Absence of Stabilizing Mutations of β-Catenin Encoded by CTNNB1 Exon 3 in a Large Series of Sporadic Parathyroid Adenomas

CONTEXT: The molecular mechanisms underlying the pathogenesis of sporadic parathyroid adenomas are incompletely understood. Dysfunction of the Wnt signaling pathway is an established pathogenetic contributor to human tumorigenesis and, recently, the role of stabilizing mutations in beta-catenin, a cause of abnormal Wnt signaling, has been examined in parathyroid tumors with conflicting results. OBJECTIVE: The objective of the present study was to determine the frequency of stabilizing mutations in exon 3 of CTNNB1, encoding beta-catenin, in a large series of parathyroid adenomas. PATIENTS AND DESIGN: Ninety-seven sporadic parathyroid adenomas were examined for mutations in exon 3 of CTNNB1 by direct DNA sequencing. RESULTS: No mutations were identified in any of the adenomas. CONCLUSIONS: The absence of stabilizing mutations of beta-catenin, including the previously reported S37A, encoded in CTNNB1 exon 3 among 97 tumors suggests that such mutations contribute rarely if at all to the development of sporadic parathyroid adenomas. A primary role for abnormal Wnt signaling in parathyroid tumor formation remains to be established.