Should I be worried after reading about what my brother has on the web?

I read on the web that cystic fibrosis makes you live a short life. My brother was born with it, I believe they never gave him anything for it and now he's 7 and a half years old and when he was check for it, the cystic fibrosis was very low. He has a rare one that didn't go to all the chromosome (if I'm saying/spelling this right) but only like one other person has it. Should I worry after reading about his lifespan after reading this stuff on the web or not? I can't reach out to the doctors and my parents don't like really talking about it, all I know is it's a rare one and all she would have to deal with it in future is allegories