Hi there,My husband was diagnosed w/Delta F508, which pretty much means he was unable to conceive naturally. I was tested for CF and at the time only 25 genes could be tested for and it came back negative. After surgery for him and 8 in-vitro's for me, we were blessed with twin boys. At one year when they tested for lead, I asked them to check for CF. Sure enough, both boys have Delta F508 and one also has S1235R a "polymorph" gene? The doctors asked me to check again for CF, now 5 years after the initial test, and up to 75 or 80 genes could be tested for and it came back positive for S1235R. I don't want to make you paranoid, just get the most accurate testing available.Good luck.....p.s. I'm glad I didn't know because I may not have had these beauties.