Hello -
I am sorry to say that I do not have any information about this mutation. I just wanted to express empathy as a parent in the same boat - my daughter has one common and one rare mutation (DF508 and S1159P), and there is only one case study that her doctors can find with that rare gene. She was also diagnosed based on newborn screening, had borderline and high-normal sweat tests, and has been asymptomatic so far (at the age of 2). So, I know what it's like, at least, and I hope you find out more!
For what it's worth, our CF center director told me that they are in the middle of merging CFF data with the updated version of the Toronto Sick Kids database, and that they're collecting a lot of information to help them track how things develop for people with different mutations and who receive different treatments. So it may well be the case that when they get all that information stitched together, there will be more for you to go on.