0
Correspondence and Brief Communications |

RET Proto-oncogene Mutation Analysis for Multiple Endocrine Neoplasia, Type 2

Hiroshi Takami, MD
[+] Author Affiliations

Not Available


Copyright 1998 American Medical Association. All Rights Reserved. Applicable FARS/DFARS Restrictions Apply to Government Use.

More Author Information
Arch Surg. 1998;133(6):679-679. doi:10.1001/archsurg.133.6.679
Text Size: A A A
Published online

We read with interest the article by Learoyd et al1 concerning genetic testing for multiple endocrine neoplasia, type 2 (MEN 2). We generally agree with the conclusion of this article, but hold a different opinion in regard to the following. The authors state that genetic screening for RET proto-oncogene mutations in MEN 2 is a powerful diagnostic tool and that RET mutation carriers older than 6 years of age should undergo thyroidectomy immediately.

We investigated the spectrum of RET mutations among patients with MEN 2, familial medullary thyroid carcinoma (FMTC), and sporadic medullary thyroid carcinoma (MTC).2 Mutations in nucleotide sequences encoding 1 of 3 specific cysteine residues in the extracellular domain of RET protein were found in 37 of the 38 MEN 2A families and 3 of the 4 FMTC families examined. A mutation at codon 918 was found in the germline DNA of all 5 patients with MEN 2B and in 8 of 22 tumors in patients with sporadic MTC. We detected 4 de novo mutations at codon 634, TGC to TAC or CGC (Cys to Tyr or Arg), and codon 918, ATG to ACG (Met to Thr). We also identified 2 novel somatic mutations in patients with sporadic MTC, 1 at codon 631 (Asp to Gly) and the other at codon 634 (Cys to Arg). Here, I would like to stress that our data show that specific mutations of the RET proto-oncogene are related to the disease phenotype in MEN 2A and FMTC. For example, there is an association between all mutations at codon 634 and pheochromocytoma and parathyroid disease. Mutations at codon 764 and 804 are specific to FMTC. Patients with mutations at codon 634 have a higher recurrence rate than patients with mutations at other codons. The phenotype of the disease and the outcome have been found to vary considerably according to the codon that has mutated. We therefore think that the decision as to the timing of surgery should be based on the site of the mutated codon and estimation of the degree of malignancy of the disease. Because of the possibility of lymph node metastases occurring once MEN 2A patients reach age 6 years, we think that the standard guideline should be to perform thyroidectomy at no later than 5 years of age.

REFERENCES

Learoyd  DL, Marsh  DJ, Richardson  A-L, Twigg  SM, Delbridge  L, Robinson  BG. Genetic testing for familial cancer: consequences of RET proto-oncogene mutation analysis in multiple endocrine neoplasia, type 2. Arch Surg. 1997;1321022- 1025
Takiguchi-Shirahama  S, Koyama  K, Takami  H.  et al.  Germline mutations of the RET proto-oncogene in eight Japanese patients with multiple endocrine neoplasia type 2A (MEN 2A). Hum Genet. 1995;95187- 190

First Page Preview

First page PDF preview

Figures

Tables

Interactive Graphics

Video

Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

Learoyd  DL, Marsh  DJ, Richardson  A-L, Twigg  SM, Delbridge  L, Robinson  BG. Genetic testing for familial cancer: consequences of RET proto-oncogene mutation analysis in multiple endocrine neoplasia, type 2. Arch Surg. 1997;1321022- 1025
Takiguchi-Shirahama  S, Koyama  K, Takami  H.  et al.  Germline mutations of the RET proto-oncogene in eight Japanese patients with multiple endocrine neoplasia type 2A (MEN 2A). Hum Genet. 1995;95187- 190

Correspondence

CME Course for:


You need to register in order to view this quiz.


To understand the clinical management of acute heart failure syndromes.
Accreditation Information The American Medical Association is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.
The AMA designates this journal-based CME activity for a maximum of 1 AMA PRA Category 1 CreditTM per course. Physicians should claim only the credit commensurate with the extent of their participation in the activity.
Physicians who complete the CME course and score at least 80% correct on the quiz are eligible for AMA PRA Category 1 CreditTM.
Note: You must get at least of the answers correct to pass this quiz.
Note: You must get at least of the answers correct to pass this quiz.
You have not filled in all the answers to complete this quiz
The following questions were not answered:
Sorry, you have unsuccessfully completed this CME quiz with a score of
The following questions were not answered correctly:
For CME Course: A Proposed Model for Initial Assessment and Management of Acute Heart Failure Syndromes
Indicate what changes(s) you will implement in your practice, if any, based on this CME course.
To view and print your certificate and access a summary of your CME courses go to My CME.
NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s “Cited By” API will populate this tab (http://www.crossref.org/citedby.html).
Submit a Comment

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging & repositioning the boxes below.

Articles Related By Topic
Related Topics
PubMed Articles