Genetic association

Genetic association is when one or more genotypes within a population co-occur with a phenotypic trait, more often than it would be expected by chance occurrence.

Studies of genetic association aim to test whether single-locus alleles or genotype frequencies (or more generally, multilocus haplotype frequencies) differ between two groups of individuals (usually diseased subjects and healthy controls). Genetic association studies are based on the principle that genotypes can be compared "directly", i.e. with the sequences of the actual genomes.