Candidate gene

A candidate gene (Latin candidatus = candidate; Greek geneá = ancestry) is a gene which, based on previous studies, observations or hypotheses, is thought to play a role in a particular disease or phenotype.

In genetic research, a candidate gene approach is often used to identify genes that may be involved in the development or inheritance of certain diseases or certain traits in plants. A candidate gene approach requires a prior hypothesis that certain genes of interest contain variants that may be associated with a trait or disease. Candidate genes are usually selected when there is good evidence that

• the proposed candidate gene is biologically relevant to the trait of interest
• the variants of the candidate gene influence the overall function of the gene and
• the polymorphisms of the selected candidate gene occur frequently enough in the population to allow a meaningful statistical analysis.

These genes are then examined in a larger population of organisms of a species to confirm or refute their role.

Candidate genes can be identified in different ways, e.g. by genomic studies of closely related individuals with a defined trait, by genome-wide association studies or by studies in animal or plant models. Once a candidate gene has been successfully identified and its role in the expression of a trait has been confirmed, this can lead to a better understanding of the underlying mechanisms and potentially to new treatments for diseases.