Test Result




I received a full sequence result for my 16 month old son today. The result reads he is heterozygous for;c.1521_1523delCTT (p.Phe508del), andc.1584G>A(p.GLu528Glu) mutations.They also found sequence variants of limited or no known significance;c.744-31TTGA[5]+[6]c.869+11C>Tc.1210-12T[7]+[9] (PolyT 7T/9T)c.1766+152T>Ac.2562T>Gc.2909-92G>Ac.3469-65C>Ac.3874-200G>AThe genetics speacialist advised this did not show a CF diagnosis and we would have to wait and see if his symtoms persist. He has had ongoing symptoms of diareah, daily cough, constant sinus issues, too many URI to count (11 courses of antibiotics in 12 mths), waitng for surgery to remove his adenoids. Because he has constantly passed a sweat test and is putting on weight they don't think it can be CF. My 6 old son is currently seeing a GI for weight loss as he has had poor weight gain and even recently lost weight. He dropped from 75 percentile to 10 percentile (and eats every minute of the day), floating stools, and has had a constant cough since he was three. He always has low iron levels and has had one boute of pnemonia. He passed his sweat test at 28 so he has had no genetics testing as yet. I was hopeing someone could help me with the result as my gut keep telling me its CF. I was aware of our family history of CF as my neice has DDF508 and my eldest daughter is a carrier but has absolutely no symptoms. My other daughter is also a picture of health. Can anybody PLEASE help?Concerned mumI


I'm sorry for your struggles... I was diagnosed at age 40 via genetic testing (DF508; D1152H: considered to contribute to milder sxs) I had two sweat test, both were negative. I am pancreatic sufficient but have had significant sinus and lung issues all my life with multiple pneumonias. My FEV1 is 56% and I have pseudomonas. If I I were a child today I have a feeling I'd be in the same situation as your son. Follow your gut. If treatments were available to me as a child I think a lot of permanent damage could have been prevented. Good luck!


Thankyou for your reply. The mutation is better known as 1716G/A. Yes I know it is all related somehow and only want to be proactive. According to the geneticist being proactive has no effect on longevity. Clearly she does have full comprehension of this disease. Her opinion is diagnosis or no diagnosis we would only treat the symptoms as they arose. She is saying as there is no other person known to be effected by these two mutations, we have to wait and see if his symptoms persist. For me as A mother, that is not good enough. Thanks again.


New member

We were in a similar boat two years ago. My son is completely PI (enzyme side) but passed a sweat test and only has one known mutation. He did receive a diagnosis almost two years ago. Treatment has helped so much. The enzymes allow him to digest food. He still has iron issues (had a hemoglobin of 6 and ferritin of 1.8 at 2 years old) but is doing much better. We are having duplication/deleation tests performed in Sept. My suggestion, if you are not happy with with the genetics/doctors are saying, get a second opinion. We were told he definately had a rare genetic disorder, but that it was not CF and not schwachman diamond, and probably not known at that point. It took finding the right CF doctor who recognized his symptoms and knew his mutation to make our diagnosis. Johns Hopkins is a great place for that and I am sure there are many others too. Good luck and our prayers are with you.


New member
Hello Justin's mom, CF can be mild in some people and more severe in others. I'm and adult who had URI's, bronchitis, and poor weight gain..all of my childhood. No one ever looked for CF. I got diagnosed when I was 30. By then the damage had already been done to my lungs, sinuses etc. I take pancreatic enzymes and now have to work from home, due to my health. I would recommend getting a second opinion. I think that sometimes you need treatment to be preventative to avoid more damage happening later in life. I am always on preventative antibiotics and do daily breathing treatments, take enzymes etc.--all of this is preventative type of stuff that does work. I have not had an infection that required IV antibiotics for about 6 months and that is great for me. I also feel better and have more energy since I do all my treatments. Even if your kids don't have CF they could be carriers and still have some symptoms of CF. They could also have some type of primary immune deficiency, immune deficiencies can look a lot like CF. I will keep your boys in my prayers. Sue, adult w CF, age 40 and mom to 3 adopted kids no CF :)


Super Moderator
God I love throwing spitballs at medical tests. I feel that way sometimes because I am in a field where I especially understand a genetic test. The test itself is fine, how we interpret and explain these test results is about as variable as the person doing it. A recent topic post cited an article about 105 additional errors found to cause CF is a great example of what we do know about CFTR genetics. My first read of the article made no sense in part because I believed there were more vetted CFTR mutations, certainly by now!

