Question

Genetic testing in medullary thyroid cancer.

Hint:

Genetic testing for RET mutations in medullary thyroid cancer is crucial to identify familial cases and guide early intervention.

Answer 1

Genetic testing in medullary thyroid cancer (MTC) is important for identifying hereditary forms of the disease and for guiding treatment and management. The key aspects of genetic testing in MTC include:
1. RET Proto-Oncogene Mutation Testing:
- The majority of sporadic MTC cases are not inherited, but familial MTC is often caused by mutations in the RET (Rearranged during Transfection) proto-oncogene.
- RET mutation testing is recommended for all patients with MTC to determine if they have a hereditary form, specifically Multiple Endocrine Neoplasia type 2 (MEN 2).
2. MEN 2 Subtypes:
- MEN 2A: Associated with MTC, pheochromocytoma, and parathyroid adenomas.
- MEN 2B: A more aggressive form that includes MTC, pheochromocytoma, and marfanoid habitus.
3. Significance of Genetic Testing:
- Positive results for RET mutations help identify at-risk family members who can undergo prophylactic thyroidectomy to prevent the development of MTC.
- Genetic testing is crucial for early detection and surgical intervention, especially in children of affected individuals, to prevent the onset of MTC.