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Molecular Basis of Heredity: Part 4. Gene Identification and Tests

Author(s): Raye L. Alford, PhD

Candidate Gene Approaches to Gene Discovery

Another approach to discovering genes associated with disease is candidate gene approach, which is based on assumptions about or knowledge of the biochemistry of a disorder. For example, if the primary symptom of a particular disorder is activation of inflammatory pathways in a particular tissue, genes that encode proteins involved in inflammatory processes might be reasonable candidates to investigate for disease-associated genes. In this case, one might limit the selection of polymorphic markers to be analyzed to those that lie within genes involved in inflammation, as opposed to selecting a group of markers distributed throughout the genome. This approach has been used successfully to discover a number of disease genes. Its advantage is that case-control groups can be studied, eliminating the need to collect data from large, multigenerational families. Its disadvantage is that one must make certain assumptions about the pathophysiology of the disorder. If those assumptions are incorrect, or if the case and control groups are not carefully selected, gene discovery may not be successful.