Thank you Bebop for your comforting support. I know you can understand what it's like to lose a child(or grandchild)-- I'm sorry you can relate.
They are doing an autopsy just like you said-- to see if it was anything genetic. They first did blood tests and everything came out healthy/normal. We haven't heard the results of the autopsy yet.
Thank you so much for your kind reply Bebop-

.... I appreciate you very much.
mandy