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Hyperparathyroidism jaw-tumor syndrome is an autosomal dominant disorder caused by mutations in the CDC73/HRPT2 tumor suppressor gene, encoding parafibromin, and manifesting benign or malignant parathyroid tumors, ossifying jaw fibromas, uterine tumors, and kidney lesions. Sporadic parathyroid carcinomas also frequently exhibit inactivating CDC73 mutations and loss of parafibromin. To study the role of CDC73 in parathyroid cell proliferation in vivo, we generated mice with a parathyroid-specific deletion of Cdc73. Homozygous knockout mice on a mixed B6/129/CD1 background had decreased serum calcium and PTH and smaller parathyroid glands compared with heterozygous or wild-type littermates, whereas homozygous Cdc73 -null mice on other backgrounds exhibited no abnormalities in parathyroid gland function or development. No hypercalcemia or parathyroid hypercellularity was observed in mice of any background examined at any age. Thus, although postnatally acquired complete loss of CDC73 causes parathyroid cell proliferation and hyperparathyroidism, such as seen in human hyperparathyroidism jaw-tumor syndrome, our results suggest that earlier, developmentally imposed complete loss of Cdc73 can cause a primary defect in parathyroid gland structure/function in a strain-dependent manner. This striking disparity in parathyroid phenotype related to genetic background offers a unique opportunity in an in vivo model system to precisely dissect and identify the responsible molecular mechanisms. [ABSTRACT FROM AUTHOR]

Background: Hereditary primary hyperparathyroidism (PHPT) accounts for 5-10% of all PHPT cases, necessitating genetic testing for diagnosis and management. Among these, hyperparathyroidism-jaw tumor syndrome (HPTJT) is an autosomal dominant disorder caused by CDC73 mutations with variable clinical presentations and incomplete symptoms. Case summary: The proband, diagnosedwith PHPT, underwent parathyroidectomy at the age of 41 with pathological examination of parathyroid carcinoma (PC). Hereditary PHPT was initially suspected due to the early-onset PHPT and family history. Genetic testing identified a heterozygous CDC73 mutation, NM_024529.4: c. 687_688delAG (p. Arg229Serfs*37). Even in the absence of jaw tumors, the diagnosis of HPT-JT was confirmed based on the discovery of renal cysts. A secondary thyroidectomy was performed to reduce the risk of recurrence. Conclusion: Genetic testing is strongly recommended in cases of early-onset PHPT, family history, jaw tumors, renal and uterine involvement, atypical parathyroid tumors, and PC. This testing provides valuable information for personalized management, and counseling is available for affected families. [ABSTRACT FROM AUTHOR]

Between 2% and 10% of patients with primary hyperparathyroidism (pHPT) are diagnosed with hereditary forms of primary hyperparathyroidism (hpHPT). They are more prevalent in younger patients before the age of 40 years, in patients with persistence or recurrence of pHPT and pHPT patients with multi-glandular disease (MGD). The various forms of hpHPT diseases can be classified into four syndromes, i.e., hpHPT associated with diseases of other organ systems, and four diseases that are confined to the parathyroid glands. Approximately 40% of patients with hpHPT suffer from multiple endocrine neoplasia type 1 (MEN-1) or show germline mutations of the MEN‑1 gene. Currently, germline mutations that lead to a specific diagnosis in patients with hpHPT have currently been described in 13 different genes, which enables a clear diagnosis of the disease; however, a clear genotype-phenotype correlation does not exist, even though the complete loss of a coded protein (e.g. due to frame-shift mutations in the calcium sensing receptor, CASR) often leads to more severe clinical consequences than merely a reduced function of the protein (e.g. due to point mutation). As the various hpHPT diseases require different treatment approaches, which do not correspond to that of sporadic pHPT, a clear definition of the specific form of hpHPT must always be strived for. Therefore, before surgery of a pHPT with clinical, imaging or biochemical suspicion of hpHPT, genetic proof or exclusion of hpHPT is necessary. The differentiated treatment approach for hpHTP can only be defined by taking the clinical and diagnostic results of all the abovenamed findings into account. [ABSTRACT FROM AUTHOR]

