For example, many alleles have been shown, through association studies, to cause some form of cancer, often with low penetrance.
Neither have genome-wide association studies brought a consistent focus - each has identified new loci.
Also inconsistencies in association studies with depression have been noted.
More than 50 genes have been examined in association studies with hypertension, and the number is constantly growing.
A suggested alternative to linkage studies was the genetic association study.
Population substructure also can be used to advantage in genetic association studies.
Estimating coverage and power for genetic association studies using near-complete variation data.
However, linkage analysis and genome-wide association studies have found few reproducible risk factors.
In 2006 over 100 genes were associated with asthma in one genetic association study alone; more continue to be found.
Also, an association study in a large sample 159 trios of European descent showed some evidence for this locus.