>>96926807Only in the case that both share recessive genes which express as diseases or life threatening conditions, and particularly when both already express that bad trait. For a large amount of people though, there really isn't much to worry about as they don't carry or express a particular bad gene, and even for carriers of a bad recessive trait, they only have a higher likelihood rather than guarantee of showing that trait.
Now getting your mom or daughter pregnant on the other hand, is an entirely different can of worms, and can be particularly devastating depending on the gender of the kid (e.g. mom and son having a daughter)