Hyperparathyroidism-jaw tumor syndrome is a rare disorder that is inherited in an autosomal dominant manner and predisposes to the development of parathyroid adenomas and carcinoma, ossifying jaw tumors, uterine neoplasms and renal cysts. It is caused by inactivating mutations in the gene CDC73 that it was first identified in 2002. The purpose of this narrative review is to highlight the genetic background of the syndrome and its clinical manifestations as well as to emphasize the significance of genetic testing in diagnosis from an early age. The clinical and familial features of the syndrome were collected by searching on electronic database PubMed/Medline using the MeSH terms "Hyperparathyroidism-jaw tumor syndrome" or "HPT-JT syndrome". 246 articles were returned of which, 44 were reviews and 59 case reports. Two nationwide retrospective studies were found. This article is focused mainly on data from the last decade, as there seems to be a better understanding of the genetic basis due to the evolution of DNA sequencing techniques. To date, there have been over 200 patients reported in approximately 50 families carrying a germline mutation of CDC73 gene, suggesting that there should be an augmented awareness of identifying both patients and their relatives. [ABSTRACT FROM AUTHOR]

Background/purpose: Hyperparathyroidism-jaw tumor syndrome is a rare autosomal dominant disease characterized by parathyroid tumors and ossifying fibroma of the jaw. Disease-causing mutations have been localized in the tumor suppressor gene CDC73. This study is designed to highlight the importance of genetic testing in the diagnosis of ossifying fibroma related to this syndrome. Materials and methods: The Clinical, histopathological, radiographical, familial and genetic features of 24 patients with Hyperparathyroidism-jaw tumor syndrome were collected by searching the electronic literature PubMed, Medline, Embase, and Science Direct databases combining the MeSH heading terms “Hyperparathyroidism jaw tumor syndrome”, with the words “Ossifying fibroma” and “CDC73”. The collected features were simply assessed and analyzed. Results: The average age was 28.68 years old (age range 10–66), with 12 male and 12 female patients (1:1 M/F ratio). Hyperparathyroidism results from parathyroid adenoma in 16/24 cases (66.666%) and parathyroid carcinome in 5/24 (20.833%). Bone pathology occurred most often in the mandible (16/24 cases; 66.666%), while 5/24 cases were in the maxilla (20.883%) and 3 cases in both (12.5%). In 5/24 cases, ossifying fibroma was the first to occur before hypercalcemia. Genetic mutation of CDC73 were positive in 19/24 cases (79.166%). Conclusion: Since the jaw lesions in Hyperparathyroidism-jaw tumor syndrome could proceed the cardinal signs of hyperparathyroidism, its accurate diagnosis needs to depend on clinical, histological, radiographical, family history and most of all the genetic testing for CDC73 gene.

Ossifying fibromas are very rare tumors that are sometimes seen as part of the hyperparathyroidism-jaw tumor syndrome (HPT-JT), which is caused by inactivating mutations of the HRPT2/CDC73 tumor suppressor gene. CDC73 mutations have been identified in a subset of sporadic cases but aberrant expression of the encoded protein, parafibromin, has not been demonstrated in ossifying fibroma. We sought to determine if loss of parafibromin regularly contributes to the development of sporadic, nonsyndromic ossifying fibroma. We examined a series of 9 ossifying fibromas, including ossifying, cemento-ossifying, and juvenile active variants, for parafibromin protein expression by immunohistochemistry and for CDC73 sequence abnormalities by Sanger sequencing and/or targeted AmpliSeq panel sequencing. Four ossifying fibromas showed a complete absence of nuclear parafibromin expression; loss of parafibromin expression was coupled with aberrant cytoplasmic parafibromin expression in 1 case. CDC73 mutations were detected in 2 cases with aberrant parafibromin expression. These results provide novel evidence, at the level of protein expression, that loss of the parathyroid CDC73 /parafibromin tumor suppressor may play a role in the pathogenesis of a subset of ossifying fibromas. [ABSTRACT FROM AUTHOR]

