Probably one of your parents passed the faulty allele to you. There is the rare chance that the mutation occurred sometime when the allele was passing to you to your child (in fact, I’m really not sure when/what causes the alleles to mutate) but it is much more likely that you inherited it from one of your parents.

   You’re also probably right is speculating that the allele has gone from generation from generation in only the ’carrier’ state. My daughter is the only child that we know of on both sides of the family with CAH. In addition, there has been no early infant death for unknown reasons or a history of LOCAH like some families do. It’s funny how these things pop up at times. My family jokes around a lot about who could be a carrier of the faulty allele (got a craving for salt, you’re a carrier- that kind of silly stuff) However, it turns out that my husband and I have the exact same mutated allele and we apparently both had great grandmothers from the same little village in Italy, so we like to blame the Italian side of our family for our little mutation. I find it more disturbing that we probably have a common relative 3 or 4 generations back, but we have no idea who!

Crazy genetics- who ever knew it would come in so handy!