Multiple endocrine neoplasias type 2B and RET proto-oncogene

Area of Science:

• Oncology
• Genetics
• Pediatrics

Background:

• Multiple Endocrine Neoplasia type 2B (MEN 2B) is a rare, autosomal dominant neurocristopathy characterized by medullary thyroid carcinoma, pheochromocytoma, and ganglioneuromas.
• Medullary thyroid carcinoma (MTC) is the primary cause of mortality in MEN 2B, often manifesting in early childhood.
• Activating germline mutations in the RET proto-oncogene are the genetic basis for MEN 2B, with the M918T mutation in exon 16 occurring in 95% of cases.

Purpose of the Study:

• To highlight the genetic basis of MEN 2B and the importance of early diagnosis.
• To emphasize the role of RET proto-oncogene mutations in MEN 2B pathogenesis and predisposition.
• To discuss diagnostic standards and prophylactic surgical interventions for MEN 2B.

Main Methods:

• Review of existing literature on MEN 2B, RET proto-oncogene mutations, and diagnostic approaches.
• Discussion of diagnostic standards including acetylcholinesterase studies and molecular analysis of RET.
• Description of prophylactic surgical treatment, specifically total thyroidectomy with central compartment lymphadenectomy.

Main Results:

• RET proto-oncogene mutations are causative for MEN 2B, with specific mutations identified in exon 16 (M918T) and codon 883.
• RET gene mutations are implicated in various neurocristopathies, including MEN 2A and Hirschsprung's disease.
• Early diagnosis via RET mutation detection enables pre-clinical identification and prophylactic thyroidectomy before age one.

Conclusions:

• Early molecular genetic diagnosis of MEN 2B predisposition is crucial for timely prophylactic thyroidectomy.
• Advances in understanding RET proto-oncogene signaling pathways may lead to novel therapeutic strategies for MEN 2B and MTC.
• Rectal biopsy and RET mutation analysis are key diagnostic tools for MEN 2B.