CF pathogenic mutation 3120+1G>A homozygous

Hello
I am mother of 16 year old patient who suffers from cystic fibrosis. The diagnosis was proved by the genetic analysis which was made in Germany, when the patient was 14. The pathogenic mutation is 3120+1G>A homozygous. The patient does not suffer from the symptoms peculiar to the cystic fibrosis, he just has Bronchoectazy in the upper part of the right lung.
My son recently suffers from periodical temperatures and we made bacterial research and found out that there was pseudomonas aerugenosa 103. The doctor started aggressive treatment with the combination of two antybiotics – Roxipime (4 gr. daily Intra vein) and Amicacina (2 gr. daily intra vein) during 10 days. Now the patient does not cough, the phlegm totally disappeared (though phlegm was a bit only in the morning).

I am interested if anybody in this group has the same mutation (3120+1G>A homozygous) or you may have any information about the patients suffering from the same mutation of the disease.

Any information will be really helpful for me...