Just curious. So if my son gets proper nutrition he'd be tall, right? Do genes change because someone in the lineage became short?
No,.if he meant to be short he will be, no matter if you sink him in a bath of milk.
Personally, I was 6cm shorter than my father which is completely normal as I was 11cm taller than my mother. With a short mother is almost impossible to become even as tall as your father.
Now, at 1.76, I am 1cm taller than him.