So which strategy is best? Candidate gene or GWAS? This question is frequently posed by developmental scientists aiming to add genetic components to their studies (or submitting grants to do so for NIH review!). There is no easy answer. Most developmental scientists are not trying to discover new genes, as is generally the goal of GWAS. Thus, a more targeted candidate gene approach that aims to characterize risk processes and/or trajectories associated with identified genes is reasonable. However, we strongly recommend that this targeted approach is not restricted to the “usual suspects,” but rather, draws from the broader literature of genetic findings for the phenotype of relevance, and ideally, includes collaborators from large-scale gene identification projects in relevant fields, in order to take advantage of new findings emerging in the area. Further, with all the knowledge we now possess about LD structure, researchers should use this information to genotype markers that capture genetic variation across the gene of interest, not limit their study to a single marker or polymorphism (except in strongly justified situations, such as where previous studies that
