This study examined the impact of severity and preventability of a genetic disorder on belief that genetic test results should be shared with family members, desire to be tested, and opinions about physician's role in sharing information. Participants were 359 undergraduate students who received one of four descriptions of a fictitious genetic disorder called hemocythemia (i.e., factorial combination of high versus low disease preventability and high versus low disease severity). Logistic regression analyses indicated that disease severity and preventability did not influence agreement that genetic information should be shared with family members, interest in being tested for the disorder, or agreement that physicians should share genetic information without permission. Those who read about the disorder as preventable were more likely to agree that their family members should be tested for the disorder (odds ratio [OR] = 1.82, p < 0.05). Females, African Americans, and those of other races were more likely to agree that they would want their family members tested for liemocythemia than males or European Americans (p < 0.05). Describing the disorder as preventable minimized the effect of the severity manipulation on perception of disease severity (p < 0.05). Understanding a disorder to be preventable may increase encouragement of family members to be tested and affect perceived seriousness of the condition.