I have a fairly similar story but with my brother; he also had downs syndrome and severe heart troubles, but he lived to 32 years old before his heart gave out. During those years, he got sick with all sorts of other completely unrelated illnesses as well that had huge impacts on his quality of life to the level where you would almost believe that someone had cursed him or something.
So yeah, even if god existed, I would never want anything to do with that megalomaniac psycho.
Not Downs per se I believe, but it very often comes with other complications such as heart problems, like in my brothers case, and that likely causes a lot of troubles with the body that messes with all kinds of things like the immune system and so on.