[An application of genetic diagnosis in MEN2a].

Multiple endocrine neoplasia (MEN)2a is known to be genetically linked to a locus on chromosome 10. The application of polymorphic DNA probes (RFLP) for the region made presymptomatic diagnosis possible. The validity and significance of genetic diagnosis has been proved in Caucasian MEN2a families in terms of early diagnosis and cure. In addition, non-carriers of the gene can be discriminated with a high degree of certainty and can be relieved from years of conventional screening program. An example of genetic diagnosis in a Japanese MEN2a family is shown. DNA analysis was done employing MEN203 as a probe. The usefulness of genetic diagnosis was confirmed in Japanese as well as Caucasians. Clinical consideration in carrying DNA analysis and the future of genetic diagnosis is also discussed.