Michelle,
There is nothing more empowering and proactive than educating yourself on your son's mutations. In many cases you may have to do single "Google" searches for each mutation. You can learn a great deal if you do independent searches for the mutations on this site as well. There is a spot to search down on the left-hand side. You can do an advanced search over the entire forum. You will be able to find out who has your son's mutations and gauge his prognosis.
I must add a caveat here. It is important to know that every CF presentation of symptoms is different. There are cases of twins with the exact same CF gene combinations and they present symptoms differently. Use the knowledge that you gain as a guide to help figure out what you need to do for him and preventative care. You may be a little sad, depending on what you find, but then again, for me knowing what we might expect was a great coping mechanism for me. It enabled me to put my finger on what we might be expecting AND gave me a sense of control.
I applaude you for making the first step in learning about the mutations your son has. I believe that you will find that when you get the information you seek, it will help you wrap your head around things. I'm sorry I'm not much help with URLs to research, but starting here might be the best option. Other sites get very technical. <img src="i/expressions/face-icon-small-smile.gif" border="0">
Emily