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Fumarate hydratase (FH) catalyzes the conversion of fumaric acid to L‐malic acid. Heterozygous variants of the human fumarate hydratase gene (FH) predispose to hereditary leiomyomatosis and renal cell cancer and, rarely, pheochromocytoma/paraganglioma (PPGL). No mosaic variant in FH has been reported yet. Using next‐generation sequencing, five individuals with FH variants were found in 319 PPGL patients. Immunohistochemistry staining and loss of heterozygosity analysis in tumor tissues were performed to determine the pathogenicity of the variants. Deep targeted sequencing was performed on the peripheral blood DNA of a pheochromocytoma (PCC) patient with uterine leiomyomas. Finally, two of the five variants were found to be pathogenic. A germline variant (c.817G>A, p.Ala273Thr) was found in a patient with a PPGL family history. A mosaic variant (c.206G>A, p.Gly69Asp) with an allelic ratio of 5% in blood DNA was confirmed in the PCC patient with uterine leiomyomas. No metastatic PPGL was observed in the two PPGL patients with FH pathogenic variants. In summary, we report mosaicism in FH and the first PPGL pedigree with an FH pathogenic germline variant. Both germline variants and mosaicism should be taken into account during genetic testing.

BackgroundPrevious studies have investigated the transcriptional modulations of aldosterone overproduction of aldosterone-producing adenomas (APAs), and several potential genes were found with high expressions. PurposeWe aimed to systematically study the genes and pathways associated with molecular mechanism underlying APA by bioinformatics analysis and experimental validation for the expression profile. MethodsThis study was performed based on three gene expression profiles (GSE64957, GSE8514, and GSE60042). Differentially expressed gene (DEG) investigation, function and pathway enrichment, as well as protein-protein interaction (PPI) network, were performed by the bioinformatics analysis. For the validation with quantitative PCR, tissues from 11 patients with non-functioning adrenal adenoma (NFA) and 13 with APA were included in our cohort. ResultsIn this study, the bioinformatics analysis was performed and 182 upregulated and 88 downregulated DEGs were identified. As expected, the upregulated DEGs were primarily involved in calcium ion homeostasis (GO: 0055074, n = 3, p = 2.00X10-4). In the KEGG pathway analysis, calcium signaling pathway (hsa04020, n = 8, p= 4.38X10-6) and the aldosterone synthesis and secretion (hsa04925, n = 6, p = 8.73X10-6) were enriched. Moreover, quantitative PCR was performed to detect the expression of 7 upregulated genes (PCP4, ATP2A3, CYP11B2, CLCN5, HTR4, VDR and AQP2) among the intersection of DEGs. The mRNA levels of CYP11B2, HTR4 and AQP2 were significantly increased in APA samples compared to NFA (24.420 folds of NFA, p<0.001, 3.753 folds of NFA, p=0.002 and 11.487 folds of NFA, p=0.018).ConclusionIn summary, the present study showed several candidate genes with high expression from bioinformatics analysis and our cohort. And the DEGs were enriched in aldosterone synthesis and secretion and calcium signaling pathway as expected.

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.