My husband was diagnosed with CF at age 59. This was back in the late 90s. One of our granddaughters was diagnosed shortly before that, while she was in the hospital for an upper respiratory infection. Knowing that CF is a genetic disease (no one in our family had ever been diagnosed before now), I did some research using some of the various digestive & respiratory problems that my husband had experienced most of his adult life. I contacted the Nat'l CF foundation for information. They gave me the names of several adult clinics and I contacted the one closest to us (St Louis University). We were set up for a consultation with the Doctor in charge. Fast forward - went to appointment, discussed medical history, Doctor agreed to "Sweat test", but stated that she did not think he would be positive. Sweat tests (3) were done at Cardinal Glennon Hospital. Two of the tests were border line and the 3rd was positive. After the diagnosis we came back home and held a family meeting (he has 8 siblings) gave the news and encouraged them to contact their family medical providers. Five of his siblings decided to be tested, 1 was positive and 2 were border line. Both my husband and his sibling have had serious on going medical problems related to CF. Genetic research has identified the gene connected to CF, however there are over 1500 (maybe more) mutations that contribute to how the disease is manifested in each individual. From the reseach my husband has done, he has concluded that in his situation, the gene does not impact the early growing years in the same way as it does in the later years. Early on he was small for his age, had salt deposits on his skin after perspiration, with asthma, lots of upper respiratory infections. However, as he advanced in age he began to develop gastro problems, more serious lung problems, along with heart & liver problems. The mutation n his family really seems to turn on as they get older. He sees several medical specialists on a regular schedule primary doctor, cardiologist, pulmonologist and gastroenterologist, as needed. The adult clinics have been very helpful. I hope this helps to answer your questions.