Borderline sweat chloride results.

[K360]

Hi I'm writing as I am really worried. I received a letter today saying my sons sweat test results had come back intermediate (basically borderline) but because he had, had a faecal test done aswell which has come back normal the consultant has wrote that this excludes Cystic Fibrosis, and he will discuss it with me when I see him in May?! Should he not be getting him tested again with the sweat test? I don't understand why it was neccerary to do the sweat test if the faecal test ruled it out. My son is 5 nearly 6 has failure to thrive. I just feel like I'm being fobbed off! Has anyone had an experiance like this don't know how I'm expected to wait till May tbh.

Hi.
My daughter has had similar issues.
First tested positive amd had the genetic test which was negative ( although doesn't exclude all mutations)
So repeated sweat test... positive.
Elastase in poo was normal so forgotten about.
At a different hospital. 3 more sweat tests .2 positive one negative.
Turns out she has a probable problem.with glucose storage..still waiting on results but this can cause a false positive
Hope you get some more answers

A normal faecal elastase wouldn't rule out Cystic Fibrosis, though does indicate his pancreas is functioning normally. Pancreatic function can vary in people with CF.
I would certainly push for a repeat sweat test. Does he have any other symptoms?

They should do two sweat tests, what was the result? also some mutations do not cause pancreatic insufficiency so the elastase test will be normal.
Have they done any blood tests?

I know this is a month old but what happened in the end @K360 ?

My son had a result of 45 on his sweat test a couple of weeks back. On Monday they repeated it and I’m just waiting for them to call me about the results. They also took a stool sample.
He is symptomatic, constant chest infections and needs prophylactic antibiotics and has done for a few years.

just has he ever had a blood test to look for CF mutations?

My son had intermediate sweat test results and one mutation was found, he is symptomatic and has been since a toddler.

NK he had a blood test to see if he was a carrier of the CF gene which was negative.
Now his dna is being tested in a different country for rarer mutations, but it’s going to take a few months.

Are you not UK then?
My son had extended genotyping to look for rare mutations, it took about 3 months to come back.

We are in the UK, yes.
Apparently the extensive DNA testing has to happen in a different country, hence the delay in results.

My son had the the most extensive genotyping, his bloods were sent to Manchester.

Brompton have said the test is 98% sensitive but still cannot rule out CF, so with one known mutation, borderline sweat tests, poor weight gain, ABPA, sinus and chest symptoms we are in a grey area.

That's incredibly tough. NK346 :( but the Brompton is the absolute gold standard in CF care so you will get good treatment.
Dd had a second rare mutation and had bloods sent to Manchester but it was 5 years before they found it. ( she did have a positive sweat test though, so was treated as having CF from six weeks)

I wonder if ours has been sent to Manchester.

Our consultant warned us that it would be a few months he also said “I even think it has to go to a different country.”

Then another consultant working for him called me about something else, she had an accent and spoke softly. When she told me the place his DNA was being tested, I couldn’t make out what she said.

In a nutshell, I’ve made an assumption from little information that it’s been sent to another country. Now I wonder if she said Manchester.

I still haven’t had Monday’s sweat test result.
Last time he had the test (Monday as well) they called me on the Friday. So
I’m hoping they call me tomorrow.

Argh I missed the call from the hospital. I’ve asked them to call me again, I hate waiting for results.

bubble they have discharged him back to our local hospital for them to decide how to treat/following him.
Brompton hospital appointment was a bit upsetting as consultant said because of his carrier mutation he has a high chance of being infertile because of CBAVD, I knew men with CF were but didn't realise it could affect carriers too.
How did they find your daughter's second mutation five years later?

just any news?

Yes I just got the call, this time the results were 27 and 28 which is fantastic.

I know it’s not a definitive answer but it’s better at least

NK as I understand they test for the most common mutations first. CF is very predictable geographically and around 80% of people in the UK have one mutation ( my DH carries this). After this they move on to look for the less common mutations but there are so many (around 1800?) of these it can take years :(
As it turns out the mutation I carry is fairly common in certain parts of Europe but virtually unknown here.

justvent that is good news :)