title: Predictive DNA testing for multiple endocrine neoplasia 2: a therapeutic challenge of prophylactic thyroidectomy in very young children.
abstract: 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.
authors.affiliation: Department of Surgery, University Hospital of Maastricht, The Netherlands.
authors.forename: L W
authors.initials: LW
authors.lastname: van Heurn
authors.forename: C
authors.initials: C
authors.lastname: Schaap
authors.forename: G
authors.initials: G
authors.lastname: Sie
authors.forename: A A
authors.initials: AA
authors.lastname: Haagen
authors.forename: W J
authors.initials: WJ
authors.lastname: Gerver
authors.forename: G
authors.initials: G
authors.lastname: Freling
authors.forename: H K
authors.initials: HK
authors.lastname: van Amstel
authors.forename: E
authors.initials: E
authors.lastname: Heineman
mesh_terms: 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
chemical_list: C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins; D020794:Receptor Protein-Tyrosine Kinases