genetical testing

Question

My son 20 years ago underwent genetical testing in Poznań. It turned out, that he has F508 del mutation. On this occasion his mother, father and sister were also tested. Does it make any sense to perform another genetical testing in my son? Will the results of the tests influence the possible ways of treatment?

Answer

Dear Questioner,
it is not easy to give a straight answer to your question, as some points do not come out very clearly. First of all, we assume that your son is suffering from CF.

Then you mention, that F508 del mutation has been found: so in case your son is suffering from CF, did they find F508 del mutation on both genes? In that case, one does not need to examine your son again towards another mutation because we know the two mutations on both genes.

In case, however, that your son had been tested and F508 del mutation has been found only on one gene, and he is obviously suffering from CF, one could assume, that probably with the test 20 years ago, the other mutation on the other gene has not been found and then it would make sense to do another genetic testing in order to find the second CF mutation (use a test with a wider mutations panel) also with the aim to test the family about a carrier state.

Secondly, you wanted to know, if there are any therapeutic consequences beause of the genetic testing.
First of all, the basic therapy of the CF aiming at the symptoms is independent on the mutation and is based mainly on the clinical findings. However, for some specific mutations, drugs are currently in the clinical testing phase that correct the effect of a certain mutation. So in the future, there will be some kind of specific therapeutic consequences on the knowledge of the mutation, covering only some specific mutations, however. This is also the case for F508del mutation, where specific pharmacologic approches are currently tested. Of course, today it is not known whether these specific treatment trials will be successful enough to enter daily practise.

Possible decision of performing genetical testing again should be taken by prof. Michał Witt, who was most probably the one that performed the first tests in your son.
Contact with prof. Michał Witt: Dept. of Human Genetics, Polish Science Acacdemy, 32 Strzeszyńska str., 60-479 Poznań, phone: +48 61 823 31 87.
Best regards, Natalia KobelskaDbiel, MD, PhD

02.02.2009