ABSTRACT
Many researchers are presented with the opportunity to design a study to test genetic variants in a candidate gene for association with disease. As described elsewhere in this book, candidate genes might come from family-based linkage studies or from expert knowledge of physiological pathways. Study design includes selecting an informative set of markers to measure and this can be most effectively performed by first identifying all known genetic variants in the gene or genomic region. Single nucleotide polymorphisms (SNPs) are generally used as genetic markers for association studies because they are abundant and relatively easy to measure using high throughput methods.8 A PubMed search may locate some SNPs which have already been reported in the literature. However, only a small fraction of all known SNPs are likely to have been formally published in the peer reviewed literature covered by PubMed.
