 - At present, there is no research instrument that measures symptoms in children with chronic GVHD. Treatment practitioners may use one of several pediatric quality of life questionnaires, but because none of these is specific for chronic GVHD each instrument has potential gaps in its ability to assess the full spectrum of problems experienced by children with chronic GVHD. Researchers are interested in developing a better understanding of the disease burden experienced by children and adolescents with chronic GVHD. 