Hi Natalie,

My name is Robin and I am a high school science teacher.  One of the areas I have to teach is genetics, so I will try to explain the answer to your question in everyday language instead of all the medical terminology that tends to confuse everyone but doctors :).  Anytime you hear a doctor talk about a mutated gene they are referring to one of the exon’s on the gene.  The exon is just a small sequence of DNA that has changed because of being coded incorrectly during development.  The exon instructs our bodies on what proteins and amino acids to make.   If the proteins and amino acids aren’t being processed correctly because of the mutation of the exon, then conditions like CAH and other hormone based conditions can happen.   As far as your daughter is concerned, it is extremely possible that she has two mutations on the same gene or she could have the mutations on multiple genes.  I hope this helped a little bit.  This is one of those topics that we spend weeks on in my class, so it is difficult to explain in a short post.

Robin