A novel long-range deletion spanning CDC73 and upper-stream genes discovered in a kindred of familial primary hyperparathyroidism.

Yi Yang,Xiaoping Xing,An Song,Ya Hu,Weibo Xia,Min Nie,Mei Li,Ou Wang,Yan Jiang

doi:10.1007/s12020-021-02917-5

Abstract

To confirm the exact break-point of a novel long-range deletion discovered in one female parathyroid carcinoma (PC) patient who has a strong family history suggesting familial hyperparathyroidism, and to investigate the expression of parafibromin in the patient's affected lesion. Clinical information of one female patient as well as five of her relatives was collected. Their genomic DNA extracted from peripheral blood went through Sanger sequencing and multiplex ligation-dependent probe amplification (MLPA). After completing whole genome sequencing (WGS), clone sequencing was also performed, whose result was aligned with standard human genome database after Sanger sequencing. The medical history of recurrent hypercalcemia after parathyroidectomy and histopathological investigation confirmed that the female patient was diagnosed with PC. WGS displayed a novel 130 kb long-range deletion spanning UCHL5 to CDC73 that was later confirmed by clone sequencing. MLPA showed similar results in four of her five relatives, suggesting these people to be carriers of the same long-range deletion, and three among them had a history of primary hyperparathyroidism (PHPT) ahead of the proband's first visit. We discovered a novel 130 kb long-range deletion spanning CDC73 in a family of 5 persons, and the existence of the deletion was related to PHPT and PC. Our discovery validated the role of CDC73 mutation in the occurrence of PHPT and PC, which provided new information to the genetic studies of PC.

Highlights

Primary hyperparathyroidism (PHPT), as the third most frequent endocrine disorder in western countries, is a metabolic bone disease caused by autonomous excessive parathyroid hormone (PTH)
The medical history of recurrent hypercalcemia after parathyroidectomy and histopathological investigation confirmed that the female patient with the diagnosis of Parathyroid carcinoma (PC)
multiplex ligation-dependent probe amplification (MLPA) showed similar results in four of her five relatives, suggesting these people to be carriers of the same long-range deletion, and three among them had a history of primary hyperparathyroidism (PHPT) ahead of the proband’s first visit

Summary

Introduction

Primary hyperparathyroidism (PHPT), as the third most frequent endocrine disorder in western countries, is a metabolic bone disease caused by autonomous excessive parathyroid hormone (PTH). Parathyroid carcinoma (PC) is a rare pathologic type which comprises 0.5%–5% of patients with PHPT[1][2][3]. PC is commonly sporadic, but it can be a part of specific syndromes in familial PHPT including multiple endocrine neoplasia type 1 (MEN1) and 2A (MEN2A)[4], the hyperparathyroidism-jaw tumor syndrome (HPT-JT)[5][6]. Germline mutations of the CDC73 (located in 1q32.1, initially named HRPT2) gene was initially associated with HPT-JT[7][6]. In 15%–70% of sporadic PC cases, CDC73 mutations were found to be somatic, and in onethird of them, such mutations are found as germline[8]

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Conclusion