Dear Karen, I was so deeply shocked and saddened to hear the dreadful news of Marks passing. He was an inspiration to many people in the CHI community. His ability to be able to explain extremely complicated science to the families that CHI affects was a joy to behold. He felt so deeply about this awful disease and the family’s, it really shone out in his work. Personally I found Mark supportive in my part of the CHI world, and this enabled me to better support the families I dealt with every day. Should there be a memorial of any type I would like to attend. My heart goes out to Karen and the girls.