Abstract PurposeTo 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.MethodsClinical information of one female patient as well as five of her relatives were 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.ResultsThe medical history of recurrent hypercalcemia after parathyroidectomy and histopathological investigation confirmed that the female patient with the diagnosis of PC. WGS displayed a novel 130kb long-range deletion spanning UCHL5 to CDC73 which 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.ConclusionWe discovered a novel 130kb long-range deletion spanning CDC73 in a family of five-person, 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.