PRESENCE OF THE 918-MUTATION IN THE RET PROTOONCOGENE IN A MEXICAN PATIENT WITH MULTIPLE ENDOCRINE NEOPLASIA TYPE-2B

The dominantly inherited Multiple Endocrine :Neoplasia cancer syndrome type 2B (MEN2B) is characterized by the presence of medullary thyroid carcinoma (MTC), phaechromocytoma (PHAEO), mucosal neuromas, ganglion euromas of the intestinal tract, skeletal and ophthalmic abnormalities . MEN2B has been associated with a specific point mutation in the tyro sine kinase domain of the RET proto-oncogene (918RET mutation). We inv estigated a Mexican patient MEN2B for the presence of the 918RET mutat ion using the polymerase chain reaction followed by restriction endonu clease digestion. We have detected this mutation in DNA from the patie nt's MTC, PHAEO, and peripheral blood cells, bur not in DNA from the p atient's mother, suggesting that this mutation arose de novo. Our resu lts are in agreement with the suggestion that the 918 RET mutation is present in a vast majority of MEN2B cases around the world.