Biobanks and biobank harmonisation

Over the past decade and a half, genetic epidemiology has experienced an important shift from family-based studies of genetic linkage to individual-based studies of genetic association (Chapters One-Four). In part, this follows the recognition that if the 'common disease, common variant hypothesis'^1-5 is true for at least a proportion of important genetic determinants of complex disease, these determinants - which will predominantly exhibit weak aetiological effects⁶ - will be identified more easily using association studies of population-based samples⁷. The shift to using association studies has been accompanied by an increasing methodological focus on optimal approaches to the design, analysis, meta-analysis and reporting of genetic association studies^{8-15; 65-67} (www.cdc.gov/genomics/ hugenet/strega.htm). This chapter describes these changes, and the growing international focus on biobanks with which they are associated.