Predictive DNA testing for multiple endocrine neoplasia 2: a therapeutic challenge of prophylactic thyroidectomy in very young children.
BACKGROUND
Patients with multiple endocrine neoplasia (MEN) type 2 are at risk for early medullary thyroid carcinoma (MTC). Recently, the cloning of the ret oncogene has made it possible to identify patients at risk for MEN 2 syndrome with a high degree of reliability before presenting any symptoms.


METHODS
Children of families with MEN 2 were screened genetically if one of the parents was a known gene carrier of the RET proto-oncogene. If they were carriers, thyroidectomy was performed.


RESULTS
The authors report five children with MEN 2 who underwent prophylactic thyroidectomy irrespective of the results of calcitonin screening tests after genetic screening had shown that they were carrier of the RET proto-oncogene. Apart from a temporary hypocalcemia in one, the operations were uneventful. Pathology results showed MTC in three children of one family with MEN 2A at age 2, 3, and 6 years. In two families with MEN 2B the thyroidectomy specimen showed bilateral MTC in a 1-year-old and a 3-year-old child.


CONCLUSIONS
These findings show that MTC occurs at very young age in children with MEN 2. The authors advocate performing prophylactic thyroidectomy in the first year of life in children with MEN 2B and at age 2 years in children with MEN 2A to obtain an optimal cure rate.
van Heurn
L W
LW
Department of Surgery, University Hospital of Maastricht, The Netherlands.
Schaap
C
C
Sie
G
G
Haagen
A A
AA
Gerver
W J
WJ
Freling
G
G
van Amstel
H K
HK
Heineman
E
E
D018276:Carcinoma, Medullary / Q000235:genetics / Q000517:prevention & control*; D002648:Child; D004252:DNA Mutational Analysis; D005260:Female; D006580:Genetic Carrier Screening; D006801:Humans; D007223:Infant; D008297:Male; D018813:Multiple Endocrine Neoplasia Type 2a / Q000235:genetics*; D018814:Multiple Endocrine Neoplasia Type 2b / Q000235:genetics*; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D011519:Proto-Oncogenes / Q000235:genetics*; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics; D013964:Thyroid Neoplasms / Q000235:genetics / Q000517:prevention & control*; D013965:Thyroidectomy
C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins; D020794:Receptor Protein-Tyrosine Kinases