In this article I explore the meanings acquired by the notion of 'genetic inheritance' for families in Rio de Janeiro affected by a rare hereditary disorder, Machado-Joseph disease. My analysis examines three points: 1) how experience of the disease was thematized in the family prior to knowledge of its genetic and hereditary origin; 2) how knowledge of genetics affected the family's perception of their health and reproduction through the notion of risk contained in medical explanations; 3) finally, I problematize the meanings of 'hope,' a sentiment frequently cited by people with the disease and their descendants. Notably, despite the high value attributed to science and 'medical progress,' the use of certain biotechnologies is not always seen as positive or capable of enabling choices and actions in response to a rare disease. Notions of risk, responsibility and hope thus acquire singular contours for managing life and the continuity of the family.
Rare Genetic Disease; Machado-Joseph Disease; Genetic Inheritance; Family and Kinship; Hope