Today’s DNA sequencing technologies now make it possible to sequence whole human genomes cost effectively and with speed. Sequencing initiatives are generating vast volumes of data that – theoretically – give scientists a starting point to drill down into individual patient genomes in the hunt for disease-related variants, and also to mine collectives of huge public datasets to aid our understanding of the genetic basis of disease, unpick disease mechanisms, identify drug and diagnostic targets, and stratify patients for clinical trials and personalised medicine.