The Spillover of Genomic Testing Results in Families: Same Variant, Different Logics

Stefan Timmermans, Tanya Stivers

Due to heritability, next-generation genetic tests have the potential to affect family members beyond the patient being tested. Geneticists and genetic counselors, in dialogue with patients and their relatives, will need to establish for whom and in what way genomic testing results matter during the communication of testing results, indicating the spillover of presumed pathological variants. On the basis of video-recorded consultations of the return of exome results in a genetics clinic, we distinguish three different logics deployed to explain the relevance of the findings for the patient, extended family members, and unborn relatives. While geneticists tend to be cautious in interpreting findings for the patient and living relatives, the findings become more deterministic in the context of reproductive decision making. The presentation of results then establishes the causal role of variants and reflects back on disability as a state to be prevented, in the process establishing genetic ties between kin.