The Genetic Information Nondiscrimination Act of 2008 (GINA) was passed to encourage patients to seek genetic testing that could improve health outcomes and provide opportunities for preventive measures. GINA protects individuals from discrimination based upon genetic information, but not upon manifested diseases and conditions. Because the manifestation of a disease establishes a threshold of protection for individuals under GINA, the definition of manifestation is crucial to understanding the scope of the bill. This paper examines the range of possible legal definitions of disease manifestation and explores the historical struggle that courts have faced when trying to apply these different definitions. Specifically, the paper examines three frameworks that courts have used in the past to interpret the manifestation of a disease; “manifestation as apparent symptoms,”“manifestation as patient action,” and “manifestation as physician action.” We argue that the “manifestation as physician action” is the best framework to utilize in this law generally, but that the definition of manifestation should be read in the light most favorable to a plaintiff in order to achieve the underlying goals of GINA.