symptoms so far, with only a handful of people in the world having them. There is a professor carrying out research and Zack is under further investigation.

If it pans out it would explain more than a few things and give validation, at long last, to the lack of progress on toilet training (I knew it wasn't me).