Happened to my friend's son. He was diagnosed and passed in less than a year. By the time he left us, it was a relief as weird as it sounds as he was stuck in a chair, unable to move and needed a computer to talk. As he had been a really sporty person before this, it was devastating seeing him go so quickly. We hated what was happening to him but there was nothing you could do and as bad as it was for us, we could only imagine what he was going through. He left behind two sons who now do a lot for charity.
It's something no family should have to go through but it seems his family was there with him at the time which at least is a bit of a comfort.
I often wonder if I was diagnosed with a disease like that, would i just off myself a little while later before things get worse. It's no life, and ultimately things aren't going to improve.
It's no life to live after being a healthy, functioning human, is it. It's incredibly difficult to think about it tbh as nobody wants to think about their own mortality, but in situations like that, what would you do? I can't imagine being in that situation.
As humans we want to continue on and fight to experience more life, but it's not a positive situation. It must be a dreadful kick in the gut to receive such a diagnosis. Processing it must be unimaginable.