Context: Parathyroid cancer has been linked to germline mutations of the CDC73 gene. However, carriers harboring cancer-associated germline CDC73 mutations may develop only parathyroid adenoma or no parathyroid disease. This incomplete penetrance indicates that additional genomic events are required for parathyroid tumorigenesis., Objective: (1) Determine the status of the second CDC73 allele in parathyroid tumors harboring germline CDC73 mutations, and (2) compare the genomic landscapes between parathyroid carcinomas and adenomas., Design: Whole-exome and RNA sequencing of 12 parathyroid tumors harboring germline CDC73 mutations (6 adenomas and 6 carcinomas) and their matched normal tissues., Results: All 12 parathyroid tumors had gained one somatic event predicted to cause a complete inactivation of the second CDC73 allele. Several distinctive genomic features were identified in parathyroid carcinomas compared to adenomas, including more single nucleotide variants bearing the C>G transversion and APOBEC deamination signatures, frequent mutations of the genes involved in the PI-3K/mTOR signaling, a greater number of copy number variations, and substantially more genes with altered expression. Parathyroid carcinomas also share some genomic features with adenomas. For instance, both have recurrent somatic mutations and copy number loss that impact the genes involved in T-cell receptor signaling and tumor antigen presentation, suggesting a shared strategy to evade immune surveillance., Conclusions: Biallelic inactivation of CDC73 is essential for parathyroid tumorigenesis in carriers harboring germline mutations of this gene. Despite sharing some genomic features with adenomas, parathyroid carcinomas have more distinctive alterations in the genome, some of which may be critical for cancer formation., (Published by Oxford University Press on behalf of the Endocrine Society 2024.)

Primary hyperparathyroidism (PHPT) is sporadic in the majority of cases. Hereditary forms of PHPT are rarer, however, they are of particular interest because they allow a deeper understanding of pathogenesis of parathyroid neoplasia. Hereditary forms of PHPT include multiple endocrine neoplasia type 1 (MEN-1), type 2A (MEN-2A), type 4 (MEN-4), hyperparathyroidism-jaw tumour syndrome (HPT-JT), variants of familial hypocalciuric hypercalcemia (FHH) and familial isolated hyperparathyroidism (FIHP). Mutations in the following genes cause the development of MEN-1, MEN-2A, MEN4, HPT-JT: MEN1, RET, CDKN1B, CDC73, respectively. Variants of FHH are caused by mutations in CASR, AP2S1, GNA11. Gene(s) responsible for the development of the majority of FIHP cases remain unknown. Identification of hereditary forms of PHPT is important for patients and their first-degree relatives, as it allows defining the necessity of screening to reveal other components of the syndrome, in some cases determines the surgical approach to PHPT, and the risk of development of the disease in offsprings. This article provides information on hereditary syndromes associated with PHPT and special features of PHPT in each syndrome.

Hyperparathyroidism-jaw tumor syndrome is a rare autosomal dominant disease characterized by parathyroid tumors and ossifying fibroma of the jaw. Disease-causing mutations have been localized in the tumor suppressor gene CDC73. This study is designed to highlight the importance of genetic testing in the diagnosis of ossifying fibroma related to this syndrome. The Clinical, histopathological, radiographical, familial and genetic features of 24 patients with Hyperparathyroidism-jaw tumor syndrome were collected by searching the electronic literature PubMed, Medline, Embase, and Science Direct databases combining the MeSH heading terms "Hyperparathyroidism jaw tumor syndrome", with the words "Ossifying fibroma" and "CDC73". The collected features were simply assessed and analyzed. The average age was 28.68 years old (age range 10–66), with 12 male and 12 female patients (1:1 M/F ratio). Hyperparathyroidism results from parathyroid adenoma in 16/24 cases (66.666%) and parathyroid carcinome in 5/24 (20.833%). Bone pathology occurred most often in the mandible (16/24 cases; 66.666%), while 5/24 cases were in the maxilla (20.883%) and 3 cases in both (12.5%). In 5/24 cases, ossifying fibroma was the first to occur before hypercalcemia. Genetic mutation of CDC73 were positive in 19/24 cases (79.166%). Since the jaw lesions in Hyperparathyroidism-jaw tumor syndrome could proceed the cardinal signs of hyperparathyroidism, its accurate diagnosis needs to depend on clinical, histological, radiographical, family history and most of all the genetic testing for CDC73 gene. [ABSTRACT FROM AUTHOR]

