Chapter 10

Molecular Diagnosis

Keypoints

• Identification of the gene for a disorder permits diagnostic testing by direct mutation analysis.

• Some genetic disorders are associated with a wide range of allelic heterogeneity.

• Genetic testing may reveal variants of unknown significance that require special care in interpretation.

• Molecular genetic tests are often first developed in research laboratories, but clinical testing requires transfer of the test to a certified clinical laboratory.

Keypoints

• Genetic linkage analysis can be used to track a genetic trait through a family if the responsible gene is not known or mutations cannot be easily identified.

• Genetic tests can be evaluated in terms of analytic validity, clinical validity, and clinical utility.

• Genetic tests raise a number of potential ethical issues that should be considered in deciding to initiate testing.