I think there are a few donors here in the States who have been both liver and kidney donors, I don't think that is too common so you will have to research what the likelihood is if you were to become a liver donor, what the chances are a hospital would consider you for a kidney donor subsequent to that surgery, if that is a concern for you. In addition, liver surgery is a much riskier surgery, so deciding to have elective surgery of this nature with a child so young may also be something to think about. One never knows what the future brings. You may or may not even be a match to your son or you may not even be healthy enough to donate. As a parent, I also wanted to hold onto my kidney for the just in case if one of my children needed it. Hopefully, your son will just be one of the many who are born with one kidney and whose bodies compensate. Sounds like you really want to help children in some way. Perhaps you can explore other areas besides living donation that may also satisfy this need. Are you a blood donor or part of a bone marrow registry?