CF and diagnostics

Question

With people carrying both a mutating and a normal CFTR gene (i.e., genetic carriers), is it possible to diagnose whether they are carriers even if they do not have CF?

Please reply.

Answer

Hello,

in order to tell whether a healthy person is a “genetic carrier” (a so-called heterozygous carrier) of CF, a molecular genetic test can be performed. If a family member suffers from CF, the test should be carried out with the patient first. If both of the CF patient’s inherited mutations (from mother and father) are known, a targeted search for the mutation can be carried out with her/his relatives in order to confirm or rule out the “genetic carriership.” Sometimes, it is also possible to confirm or rule out the carriership if the mutations of the affected patient are not known. The validity of the molecular genetic diagnostics depends on the respective family situation.

Occasionally, with CF, molecular genetic testing for heterozygosis is also indicated if relatives of the test person do not show any signs of the disease. In any case, before taking the test, one should get a genetic consultation. In such a consultation, the expected validity of a test for genetic carriership will be explained in detail to those who are seeking advice.

Kind regards,

Dr. M. Stuhrmann-Spangenberg

12.01.2009