Multiple Endocrine Neoplasia type 2A (MEN 2A) is characterized by medullary thyroid cancer, pheochromocytoma, and primary hyperparathyroidism, all caused by germline mutations in which gene?

• A RET proto-oncogene on chromosome 10q11 ✓
• B MEN1 (menin gene) on chromosome 11q13
• C CDKN1B (p27) gene on chromosome 12p13
• D PTEN tumor suppressor gene on chromosome 10q23

Explanation

MEN 2A (and 2B) are caused by activating missense mutations in the RET proto-oncogene (chromosome 10q11), which encodes a receptor tyrosine kinase. Specific codon mutations (codons 609, 611, 618, 620 in exon 10; codon 634 in exon 11) correlate with MEN 2A risk categories. MEN1 (Werner syndrome) is caused by mutations in the menin gene on 11q13. The American Thyroid Association risk stratification of RET mutations guides the timing of prophylactic thyroidectomy (as early as 6 months for highest-risk D codon 918 mutations in MEN 2B).

Reference: Bailey & Love's Short Practice of Surgery, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.