Genetic Analyses of a Family with Familial Medullary and Papillary Thyroid Carcinoma
Kogon MD., Myers SM., Mulligan LM., Green JS., Kwan A., Morris-Larkin C., Kaiser S.
Medullary thyroid carcinoma (MTC) and papillary thyroid carcinoma (PTC) are both associated with mutations of the RET protooncogene. In MTC, these are activating point mutations which may occur somatically, in sporadic tumours, or in the germline, in the case of multiple endocrine neoplasia type 2 (MEN 2). In PTC, somatic rearrangements of RET result in the expression of a chimeric oncoprotein with transforming potential. In this study, we investigated a family including two members with bilateral-multifocal MTC, suggesting a diagnosis of MEN 2, co-occurring with multiple cases of PTC. We showed that a point mutation of RET codon 618 is present in the two family members with MTC but is absent in those with PTC. No rearrangements of RET were detected in any family members. We conclude that the MTC and PTC observed in this family do not arise from the same RET mutation. © 1999, by Walter de Gruyter GmbH & Co. All rights reserved.