The post went away before I could respond but after a serious reading of the article it is clear that only 127 of the 1900 known CFTR mutations have been established as causing CF. It doesn't mean that only 127 mutations have been looked at, many have been dismissed as not causing CF. Some of these are well tested, most have a clever way of saying nothing. "This mutation is not known to cause CF" is completely different from "this mutation is known not to cause CF".

Don't turn lose of that gut feeling. CF ultimately is just a label, how your children are treated and the medical protocols may be the same as genetically confirmed CF. Accept no less if this is what they need. I have yet to meet a CF specialist who doesn't lock onto a genetic test for CF just enough to give the patient and family some doubt. Then they blow past it and treat the issues without mentioning that they really don't care about the test unless there is a drug to help. If doctors understand that being told what you don't have is worthless when you want to know what IS wrong, they are expert at hiding it. I am too good natured to genuinely incriminate a litany of doctors who missed my CF for fifty-two years, and there is good reason.

The first time I saw the term Cystic fibrosis Related Metabolic Syndrome (CRMS) a new sub-category of CF, I could just see me pigeon holed there. After taking stock of what and why this was done it made very good sense. Many of the CFTR mutations are extremely rare and many genetically confirmed CF “patients” are found to be free of symptoms. Even the most pernicious of mutations may never develop symptoms or seemingly turn on later in life, be it four or forty. CRMS is like a storm watch over a storm warning, sort of a holding area to be carefully monitored for developing CF issues.

My presentation of CF has been more serial rather than having many issues going on at once, until the last decade. Going from my lungs to my head to my GI tract over all at once saved my life and evaded diagnosis. And I am atypical CF meaning genetically, I am heterozygous S1235R, and certainly have enough CF issues to qualify. Depending on whose research you read this mutation can cause exactly my profile, or having no contribution to disease at all. If I couldn't ferret out who's data to believe, this would be exasperating. More to my point, very few people can explain the implications of the genetic test you just laid out, if anybody could.

Sweat chloride tests are still considered gold standards. Even so, people who have children undoubtedly with CF struggle with multiple tests for nothing more than the satisfaction of saying what you see in symptoms can be validated if you learn to sweat badly.

Assure yourself, maybe by talking with your doctor, that regardless of this ridiculous result, everything CF is being watched and/or treated. Any good CF doctor knows there is too much unknown in this test to say anything useful has been learned. I know it would be far better to have that confirmation. You may want to confirm CRMS, which you pretty much have from your description with the understanding that your child needs appropriate treatment along with a very close watch for emerging CF issues.



Great read littlelab4CF,
Since these genetic tests my specialist (not CF) has put him on enzymes as he was getting bad odemas (swelling to his feet). He was putting on sufficient weight but not getting the protein. Since being on creon for the past couple of months he has gained weight and his stomach pains have ceased. His diareah is much better and has absolutley no swelling to his feet. Since his adenoids were removed, his sinus drainage has gotten much worse. He does have nasonex but it doesn't seem to be helping much. He has not been seen by the CF clinic since his initial tests, but I will be pushing for this. They seem to only rely on sweat test and genetic test results.


Glu528Glu its not exactly a mutation rather than a variation(which reduces cftr by 10%), I have it without any other pathological mutation on my DNA.The genetics told me that it is not disease causing by itself or with a combination of an another mutation.I am 23,totally healthy but with borderline sweat test(caused by this variation according to them)


New member
CF diagnosis questioned...after 40 years

Very interesting thread.

I am currently looking into testing for PCD (primary ciliary dyskinesia) after being treated for CF for more than 40 years. My Pfts are currently in the 40s. I was diagnosed by sweat test at age 4, but now I test positive on sweat tests. I have one DF508 and one unknown mutation.

Last year, I also drove to Iowa for a nasal potential difference test (nasal PD test). "This measures how well salts (sodium and chloride) flow across the mucous membranes in the nose. This type of test can be helpful when the results of a sweat test or a genetic are not clear." Again, I tested negative. Every specialist I encounter is baffled! :)

Perhaps I really have CF (Atypical of course!) or something else. Hopefully, time will tell.


Active member

I know that it is difficult but you MUST get your children to a CF SPECIALIST. No matter how good your non CF specialist is, he/she is not trained to treat CF PATIENTS