[Gene mutation and genetic counseling].

With the advance of technology of genetic research, a lot of genetic testing has been available as a clinical service. The genetic testing has sometimes been applied to not only diagnosis of a patient, but also pre-symptomatic diagnosis, prenatal diagnosis, carrier diagnosis, and susceptibility diagnosis. Genetic knowledge and psychological support are necessary for the subject for adequate voluntary decision making. Thus genetic counseling by a clinical geneticist or a genetic counselor is very important and must be offered on every genetic testing according to the Guidelines for genetic testing proposed by Genetic-Medicine-Related Societies.