Spontaneous mutations

Question

Hello,

As I said before, our daughter has been diagnosed with atypical cystic fibrosis (CF). Following this diagnosis, we did a gene test and it turned out that only one of us is a gene carrier.

My questions: how frequently do spontaneous mutations occur?

The human genetics laboratory would now like to test my daughter’s blood as well.

Many thanks.

Kind regards
C.M.

Answer

Hello,

spontaneous mutations are rare, but they do occur. In case of suspicion of a spontaneous mutation, i.e. of a mutation in the child that cannot be shown in either parent, it is advisable in to repeat the examination of the child and the parents in any case in order to rule out a mistake on the part of the laboratory (e.g. a mix-up of the samples). If the first result proves correct, this could mean a spontaneous mutation (neo-mutation) has happened. Formally, a spontaneous mutation would be proven if a test of the parents’ and child’s so-called genetic fingerprint would show that the indicated parents really are the child’s biological parents. Such a targeted filiation test can only be done after the parents have been sufficiently informed and given their written consent, and it is mostly not relevant for the question of a potential repetition of the disease in a couple’s other (future) children. In keeping with the German Genetic Diagnostics Law, the molecular genetic result of your daughter and the indication for your own test would have been explained to you in the context of a genetic consultation. If this has not happened, you should absolutely have your own test results explained in the context of a genetic consultation.

Kind regards
Prof. M. Stuhrmann-Spangenberg

07.09.2010