A combination of linkage mapping and a candidate gene approach has been the most successful method of identifying disease genes to date. The candidate gene approach is useful for quickly determining the association of a genetic variant with a disorder and for identifying genes of modest effect. This approach has certain advantages over traditional linkage mapping or positional cloning approaches. The current methods for evaluating risk associated with candidate genes complement traditional linkage efforts in identifying susceptibility genes for alcoholism. As more SNPs are identified throughout the genome, some of those SNPs also will be located within candidate genes, thereby allowing researchers the use of the candidate gene approach on a genome-wide scale.
