Clinical molecular genetic testing

Recent advances in human molecular genetics are rapidly producing clinical genetic tests for a variety of conditions. In addition to tests for rare genetic disorders, tests for common illnesses with mixed genetic and environmental etiologies are being developed. While practice guidelines for test utilization are being developed, many physicians would benefit from additional knowledge about the design and limitations of these tests. This article reviews the genetic background necessary to understand linkage-based and direct mutations tests and discusses some of the issues physicians must consider when selecting an appropriate test for a given clinical situation.