Sharing of genomic and associated data is becoming an essential component of clinical practice and biomedical research. The advantages for accelerating the diagnostic, preventive and therapeutic benefits are widely acknowledged, and genomic data sharing is increasingly encouraged by journals and funding bodies. Genomic data sharing raises a range of legal and ethical issues, but grappling with them presents a significant challenge given the extreme diversity in data sharing practices: from defined sharing of individual data for clinical purposes, to broad-scale public sharing of research data, to uploading of data from direct-to-consumer tests by community members. Most commentary to date has discussed data sharing issues in broad terms, but the debate can only progress if we identify and engage with more granular details grounded in jurisdictional and contextual specifics. Yet the sheer scale of the genomic data sharing universe can overwhelm this attention to detail, leaving a gap between the anecdotal and the universal. To overcome this gap, we developed an empirical approach to producing a set of representative scenarios that capture the diversity of current and anticipated genomic data sharing practices and allows legal and ethical analysis of the key issues at a granular level. The specificity of this approach provides a strong foundation for developing useful and relevant regulatory recommendations, and is potentially of benefit in other areas with similarly complex landscapes.