Meet the Other Phone. Protection built in.

Meet the Other Phone.
Protection built in.

Buy now

Please or to access all these features

Children's health

Mumsnet doesn't verify the qualifications of users. If you have medical concerns, please consult a healthcare professional.

Cystic Fibrosis concerns, despite negative newborn screening

38 replies

Caterpillar05 · 08/07/2025 22:42

Hi all, hoping for some advice or shared experiences.

Apologies, this may be a bit long winded but wanted to give as much context as I could.

My 3yo had a negative NBS for CF, but he’s had ongoing respiratory and GI issues since birth. Even when he’s well he will cough up mucus (just a lot less than when he’s unwell), usually when/after he’s running around.

Sorry TMI but it’s relevant - He’s had frequent mucus in his stools since newborn stage and still does, I’m talking almost every nappy. He has oily nappies sometimes too… he still goes in a nappy for number 2s because he’s afraid of going in the toilet, it takes him soooo long to go, bless him! They are very bulky, mushy, often extremely foul smelling (and foul smelling gas too, he could clear out a room full of adults!), sometimes with diarrhoea. He would suffer from constipation too but not severely, as in it sorts itself out. His stools have worsened recently (past month), ranging in the colours yellow/a paler yellow, orange/light tan, dark green, very dark brown/black (just the last 2 days - sticky consistency, like tar). I’m worrying this may be a sign of pancreas insufficiency. He’s still a healthy weight for his height and age but it looks like he’s lost some weight to me. I’ve weighed him but don’t have a weight from previous to compare him as we’ve never felt the need to weigh him before.

He’s had repeated respiratory infections, 2 hospital admissions (1 needing oxygen support during sleep), and countless A&E visits, mainly due to rapidly increased breaths per minute and a persistent, productive cough and coughing fits. Doctors have heard wheeze and crackles before, but sometimes another doctor won’t hear anything, usually not long after he’s just coughed, so I assume he’s cleared mucus. A chest x-ray at 20 months during his 2nd hospital admission, showed slight infection, but a follow up showed clear.

His skin is extremely salty (like sea water, especially his head), I understand it’s normal for sweat to taste somewhat salty but this is constantly - even when he’s not sweating and to the effect that even when I was giving him loads of goodnight kisses tonight, it left me with wrinkly feeling lips, the way they’d feel if you’d got too much salt on them, which has me concerned since a 1st and also a distant cousin has CF. Though his dad (my partner) and his sister who’s child it is that has CF have different dads, so we aren’t even sure what side the CFTR gene has came from and I’ve never had any reason to have genetic testing for anything CF related so unaware if I’m a carrier or not - same as his dad.

He was diagnosed with a CMPA as a newborn and was on Neocate for 1+ years, but his GI symptoms never fully improved, he just seemed happier in himself and he’s never had failure to thrive, so when I’ve mentioned this fact, it’s always been dismissed as there was some improvement. He’s finally been referred to a respiratory consultant, after being told he would be referred to the viral wheeze clinic at 16 months and again at 2.5y, but the referrals were never sent. His appointment is with a respiratory consultant that specialises in CF, and a sweat test will also be arranged.

In the meantime, I’m not sure whether I’m just having a bit of health anxiety over it or if I’ve genuine reasons to believe CF might be a possibility so I’m just wondering if anyone’s experienced a false negative NBS and their child has went on to be diagnosed with CF as a toddler, or if they know anyone that’s went through a similar situation and they would be willing to share their experience and the outcome.

Thanks in advance!

OP posts:
heatherwithapee · 09/07/2025 07:21

No personal experience but a child at school with my DC was diagnosed with CF in early primary school. I would assume they’d been tested as a newborn as the mum mentioned ‘it had been missed’ before. Child had similar symptoms to your child. They then tested the siblings (who weren't as symptomatic) and another brother was diagnosed with it too.

Good luck with the appointments and tests and hope you get some answers.

TheQuietestSpace · 09/07/2025 07:24

False negatives are definitely a thing with CF. Trust your gut and ask the doctors to check - I was about to say that the worst that happens is they say youre wrong, but actually the worst thing would be not to get checked and thus not get the support he might need.

Sweetiedarling2024 · 09/07/2025 07:25

Speak to the CF trust, my friend works there and they’re very helpful x

Caterpillar05 · 09/07/2025 09:13

@heatherwithapee- sorry if this isn’t directly replying to you… it’s my first time posting and I’m still getting use to how to use this lol!

