R75x ?

Amy Galm

New member
I know I am not alone in being the parent of a child with "suspected" diagnosis since birth.

My son has had negative sweat tests - he had a Genzyme test done in 2008 (when he was 5) and it came back with benign variants

So what we know is that he has two very common, benign sequence changes T845T and Q1463Q. I have read that his 3rd R75X can be disease causing BUT he has only been found to have these.

He has no pancreatic symptoms that we know of. His PFTs always show obstructive lung disease. He has been on Pulmozyme and the airway clearance vest.

He has been pretty healthy for the last few years and now again - chest is filled with mucus.

Every time Pulmo does a bronchoscopy - she says the mucus is so thick, she can't even get any out!

I am just worried that we are not doing enough.

Does this mean that he is a carrier? Does this mean that he is A-typical or does this mean he may have a rare mutation that has not been studies yet?

BTW he is 11 years old.

Thanks so much.



Hi Amy!

Welcome! There are other participants here that are far more educated in the genetic and scientific aspects of cystic fibrosis than I am -- I hope they will chime in...

My take on a carrier is that a carrier has one copy of the required two copies of the gene(s) that would cause a person to actually be impacted by the disease... I think the classic definition of a "carrier" is that the person can pass on the disease -- but does not have or show any symptoms of the disease... If they conceive with another carrier, and both copies of the particular gene pair off -- the child would actually have the disease... All CF patients are carriers -- your son may or may not be a carrier, but the bigger issue is that he appears to have some symptoms and may actually have CF, or some mutation of CF, or some other type of respiratory disease...

Atypical simply is something that is not-typical -- your son appears to fit into that category at this moment... Whether he has some yet-to-be-discovered mutation of CF, or the "benign variants" aren't really so benign -- he seems to qualify under the atypical description...

I know that others will chime in with more detailed answers... I hope he's doing OK.

Love, Steve