For what its worth -- my daughter has one well known severe mutation, and one rare mutation. Research on this rare mutation calls it NOVEL and indicates the "Possibility" of just absence of the vas deferens. HOwever, my daughter is 5. Since age one she has done 4 rounds of IV abx, has a feeding tube despite being pancreatic sufficient, and has x-rays that indicate "peribronchial thickening". Despite the lack of research on her mutation and the speculation that this mutation is one that might not present typically, she has CF, is treated for having CF and will continue to be.