Hi Lynn, we recently had attempted to have our son's gene mapped to find the cah mutations, but unfortunately they can not find either mutation. The lab told me that in 95% of cases they can find at least one and it is quite rare to not find either. They left it at that so I have been trying to find somewhere that offers more extensive testing. I have been speaking to Cornell and got a list of the mutations that they check for so I am going to check with the lab that tested my son and see if they checked the same things or not. You mentioned that you will be doing more extensive testing, I am very interested in the details (where/cost etc.) Please post back or email me at nanddgregory@netscape.net. Thanks.