I had read online that it’s definitely possible to be ‘missed’ but that it was very rare so I was wondering actually how rare it was. I have ADHD, so of course I was researching statistics etc and have been telling myself there’s no way he would be unfortunate enough to possibly be one of those statistics 🫣

It’s funny you say that, my older child will go a while without coughing but then develops a persistent productive cough. When I say persistent I mean it goes on for months! GP suspects she has asthma. Thankfully never unwell enough to warrant hospital. No other concerns, aside from they would have slightly salty skin too but nothing that I would consider abnormal and they have different dads.

Thank you for the well wishes!

OP posts:
Caterpillar05 · 09/07/2025 09:29

@TheQuietestSpace- I got an appointment with the GP this morning, just due to how salty his skin is at the minute, he’s also got very strong smelling urine and with how his stools are, I’m quite concerned about him getting dehydrated!

I’ve had to advocate so hard when it’s came to his health without ever really getting any answers. If anything serious can be ruled out I will be happy and reassured but up to this point, I’ve never felt truly reassured and just told myself that I was overreacting.

OP posts:
Caterpillar05 · 09/07/2025 09:37

@Sweetiedarling2024- I’ve spoken to them before as I know they are great help to my niece (she’s only 1) and her parents and I’m in regular contact with them due to fundraising for them. Unfortunately, aside from general advice they couldn’t really provide much more information, which is understandable. I didn’t really know the right questions to ask though!

Thank you for the advice ☺️

OP posts:
Geneticsbunny · 09/07/2025 09:39

Go to your gp and ask for a referral to clinical genetics. Explain what you are worried about and why. I think you have a good case for asking for further testing. You could also ask for the results from the newborn screening test, they could show that your child has one cf mutation in which case that is extra evidence to suggest they should do more testing to look for second mutation.

thrive25 · 09/07/2025 09:53

@Caterpillar05 : you are right to get (re)tested as these are all classic symptoms (which an adult CF patient I know) had as a child

OtterMummy2024 · 09/07/2025 11:46

You need to tell the GP that there are CF cases in cousins, that raises the chances/clinical suspicion. From the CF trust website, the newborn testing does not screen for ALL known CF mutations, only the most common. If you know which mutations the cousin has, this might speed up testing from Clinical Genetics too.

OtterMummy2024 · 09/07/2025 11:48

The rare mutations can also present with milder or atypical symptoms. My housemate at uni had an usual combination of mutations that meant he had relatively good lungs but more digestive issues.

Back20 · 09/07/2025 12:14

It’s not genetics you need at this stage. Tell them you require a sweat test. I’d be contacting PALS TODAY.

Cauliflowercheeses · 09/07/2025 15:40

My son was diagnosed via sweat test. If he’s salty and frequently oily stools then they’re definitely symptoms. If it’s in family then sounds like you really need this ruling out or confirming.

CF isn’t what it used to be, you just have to get the treatment. Also agree, CF trust was amazing with us.

sending love. X

GrimlyPinemarten · 09/07/2025 15:56

I have a child with CF. Severe CF. She has all the symptoms you prescribe. Or did have, before the miracle drug that is Kaftrio. 🙏🙏🙏

Caterpillar05 · 09/07/2025 17:04

@Geneticsbunnythank you - GP has already referred recommending a sweat test to be carried out but I assume genetic testing will also be arranged if they have any concerns.

I requested his NBS results as you recommended and they just rang me there to say that they’ve printed them off for me to collect tomorrow.

Thank you for the advice ☺️

OP posts:
Caterpillar05 · 09/07/2025 17:06

@OtterMummy2024GP is aware and mentioned this on the referral to Paeds. Referral has been accepted but not until next month. I will have to ask which mutations my niece has as I forget. Thank you for the advice ☺️

OP posts:
Caterpillar05 · 09/07/2025 17:07

@Back20GP recommended in the referral letter that a sweat test be carried out, so I assume that this will be arranged when we see the consultant next month 🤞🏼 thank you!

OP posts:
Caterpillar05 · 09/07/2025 17:15

@Cauliflowercheeses do you mind me asking what age your son was when he was diagnosed? We visited the GP this afternoon as his symptoms are worsening (being super salty and having strong smelling pee), and I’m quite worried he’s losing more salt than he should. Also, his stools are like ones I’ve never seen in my life! GP has sent us to A&E to be assessed properly.

