Laboratory diagnosis of genetic disorders.

Many genetic disorders affect vision or result in ophthalmic findings. Laboratory testing plays an important role in the diagnosis of genetic disorders and in carrier testing. Recent advances in cytogenetics, biochemical genetics, and molecular genetics have increased the understanding of many diseases and have allowed some to be defined at the molecular level. Concomitantly, new laboratory tests have been developed for several important hereditary eye diseases, including some forms of retinitis pigmentosa. These developments not only herald marked advances in the understanding of disease, they also introduce new legal and ethical issues that will affect the primary care clinician when using laboratory testing for genetic disease.