My son had borderline sweat tests 51 & 57, then his initial genetic testing came back negative, which we celebrated. But my husband and I are perplexed. It is so obvious he is malnourished-so many GI problems for a long time. I keep searching for reasons for malnourishment which takes me to pancreatic insufficiency which points to CF. The other things it could be-shwamans, addison's, hypothyroidism, anorexia-(he eats like a horse!) just don't fit. I will of course request the full panel of genetic testing at our next appt., but <i><b>I wanted to know if any of you had experienced an initial negative genetic panel then went on to find mutations in the full panel. </b></i> My son also has mild autism and severe adhd and he has to take large doses of medications for anything to work and then it doesn't last long. We just feel like if he body would start absorbing foods and medications that he will start getting better. He often looks ill and I kind of hope that at our next appt. they will tell us that they want to begin treating him as if he has CF to see if there is an improvement with his health. We will see and I will be sure to keep you all updated.