This chapter takes a discourse analytic approach to examine communication of genetic knowledge in an online forum in Mainland China. The data corpus consists of 270-plus forum interactions among clients who have used direct-to-consumer (DTC) genetic testing, staff members of a genetic testing company, and individuals who are interested in but may not yet have used genetic tests. Our analysis reveals that the forum interactions demonstrate complex hybridity and blending of various discourses and communicative practices. Specifically, the online mode of communication enables the participants to engage in direct health advice-seeking and open discussion of sensitive genetic health topics. The forum also allows the participants to contest the ‘authoritative’ versions of genetic knowledge advanced by the genetic test company. Through these discursive practices, the participants actively engage in constructing and negotiating the meanings of an emerging genetic technology. Such increased public engagement with genetic science reveals a blurring epistemological distinction between experts and lay people in the modern society where access to genetic information has been democratized through various digital platforms.