The RET protooncogene in sporadic pheochromocytomas: Frequent multiple endocrine neoplasias type 2 - like mutations and new molecular defects
- Universitat Rene Descartes, Paris (France); and others
To assess the pathophysiological role of the RET protooncogene in sporadic pheochromocytomas, we examined the two regions of the gene in which molecular defects are specifically associated with the Multiple Endocrine Neoplasias (MEN) type 2A (exons 8-11) and type 2B (exon 16). The sequences of both regions were amplified by RT-PCR or PCR from tumor RNA and/or constitutive DNA. The amplified products were analyzed by denaturing gradient gel electrophoresis using chemical clamps. In 28 patients with unilateral sporadic tumors six RET mutations were found: three in the MEN2A region, and three in the MEN2B region. Five patients had missense mutations: two in the MEN2A region (C634W and D631Y), and three in the MEN2B region (M918T). Analysis of leukocyte DNA in three of these patients confirmed that RET mutations were only present in tumor DNA. The sixth patient had lost exon 10 in the tumor cDNA due to the deletion of the dinucleotide AG at the 3{prime} splice acceptor site of intron 9; this molecular defect was only found in the tumor DNA. Thus RET mutations of the MEN 2A and MEN 2B regions are also found in ca. 20% of sporadic pheochromocytomas. We describe new types of molecular defects of the RET protooncogene in the MEN2A region which involve non-cysteine residues and the loss of exon 10. Further studies should be extended to analyze the entire RET gene. These findings have a profound clinical impact for the management of patients with supposedly sporadic pheochromocytomas.
- OSTI ID:
- 133471
- Report Number(s):
- CONF-941009-; ISSN 0002-9297; TRN: 95:005313-0199
- Journal Information:
- American Journal of Human Genetics, Vol. 55, Issue Suppl.3; Conference: 44. annual meeting of the American Society of Human Genetics, Montreal (Canada), 18-22 Oct 1994; Other Information: PBD: Sep 1994
- Country of Publication:
- United States
- Language:
- English
Similar Records
Mutation analysis of the RET gene in individuals with sporadic and familial pheochromocytoma
Frequent RET protooncogene mutations in multiple endocrine neoplasia Type 2A