Choosing not to know: accounts of non-engagement with pre-symptomatic testing for Machado-Joseph disease.

This paper reports accounts from people at-risk for, or affected by, Machado-Joseph disease, and their family members, about their decisions not to seek pre-symptomatic testing, therefore remaining (for the time) uninformed about their genetic status. We draw on individual and family semi-structured interviews with participants recruited through a national patient's association (n = 25). Qualitative thematic analysis revealed three main categories of accounts: (1) justifying the decision "not to know", because either no clinical benefit was expected or predictive knowledge was anticipated as psychologically burdensome; (2) prioritizing everyday life, maintaining hope and the goal of living a valid life; and (3) the wish to know: ambivalence and conflict within the family. Findings suggest the value of genetic information is often questioned when no effective treatment or cure is available; and that people have different tolerance thresholds for predictive information, and this impacts individuals within the family differently. We discuss this in the context of the making of "responsible" decisions, and of the tensions that may arise within families between the best interests or wishes of a person and those of other family members. We hope this will clarify the reasoning of those who opt for non-engagement with medical genetic services and, more specifically, pre-symptomatic testing. Further, we hope it will be relevant for the provision of genetic counselling and psychosocial support to such families.