Siblings - similar severity?

[Angelo]

If we get one mutation from each parent, and both parents are non-symptomatic carriers (that is they each carry only 1 mutation), then it would stand to reason that siblings who have CF (get both mutations) will have the identical mutation pair. Further reasoning, assuming identical environment, would conclude that the siblings have very similar experience and severity. I knew identical twins with CF, and they almost always had the same problems at the same times.

I am 53, but I had a brother about 1 year apart in age. He died at 3 months with very severe symptoms. He had a feeding tube from the beginning. I was diagnosed at the age of 6 months, but had a fairly healthy time through high school and college. No CPT and very rarely doing antibiotics or other meds. The more I think about it, the more curious I am as to why we had such different severities of CF.

I would appreciate other siblings sharing their experience, especially if you have different severity and experiences, and do you have any explanations for such.

 

[TreasureGoddess]

I don't have experience with this, just wanted to say I loved your "3 yrs past my expiration date" on your signature. I've heard siblings often have very different symptoms and severities of this disease.

 

[Angelo]

I don't have experience with this, just wanted to say I loved your "3 yrs past my expiration date" on your signature. I've heard siblings often have very different symptoms and severities of this disease.

Thanks, TreasureGoddess. As I am sure, many of us have had bouts with that "expiration date". And this is just the latest. God has rescued me from a deathbed more times that I can recount. I am in the process a writing a book. But unlike several books about the CF journey, this one will be fiction based on the truth. I chose that format for a variety of reasons, but the purpose of the book will be to shed light on the adult stem cell treatments that are available to reverse the damage of CF and bring about more awareness and funding to help pay for those expensive treatments. As for now, the treatments are not allowed in the U.S. Follow my blog if you want to keep up with it.

 

[Jet]

Angelo - I'm one year younger than you. I too lost my brother to CF. Our severity level and experiences were very different. He died to earlt to have any genetic testing. I'm only speculating but maybe it's the other genes you get from your parents. Maybe we got the same CF gene's but I got others that helped me compensate more for the CF.

 

[JustaCFmom]

I understand your curiosity.

While not too likely, maybe one of your parents actually had a (very) mild case of CF so the sibling got the more severe mutation, while you got a "mild" mutation?

The truth is they are researching this because there are such variations between siblings. They are trying to find those modifier genes.

I am sorry you lost a brother so young. Ir must have been so hard for your parents.(U)

 

[Norman Fitness]

I had a sister with CF who passed away in 2006, she was 18 but she always had much more severe symptoms then me. We both had the same mutation, double DF508. I was diagnosed at 8 months old but she was already 3 years old, so I always assumed that was why she was a lot worse because she had gone 3 years with out any treatment. Not sure if that is the case though. She was in the hospital all the time but I didn't have my first hospital stay until 7th grade. She had a double lung transplant in 2004. I did catch a lot of the same bugs as her but it didn't really affect me the same.

 

[4hats]

Angelo, so sorry about your brother. I can't even imagine what it was like for your family to deal with his death. I have a sister with cf that is a year and a half younger than me. Though we have the same mutations, our symptoms are different. My lungs are more problematic than hers. I culture 4 different bugs. She cultures none! I have hemoptysis from time to time. She has never had hemoptysis. I cough up green mucus everyday, throughout the day. Her mucus is generally clear, maybe a little yellow. I use a lot of antibiotics. She doesn't. We both love to exercise and run which has helped us both to maintain very good PFTs nonetheless. My sister has stomach issues and takes enzymes. My stomach is strong and I take no enzymes. We were both tested to be pancreatic sufficient. Siblings with CF can be so different.

 

[AttyMom]

I'm 44 and have a sister with CF who is just shy of 40. While neither of us has full-blown CF (we're both pancreatic sufficient) her symptoms have always been worse than mine and her pft's usually have been about 10-15% lower.

I asked my dr how this could be with us having the same mutations. He likened it to why my two sons look and act differently despite having the same parents and same genetic make-up. It all has to do with the modifier genes.

 

[welshwitch]

Yup I agree with the modifier genes. Those things have saved my life

 

[Angelo]

what is a modifier gene?

 

[randomgirl]

My older sister and I have the same mutation but way different outcomes. We are 4.5 years apart. Her lung function are in the 90's and she is borderline CFRD but she takes good care of herself so she doesn't need insulin most of the time. I was diagnosed with CFRD at age 14 and diagnosed with liver disease at age 15 I think. Then I received a double lung and liver transplant at age 24. I was/am very good about taking my meds though. I think it's stinky because she's afraid she will go down the path I went on. I hope that never happens.

 

[JustaCFmom]

modifier genes

what is a modifier gene?

Noun

1.

modifier gene - a gene that modifies the effect produced by another gene

http://www.thefreedictionary.com/modifier+gene

https://www.google.co.il/search?q=Modifier+Genes&oq=Modifier+Genes&aqs=chrome..69i57&

 

[Aboveallislove]

My understanding is that the cf dr do not yet know what these modifier genes are but that they are confident that there are some other genes that modify how the cftr affects cf organs because that is the only way to explain some of the huge variations in cf with those with the same cf genes and environment. I understood the dr think it is 50 genes and 50 environment that affects outcome...others hear anything on this?

 

[Angelo]

Noun

1.

modifier gene - a gene that modifies the effect produced by another gene

http://www.thefreedictionary.com/modifier+gene

https://www.google.co.il/search?q=Modifier+Genes&oq=Modifier+Genes&aqs=chrome..69i57&

thanks for the info. looks very complicated, but I get that a gene can alter the way another one is expressed and can account for the variations in the same mutations.

 

[Keepercjr]

I am another one here who had a sibling who fared much worse. My brother died at age 13 (I was 16). Here I am at 33 and doing pretty good! I am pancreatic sufficient and he wasn't. My new CF doctor has a theory about both of my mutations on the same gene but we really don't know.