Heterzygous CBAVD mutation TG12-5T/TG10-9T

Question

Hello,
my daughter has the above mentioned mutation of an atypical CF, how did it happen?
Many greetings, S.

Answer

Dear Mrs. S.,
If I understand you right, you are correctly a bit confused by the name "CBAVD (congenital bilateral aplasia of the vas deferens) mutation" - finally CBAVD is not a topic for women.

"CBAVD mutation" is an unsuitable description for the CFTR variant TG12-T5: CFTR- TG12-T5 can be judged as a genetic variant with an impaired function of the CFTR (independently if it is found in a male or female).

With this there is the risk associated, to get a so-called atypical course of a "CFTR-related disorder". That means a "disorder caused by CFTR, however not CF". With that goes also, but not exclusively, the mentioned CBAVD; also pancreatitis and/or bronchiectasis belong to the "CFTR-related disorders".

There are many people who have one healthy CFTR gene (e.g. the TG10-T9 CFTR) and in addition a CFTR that is not fully functioning, like the TG12-T5 CFTR and who will never have to consult a physician due to a CFTR-dependent impairment (thus e.g. do not suffer from striking abdominal pain).

In summary: TG12-T5 CFTR is a genetic variant with and impaired CFTR function. If the other CFTR gene is however functioning, this becomes only evident to a human geneticist: genetic carrier for only ONE CFTR-genetic impairment are healthy, CF occurs, if TWO defective gene copies of the CFTR gene have been inherited.

Best regards,
Frauke Stanke

10.01.2015