Cystic Fibrosis

[Guest]

I just had a brief question. Genetics and cystic fibrosis seem quite complex. My brother is a carrier of cystic fibrosis and just found this out at the age of 27 years old while in the process of him and his wife trying to get pregnant. I was curious as to how the genetic process works with hime being a carrier. His wife is being tested as we speak and if her test comes back negative for being a carrier, what are their chances of their children having the cystic fibrosis gene to become a carrier? Is there any possibility that their future children will have CF? Just a few questions that I am curious about. I am a nursing student with only one semester left until I become a registered nurse and when something medical comes into your family, why you become curious. A response would be greatly appreciated. Thanks..CE

[Guest]

I caught your question while waiting for a reply from the doctor. I can tell you with an extremely high degree of certainty I can answer your question. (Dr. Please correct me if you disagree)

on average 1 in 31 caucasians carry a Cystic Fibrosis mutation recessively. To have a CF child two carriers must produce the child and a 25% chance exist the child will have CF.

The genetic test screens for about 85-100 common CF mutations. There are an additional 200-300 mutations that do not get identified in a typical genetic screen as they are very, very rare.

If the wife test as a non carrier the chances of having a CF baby is nearly non existent. It would require the wife to have an rare unidentified mutation (which is very rare) and then a 25% chance if she does have a rare unscreened mutation.

Testing her is a great decision. If she has no CF mutations the chance of a CF baby is completely non existent. It requires both parents to be CF carriers. The children will have 50% of being carriers even if she is not due to the husband. This should be monitored in the next generation as well.


[quote] I just had a brief question. Genetics and cystic fibrosis seem quite complex... [/quote]

[Guest]

good answer! you are correct.
[quote] I caught your question while waiting for a reply from the doctor. I can tell you with an extremely high degree of certainty I can answer your question... [/quote]