This report summarizes published data on parathyroid cancer, with the inclusion of topics discussed at MEN2019: 16th International Workshop on Multiple Endocrine Neoplasia, 27-29 March 2019, Houston, TX, USA. An expert panel on parathyroid cancer was constituted by the Steering Committee to address key questions in the field. The objectives were to recap open forum discussion of interested parties from multiple disciplines. The expert panel met in a closed session to consul t on the data to be highlighted on the evidence-based results and on the future directions. Preceding the Conference, members of the expert panel conducted an extensive literature search. All presentations were based upon the best peer-reviewed information taking into account the historical and current literature. Questions were developed by the expert panel on parathyroid carcinoma. A comprehensive literature search for relevant studies was undertaken. This report represents the expert panel's synthesis of the conference material placed in a context designed to be relevant to clinici ans and those engaged in cutting-edge studies of parathyroid carcinoma. This document not only provides a summary of our current knowledge but also places recent advances in its management into a context that should enhance future advances in our under standing of parathyroid carcinoma. [ABSTRACT FROM AUTHOR]

Purpose: Previously in 1987, a 21-year-old male was diagnosed with primary hyperparathyroidism (PHPT) when a right inferior parathyroid adenoma was removed. PHPT recurred after 3 and 6 years and on both occasions was cured by resection of parathyroid adenomas. At 52 years of age, the patient developed a late-onset hypoparathyroidism (HP), even though postsurgical HP typically occurs as a transient or permanent form soon after neck surgery. The purpose of this work was to report the follow-up of the patient and to review prior cases of late-onset postsurgical HP. Methods: Prior cases of late-onset postsurgical HP were searched and reviewed focusing on clinical and biochemical features. Results: The patient's asymptomatic hypocalcemia with total serum calcium at 8.2 mg/dL was initially documented in September 2018; PTH was inappropriately low at 15 ng/mL. In February 2020, a mild hypocalcemia was confirmed with low-normal PTH at 15 ng/mL. Autoimmune and familial causes of HP were ruled out including the presence of stimulating autoantibodies against calcium-sensing receptor. Instead, a progressive damage or atrophy of the parathyroid gland(s) ensuing years after surgery is believed to have led to the patient's hypocalcemia. All 19 previously reported cases of late-onset postsurgical HP occurred after thyroid surgery, with no examples of the condition being found following parathyroidectomy. Conclusions: The case highlights the rare occurrence of late-onset postsurgical HP in a patient who had had multiple parathyroidectomies for PHPT. Thus, monitoring serum calcium, phosphate, and PTH during follow-up of such patients is recommended. [ABSTRACT FROM AUTHOR]

While somatic disruptive mitochondrial DNA (mtDNA) mutations that severely affect the respiratory chain are counter-selected in most human neoplasms, they are the genetic hallmark of indolent oncocytomas, where they appear to contribute to reduce tumorigenic potential. A correlation between mtDNA mutation type and load, and the clinical outcome of a tumor, corroborated by functional studies, is currently lacking. Recurrent familial oncocytomas are extremely rare entities, and they offer the chance to investigate the determinants of oncocytic transformation and the role of both germline and somatic mtDNA mutations in cancer. We here report the first family with Hyperparathyroidism-Jaw Tumor (HPT-JT) syndrome showing the inherited predisposition of four individuals to develop parathyroid oncocytic tumors. MtDNA sequencing revealed a rare ribosomal RNA mutation in the germline of all HPT-JT affected individuals whose pathogenicity was functionally evaluated via cybridization technique, and which was counter-selected in the most aggressive infiltrating carcinoma, but positively selected in adenomas. In all tumors different somatic mutations accumulated on this genetic background, with an inverse clear-cut correlation between the load of pathogenic mtDNA mutations and the indolent behavior of neoplasms, highlighting the importance of the former both as modifiers of cancer fate and as prognostic markers.

