Polymorphisms

Question

I am in the 26th week of gestation. My husband was checked for 95% of the CF mutations and only a polymorphism was detected. Is it necessary for me to get checked, or does the polymorphism does not cause any issues, whether or not I am a carrier? Thank you.

Answer

Dear friend,
You are at the 26th week of gestation and your husband has been checked for 95% of the CF mutations with only one polymorphism detected.
The term "polymorphism" is defined a a change in the genetic material that occurs in more than 1% of the general population. Previously polymorphisms were thought to have no clinical consequences, however, several polymorphisms in the CFTR gene are known to influence disease severity in subjects with CF and CFTR-related disorders. Therefore one has to know the exact polymorphism in order to predict its influence--this is some information you can get from a genetic counselling or the genetic result in detail. If we assume, that the found polymorphism of your husband does not cause CF if it comes together with a CF-causing mutation and is therefore a so-called "neutral polymorphism" , the following pertains:
The absolute prevention of CF is not possible, but the possibility of having a child with CF can be greatly reduced, depending on the percentage of CF mutations being checked – the greater the percentage the lesser the chance-, something that has been done in your case.
In case you have been checked for CF mutations as well, the possibility of CF is almost non existent.
In case you are a carrier of a CF mutation the possibility of your child having CF is not zero, but it is very small.
Practically, I believe that you have limited this possibility to a very great extent.
In case of a future pregnancy you could get checked as well for an even greater number of CF mutations (for prevention reasons).
Yours friendly,
Dr. Stavros Doudounakis

23.09.2013