Narrating uncertainty: Variants of uncertain significance (VUS) in clinical exome sequencing

摘要

Exome sequencing is an innovative next-generation sequencing technology that examines the majority of disease-causing genes with a single test. Physicians and patients resort to exome sequencing to probe for a genetic cause of disease. The technology produces about 20,000 variants and many are of uncertain clinical relevance. Drawing from ethnographic field notes and audio recordings of over 1,500 patient cases discussed at genetic data board meetings over a three-year period, this article reports on how a collective of laboratory scientists and clinicians contend practically and conceptually with variants of uncertain significance (VUS). Rather than standardizing the inclusion criteria for a VUS, the collective contextualizes each VUS with its own evidentiary narrative. The VUS then becomes subject to revision based on evolving evidence, further testing, and updated interpretations. We argue that the epistemic uncertainty of VUS becomes productive; it indicates future causality and suggests that genetic causes can explain patients' symptoms even if no known pathogenic variants could be located.