Background: Primary hyperparathyroidism (PHPT) is a relatively rare disorder among children, adolescents and young adults. Its development at an early age is suspicious for hereditary causes, though the need for routine genetic testing remains controversial. Objective: To identify and describe hereditary forms of PHPT in patients with manifestation of the disease under 40 years of age. Design: We enrolled 65 patients with PHPT diagnosed before 40 years of age. Ten of them had MEN1 mutation, and PHPT in them was the first manifestation of multiple endocrine neoplasia type 1 syndrome. Methods: The other fifty-five patients underwent next-generation sequencing (NGS) of a custom-designed panel of genes, associated with PHPT (MEN1, CASR, CDC73, CDKN1A, CDKN1B, CDKN1C, CDKN2A, CDKN2C, CDKN2D). In cases suspicious for gross CDC73 deletions multiplex ligation-dependent probe amplification was performed. Results: NGS revealed six pathogenic or likely pathogenic germline sequence variants: four in CDC73 c.271C>T (p.Arg91*), c.496C>T (p.Gln166*), c.685A>T (p.Arg229*) and c.787C>T (p.Arg263Cys); one in CASR c.3145G>T (p.Glu1049*) and one in MEN1 c.784-9G>A. In two patients, MLPA confirmed gross CDC73 deletions. In total, 44 sporadic and 21 hereditary PHPT cases were identified. Parathyroid carcinomas and atypical parathyroid adenomas were present in 8/65 of young patients, in whom CDC73 mutations were found in 5/8. Conclusions: Hereditary forms of PHPT can be identified in up to 1/3 of young patients with manifestation of the disease at

Primary hyperparathyroidism (PHPT) is a rare endocrine disease in the pediatric population. Sporadic parathyroid adenomas remain the most common cause of pediatric PHPT. Parathyroid carcinoma (PC) is an extremely rare cause of pediatric PHPT. We report a 16-year-old boy presenting with a nonhealing fragility fracture of the right leg along with florid features of rickets. Examination revealed a neck mass, mimicking a goiter. Biochemical findings were consistent with PHPT. Imaging was suggestive of a right inferior parathyroid mass infiltrating the right lobe of thyroid. The patient underwent en bloc surgical excision of the parathyroid mass along with the right lobe of thyroid. Histopathology was suggestive of a PC. He achieved biochemical remission with normalization of serum calcium and parathyroid hormone levels. At follow-up, there was no biochemical or imaging evidence of recurrence or metastasis. Genetic analysis revealed heterozygous germline deletion of CDC73. An extensive literature search on PC was conducted, with an emphasis on the pediatric population. Thirteen cases of pediatric PC were identified. The median age of presentation was 13 years; there was no sex predilection. All cases were symptomatic; 31% had a visible neck mass. The median serum calcium and intact parathyroid hormone levels were 14.3 mg/dL and 2000 pg/mL, respectively. All patients underwent surgical excision, with 27% showing metastatic relapse. Our findings indicate that the preoperative features that could point toward a diagnosis of PC in a child with PHPT are a tumor size of >3 cm, thyroid infiltration on imaging, and severe hypercalcemia at presentation. [ABSTRACT FROM AUTHOR]

The article describes two clinical cases of severe primary hyperparathyroidism (PHPT) caused by parathyroid carcinoma in young female patients who underwent molecular genetic testing to rule out the hereditary forms of PHPT. In both patients, heterozygous germline nonsense mutations of tumor suppressor gene CDC73 encoding parafibromin (p.R91X and p.Q166X) were identified using next-generation sequencing with Ion Torrent Personal Genome Machine (Thermo Fisher Scientific — Life Technologies, USA). It is the first description of CDC73 mutations in Russia, one of the mutations is described for the first time in the world. Identification of germline mutations in the CDC73 gene in patients with PHPT necessitates regular lifelong screening for other manifestations of hyperparathyroidism-jaw tumor syndrome (HPT-JT), PHPT recurrence due to parathyroid carcinoma as well, and identification of mutation carriers among first-degree relatives.

Background: Hereditary primary hyperparathyroidism (PHPT) accounts for 5-10% of all PHPT cases, necessitating genetic testing for diagnosis and management. Among these, hyperparathyroidism-jaw tumor syndrome (HPT-JT) is an autosomal dominant disorder caused by CDC73 mutations with variable clinical presentations and incomplete symptoms., Case Summary: The proband, diagnosed with PHPT, underwent parathyroidectomy at the age of 41 with pathological examination of parathyroid carcinoma (PC). Hereditary PHPT was initially suspected due to the early-onset PHPT and family history. Genetic testing identified a heterozygous CDC73 mutation, NM_024529.4: c. 687_688delAG (p. Arg229Serfs*37). Even in the absence of jaw tumors, the diagnosis of HPT-JT was confirmed based on the discovery of renal cysts. A secondary thyroidectomy was performed to reduce the risk of recurrence., Conclusion: Genetic testing is strongly recommended in cases of early-onset PHPT, family history, jaw tumors, renal and uterine involvement, atypical parathyroid tumors, and PC. This testing provides valuable information for personalized management, and counseling is available for affected families., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Gu, Ye, Shu, Chang, Xie, Li, Zhu, Liu and He.)

