Why research the genetic status of members of a family affected by a hereditary disease and reveal this information to them, particularly when there is no treatment available? On what basis does the individual at risk make the decision of whether or not to find out their genetic status and whether or not to inform their relatives? What are the effects of the presymptomatic diagnosis on those who chose to undergo it? How and to what extent does it change their lives, if at all? These three questions are the starting point for the present overview of the literature on the social and ethical issues of presymptomatic diagnosis. The analysis is based on a corpus of 57 articles and 7 reports gathered from Scopus, Cairn and the websites of various institutions, and identifies two main approaches. The first approach is to consider the decision as a rational process in which the associated risks and benefits are weighed. In a certain way, these risks and benefits have an objective existence, even if they must be assessed subjectively by each individual. In this context, the practitioner is, a priori, as well placed as the individual themself to determine the "right decision", either with them, or possibly in their place. A second approach is to consider that the decision is only one point in a long process which gradually leads people to both incorporate and come to terms with what the illness means in their lives, and how the presymptomatic diagnosis can influence the course of their lives. In this approach, a shared journey is forged between caregivers and the individual, the aim being to explore together the significance the diagnosis can have for them. The issue of clinical trials as a potential motivation for receiving a presymptomatic diagnosis complicates the analysis by revealing long-term collective benefits, in contrast with immediate individual risks. Should this element be considered, and if so how, should this be within the options presented to the individual with a view to a possible presymptomatic diagnosis? The protocols discussed in this review provide useful benchmarks for ethical framing both by and in practice: the relatively long time frame of the procedure, the process of collective exploration of what the decision may imply, and the non-interference of researchers are arguably the main features to retain.