A 71-minute lecture on how genomics is transforming medicine from trial-and-error to targeted, predictive care. Covers the paradigm shift from population averages to personalised treatment, variant interpretation using ACMG guidelines, the distinction between Mendelian and complex diseases, genome-wide association studies, and next-generation sequencing. Examines the critical equity gap: 86% of genomic research participants are of European ancestry yet Europeans represent only 16% of the global population. Introduces the HEIM framework for quantifying genomic data representativeness. Includes pharmacogenomics, liquid biopsy, direct-to-consumer testing, and ethics of genomic data. Delivered at the University of Westminster, 30 January 2026.