The purpose of this study was to identify those critical factors that genetic nurse experts perceived could influence parental decision-making to seek or to reject presymptomatic testing of their children at risk for treatable adult-onset genetic disorders (neurofibromatosis 2, familial adenomatous polyposis, and von Hippel Lindeau disorder). Perceptions of ISONG genetic nurse specialists were surveyed through a modified Delphi technique and four major themes emerged: personal experience with severity of genetic disorder, receiving accurate information from credible sources, availability of quality treatment, and risk perception. Currently, there is a paucity of extant research that identifies critical factors influencing parental decision-making about this relatively new testing alternative for children. Thus, these experts are an important source of valuable information needed to identify such factors. Findings may be useful to design a qualitative study with parents to investigate this issue.