Parathyroid carcinoma (PC) may occur as part of a complex hereditary syndrome or an isolated (i.e., non-syndromic) non-hereditary (i.e., sporadic) endocrinopathy. Studies of hereditary and syndromic forms of PC, which include the hyperparathyroidism-jaw tumor syndrome (HPT-JT), multiple endocrine neoplasia types 1 and 2 (MEN1 and MEN2), and familial isolated primary hyperparathyroidism (FIHP), have revealed some genetic mechanisms underlying PC. Thus, cell division cycle 73 ( CDC73) germline mutations cause HPT-JT, and CDC73 mutations occur in 70% of sporadic PC, but in only ∼2% of parathyroid adenomas. Moreover, CDC73 germline mutations occur in 20%-40% of patients with sporadic PC and may reveal unrecognized HPT-JT. This indicates that CDC73 mutations are major driver mutations in the etiology of PCs. However, there is no genotype-phenotype correlation and some CDC73 mutations (e.g., c.679_680insAG) have been reported in patients with sporadic PC, HPT-JT, or FIHP. Other genes involved in sporadic PC include germline MEN1 and rearranged during transfection ( RET) mutations and somatic alterations of the retinoblastoma 1 ( RB1) and tumor protein P53 ( TP53) genes, as well as epigenetic modifications including DNA methylation and histone modifications, and microRNA misregulation. This review summarizes the genetics and epigenetics of the familial syndromic and non-syndromic (sporadic) forms of PC. [ABSTRACT FROM AUTHOR]

Hyperparathyroidism-jaw tumor (HPT-JT) is an autosomal dominant disorder responsible for benign and/or malignant tumors. Affected women often present life-threatening menorrhagia that leads to the identification of uterine tumors, and experience miscarriages and infertility. Overall though, fewer data concerning gynecological pathologies related to HPT-JT syndrome are available. We report the case of a 32-year-old woman with HPT-JT syndrome, referred for recurrent vaginal bleeding, with a history of repeated endometrial polyps and infertility. We also review the literature that explores medical options for these women. [ABSTRACT FROM AUTHOR]

Between 2% and 10% of patients with primary hyperparathyroidism (pHPT) are diagnosed with hereditary forms of primary hyperparathyroidism (hpHPT). They are more prevalent in younger patients before the age of 40 years, in patients with persistence or recurrence of pHPT and pHPT patients with multi-glandular disease (MGD). The various forms of hpHPT diseases can be classified into four syndromes, i.e., hpHPT associated with diseases of other organ systems, and four diseases that are confined to the parathyroid glands. Approximately 40% of patients with hpHPT suffer from multiple endocrine neoplasia type 1 (MEN-1) or show germline mutations of the MEN‑1 gene. Currently, germline mutations that lead to a specific diagnosis in patients with hpHPT have currently been described in 13 different genes, which enables a clear diagnosis of the disease; however, a clear genotype-phenotype correlation does not exist, even though the complete loss of a coded protein (e.g. due to frame-shift mutations in the calcium sensing receptor, CASR) often leads to more severe clinical consequences than merely a reduced function of the protein (e.g. due to point mutation). As the various hpHPT diseases require different treatment approaches, which do not correspond to that of sporadic pHPT, a clear definition of the specific form of hpHPT must always be strived for. Therefore, before surgery of a pHPT with clinical, imaging or biochemical suspicion of hpHPT, genetic proof or exclusion of hpHPT is necessary. The differentiated treatment approach for hpHTP can only be defined by taking the clinical and diagnostic results of all the abovenamed findings into account., (© 2023. The Author(s), under exclusive licence to Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

Primary hyperparathyroidism is a heterogeneous clinical entity. In the clinical setting, the diagnosis and management of familial isolated hyperparathyroidism (FIHP) and other familial hyperparathyroidism (FHPT) forms continue to rely on clinical, laboratory, and histological findings, with careful examination of the family. In this article, we report a case series of FIHP in a four-generation Greek family, with no identifiable gene mutations. Clinical approach and long-term follow-up are discussed and a narrative review of the genetic basis of this entity has been performed. [ABSTRACT FROM AUTHOR]

