title: Identification of somatic mutations in parathyroid tumors using whole-exome sequencing.
abstract: BACKGROUND
  The underlying molecular alterations causing sporadic parathyroid adenomas that drive primary hyperparathyroidism have not been thoroughly defined.
  
  
  OBJECTIVE
  The aim of the study was to investigate the occurrence of somatic mutations driving tumor formation and progression in sporadic parathyroid adenoma using whole-exome sequencing.
  
  
  METHODS
  Eight matched tumor-constitutional DNA pairs from patients with sporadic parathyroid adenomas underwent whole-exome capture and high-throughput sequencing. Selected genes were analyzed for mutations in an additional 185 parathyroid adenomas.
  
  
  RESULTS
  Four of eight tumors displayed a frame shift deletion or nonsense mutation in MEN1, which was accompanied by loss of heterozygosity of the remaining wild-type allele. No other mutated genes were shared among the eight tumors. One tumor harbored a Y641N mutation of the histone methyltransferase EZH2 gene, previously linked to myeloid and lymphoid malignancy formation. Targeted sequencing in the additional 185 parathyroid adenomas revealed a high rate of MEN1 mutations (35%). Furthermore, this targeted sequencing identified an additional parathyroid adenoma that contained the identical, somatic EZH2 mutation that was found by exome sequencing.
  
  
  CONCLUSIONS
  This study confirms the frequent role of the loss of heterozygosity of chromosome 11 and MEN1 gene alterations in sporadic parathyroid adenomas and implicates a previously unassociated methyltransferase gene, EZH2, in endocrine tumorigenesis.
authors: Department of Genetics, Yale Cancer Center, Yale University School of Medicine, New Haven, Connecticut 06520, USA.
authors: M Kyle
authors: MK
authors: Cromer
authors: Lee F
authors: LF
authors: Starker
authors: Murim
authors: M
authors: Choi
authors: Robert
authors: R
authors: Udelsman
authors: Carol
authors: C
authors: Nelson-Williams
authors: Richard P
authors: RP
authors: Lifton
authors: Tobias
authors: T
authors: Carling
mesh_terms: D000236:Adenoma / Q000235:genetics*; D015331:Cohort Studies; D004252:DNA Mutational Analysis; D004273:DNA, Neoplasm / Q000235:genetics*; D000071221:Enhancer of Zeste Homolog 2 Protein; D005091:Exons / Q000235:genetics*; D006801:Humans; D018761:Multiple Endocrine Neoplasia Type 1 / Q000235:genetics; D009154:Mutation / Q000235:genetics* / Q000502:physiology; D010282:Parathyroid Neoplasms / Q000235:genetics*; D063151:Polycomb Repressive Complex 2 / Q000235:genetics; D016133:Polymerase Chain Reaction; D015203:Reproducibility of Results; D017422:Sequence Analysis, DNA
chemical_list: D004273:DNA, Neoplasm; C498409:EZH2 protein, human; D000071221:Enhancer of Zeste Homolog 2 Protein; D063151:Polycomb Repressive Complex 2