The rapid emergence of large-scale genetic databases raises issues at the nexus of medical law and ethics, as well as the need, at both national and international levels, for an appropriate and effective framework for their governance. This is even more so for retrospective access to data for secondary uses, wherein the original consent did not foresee such use. The first part of this paper provides a brief historical overview of the ethical and legal frameworks governing consent issues in biobanking generally, before turning to the secondary use of retrospective data in epidemiological biobanks. Such use raises particularly complex issues when (1) the original consent provided is restricted; (2) the minor research subject reaches legal age; (3) the research subject dies; or (4) samples and data were obtained during medical care. Our analysis demonstrates the inconclusive, and even contradictory, nature of guidelines and confirms the current lack of compatible regulations. The second part of this paper uses the European Network for Genetic and Genomic Epidemiology (ENGAGE Consortium) as a case study to illustrate the challenges of research using previously collected data sets in Europe. Our study of 52 ENGAGE consent forms and information documents shows that a broad range of mechanisms were developed to enable secondary use of the data that are part of the ENGAGE Consortium.