CF Trust really are amazing with my niece and her parents ☺️

Thanks so much for replying x

OP posts:
Caterpillar05 · 09/07/2025 17:18

@GrimlyPinemarten bless them! My child has never been ‘severely’ sick and due to his cousin having classic CF, I sometimes feel like I may just be being overly anxious due to family history.

I’m glad your child has access to Kaftrio, it really is life changing. My niece is on Orkambi 🥰

OP posts:
Caterpillar05 · 09/07/2025 17:20

@OtterMummy2024 I had noticed that had came up a few times when I was doing some research! Sounds the same as my child’s but I’m also aware of the fact that his symptoms also overlap with some other medical conditions. It will be good to have some answers 🤞🏼

OP posts:
Cauliflowercheeses · 09/07/2025 17:44

Mine was twelve weeks. He had no symptoms at all but was just losing weight and really bad nappies. It was the worst twelve weeks of my life. At one point I think the HV thought I was neglecting him as he was losing weight every week.

it took a very sympathetic GP who referred us immediately to Alder Hey. The test was done that day and confirmed by blood test a week later.

he’s now 20 years old, 6’4 doing well at uni and never had a days sickness in his life thanks to early diagnosis and getting him on the right treatment.

If you have it in the family then i am sure you know all about it and have plenty of support so please push for a test then you know either way. Xx

Back20 · 10/07/2025 12:20

I’ve been thinking about you @Caterpillar05. Do you have someone to take with you to the appointment?

Caterpillar05 · 10/07/2025 16:43

@Cauliflowercheeses Bless him! My child has never had any issues with his weight, he was a big chunk!! No doctor would take me serious that something must be underlying to cause all the symptoms he was experiencing as a newborn/baby. Every nappy was an explosive one so I’ve no idea how he didn’t lose any weight! But then again, he was always hungry so it kept his calories up 😂 how upsetting though, that you were made to feel that way.

I’m so glad that you finally got someone that was willing to listen to your concerns as it seems to be very far and few between who will truly listen, it makes you feel like you’re being overly dramatic when it comes to having to advocate for them sometimes, doesn’t it?! 😔

Even more amazing that your son is continuing to do so well through life. CF drugs are truly miracle drugs!

As my son doesn’t show the classic CF signs or should I say severity of them then surprisingly when I’ve mentioned to family I’ve been made to feel like my concerns aren’t valid and his symptoms HAVE to be down to something unrelated because he would’ve been extremely sick by now if he did have CF, especially with be around my niece due to the distance rule. While I really hope and pray that it isn’t CF or CF related, and I appreciate that his symptoms can overlap those of many other common conditions such as asthma/allergies etc, it just makes me feel really stupid for even wanting to rule the worse case scenario out. Thank you for your advice 🥰 x

OP posts:
Caterpillar05 · 10/07/2025 17:08

@Back20 His dad should be able to get out of work to come with me but if he can’t then I’m happy to go on my own anyway.

As I mentioned in my previous reply to another comment above, I’ve been made to feel silly by family for having these concerns, they even said that ‘we know he doesn’t have CF’ due to neg NBS and as his symptoms aren’t severe but I know every CF patient is different! I’m just grateful that he’s never been severely sick and I’m also lucky enough to know to listen to my mothers instinct over the input of others. Even though it’s unlikely, it’s not impossible so I will still go ahead with ruling the worse case scenario out, knowing that I will have done my part as his mother. Thank you for thinking of us x

OP posts:
Back20 · 10/07/2025 18:23

I would try and make someone goes with you. It’s much easier to fob you off if you’re on your own. Good luck xx

Caterpillar05 · 11/07/2025 16:50

@Back20I’ve learnt how to advocate for him over the years due to how many times we were fobbed off when I always turned out to be right in raising my concerns, thankfully! Thank you 🥰 xx

I actually watched salt crystals form before my eyes on his skin today after he started to cool down from being in the car! He sweats a lot as it is but he fell asleep in the car and he sweats more when he’s sleeping. I had the AC on full blast which is really cold and all the windows down when driving etc but just being cooped up in his car seat he still got warm. I brought him up to our bedroom as it’s nice and cool (my house is like a sauna in the warm weather) and stripped him down to his boxers then within a few mins once he had started to cool down I noticed these white things on his face and neck, then the back of his knee and just watched them form all over his leg and arm from there. I even wiped them away in case it was crumbs of something but they reappeared! It was actually quite worrying 🤯

OP posts:
Swipe left for the next trending thread