Genetics Overview

What are candidate genes and how do they help scientists?

Candidate genes are genes that scientists think may contribute to a disorder either because of where they are located, because of what they do, or both. In situations where the scientists think they know the small region of the chromosome where a gene might be from other studies, they look at the genes in that region. This laboratory technique is like knocking on the door of every house on a block until you find the one your friend lives in. They do this by looking to see if differences in the candidate gene are present in people with the disorder more frequently than those without.

Sometimes scientists will not study genes by location, but by what the genes do (regardless of their location). For example, if a disorder affects the brain, they may look at genes known to make things used by the brain. Most often, in order for scientists to establish that a gene contributes to a disorder, other scientists must be able to find it in their research too. Thus, the next step is to see if other scientists can see the same finding. It is only then that scientists will agree that a gene contributes to a disease. The next step is to research how the gene works and why it causes the problems that it does.