Objective: To describe the clinical management of menorrhagia in a woman with hyperparathyroidism–jaw tumor syndrome (HPT-JT). Design: Case report. Setting: Large translation research hospital. Patient(s): A 26-year-old nulligravid woman with familial HPT-JT presented with life-long menorrhagia resistant to progesterone intrauterine device (IUD) therapy and a desire for fertility. Intervention(s): Aromatase inhibitor therapy. Main Outcome Measure(s): Clinical response to therapy and pregnancy. Result(s): Imaging demonstrated an enlarged endometrial lining and thickening of the junctional zone. At operative hysteroscopy, multiple atypical endometrial polyp-like lesions filled the entire uterine cavity and were removed. Histologic evaluation demonstrated the lesions to be adenomyomas with an abundance of aromatase expression. Postoperative treatment included an aromatase inhibitor. The patient''s menorrhagia, which had previously been resistant to progesterone IUD therapy, resolved with the aromatase inhibitor. After 10 months of this treatment, the aromatase inhibitor was discontinued and a repeated hysteroscopy revealed a markedly improved uterine cavity. The patient subsequently became pregnant on her first natural cycle and delivered a healthy term infant. Conclusion(s): Aromatase inhibitors may represent a novel treatment for benign uterine pathology in HPT-JT. [Copyright &y& Elsevier]

Hyperparathyroidism-jaw tumor syndrome (HPT-JT) is an autosomal dominant disease characterized by the occurrences of parathyroid tumors and ossifying fibroma of maxilla/mandible. It is caused by mutations in CDC73 gene and mutation carriers are at increased risk of parathyroid carcinoma. Hyperparathyroidism could be the sole manifestation. We reported two Chinese patients having parathyroid neoplasm with equivocal malignant potential and parathyroid carcinoma respectively with both germline and somatic CDC73 mutations detected. Both of them presented with severe hypercalcemia and primary hyperparathyroidism with no other HPT-JT associated tumors and negative family history. We identified one novel germline mutation CDC73 NM_024529.4: c.1475G > A; NP_078805.3: p.Trp492X and one novel somatic mutation CDC73 NM_024529.4: c.142G > T; NP_078805.3: p.Glu48X. The other germline mutation CDC73 NM_024529.4: c.226C > T; NP_078805.3: p.Arg76X and somatic mutation CDC73 NM_024529.4: c.85delG; NP_078805.3: p.Glu29SerfsX8 were previously reported. This is the first report of CDC73 mutations in the Chinese population. Genetic analysis is reliable to confirm the underlying hereditary basis of hyperparathyroidism. By identification of mutations, the patient and the family members could benefit from regular surveillance for early detection of tumors. [ABSTRACT FROM AUTHOR]

Parafibromin is the 531-amino-acid protein product encoded by HRPT2, a putative tumor suppressor gene recently implicated in the autosomal dominant hyperparathyroidism-jaw tumor familial cancer syndrome, sporadic parathyroid cancer, and a minority of families with isolated hyperparathyroidism. Parafibromin contains no identified functional domains but bears sequence homology to Cdc73p, a budding yeast protein component of the RNA polymerase II-associated Paf1 complex. This study addressed the expression and functional properties of human parafibromin. A survey of human and mouse tissues analysed with polyclonal antibodies to parafibromin showed specific immunoreactivity in adrenal and parathyroid glands, kidney, heart, and skeletal muscle. Subcellular fractionation and laser confocal microscopy of normal human parathyroid gland demonstrated expression of parafibromin in both the cytoplasmic and nuclear compartments. Parafibromin was expressed in four parathyroid adenomas but was absent from two parathyroid carcinomas. Transient overexpression of wild-type parafibromin, but not its Leu64Pro missense mutant implicated in parathyroid cancer and familial isolated hyperparathyroidism, inhibited cell proliferation, and blocked expression of cyclin D1, a key cell cycle regulator previously implicated in parathyroid neoplasia. These results demonstrate that human parafibromin is a nucleocytoplasmic protein with functions consistent with its postulated role as a tumor suppressor protein.Oncogene (2005) 24, 1272-1276. doi:10.1038/sj.onc.1208274 Published online 6 December 2004 [ABSTRACT FROM AUTHOR]