This study is the first to explore the psychosocial experience of members of Portuguese families with late-onset variant transthyretin amyloidosis with polyneuropathy (A-ATTRv-PN). Based on a constructivist worldview, this phenomenological investigation followed a qualitative approach by conducting eight interviews and analyzing qualitative data. The main results suggest that the psychosocial experience of the members of families interviewed is marked by: (a) a delayed awareness of the family disease (viz., in adulthood), (b) psychosocial impacts (viz., emotional and other impacts related to work, parenting, caregiving) experienced and anticipated in an adult phase of the life cycle, and (c) the use of approach strategies (e.g., seeking information about A-ATTRv-PN and seeking social support) and/or avoidance strategies (e.g., avoiding seeking information and talking to others about the condition) with a view to accommodating A-ATTRv-PN in personal and family life. These results differ from the life trajectories of members of Portuguese families with A-ATTRv-PN described previously and extend previous scientific evidence on the psychosocial experience of members of families where the disease typically appears late, contributing to further study on this topic and to the optimization of genetic counseling practices and health policies that respond to the psychosocial needs of members of Portuguese families with late onset of the condition. Future studies should continue to deepen our understanding of the psychosocial experience of this population to improve the clinical response provided to patients, families, and caregivers.