Whole-Exome Sequencing Studies of Parathyroid Carcinomas Reveal Novel PRUNE2 Mutations, Distinctive Mutational Spectra Related to APOBEC-Catalyzed DNA Mutagenesis and Mutational Enrichment in Kinases Associated With Cell Migration and Invasion

Context: Cell division cycle 73 (CDC73), encoding the protein parafibromin, is the most prevalent mutated gene in familial and sporadic parathyroid carcinoma (PC). Objective: To identify additional genetic abnormalities in PCs. Design: Whole-exome sequencing was performed using DNA from seven pairs of matched PCs and one triplet containing double primary tumor and normal leukocyte. Somatic variants were confirmed using Sanger sequencing and recurrently mutated genes were assessed in 13 additional PCs as well as 40 parathyroid adenomas (PA). Results: PC had an average of 51 somatic variants/tumor (range 3–176) with approximately 58% of variants occurring as nonsynonymous single nucleotide variants. The importance of CDC73 in PC is reinforced with a remarkable preferential amplification of the mutant CDC73 allele. Furthermore, recurrent germ line and somatic mutations in prune homolog 2 [Drosophila] (PRUNE2) were found in PC and computationally predicted to be deleterious; in addition, recurrent mutations i...