MEN1 gene analysis in patients with primary hyperparathyroidism: 10-year experience of a single institution for thyroid and parathyroid care in Japan

A case of Turner's syndrome with Graves' disease and primary hyperparathyroidism

We report a 21-year-old woman with Turner's syndrome, Graves' disease and primary hyperparathyroidism. At 12 years of age, she was of short stature, and was diagnosed with Turner's syndrome and treated with growth hormone. At the age of 17 years, she was diagnosed with Graves' disease. On treatment with methimazole, her laboratory findings normalized. At the age of 20 years, her serum calcium and intact parathyroid hormone levels were high. The upper left parathyroid gland showed swelling and was resected, and adenoma was diagnosed pathologically. Then, primary hyperparathyroidism induced by the adenoma was diagnosed. After the parathyroidectomy, the patient's serum calcium and intact parathyroid hormone levels normalized. Is likely that Turner's syndrome and Graves' disease were not associated with primary hyperparathyroidism. Multiple endocrine neoplasia type 1 was unlikely considering the clinical, laboratory, ultrasonographic, and scintigraphic findings.

A practice guideline from the American College of Medical Genetics and Genomics and the National Society of Genetic Counselors: referral indications for cancer predisposition assessment

DISCLAIMER

The practice guidelines of the American College of Medical Genetics and Genomics (ACMG) and the National Society of Genetic Counselors (NSGC) are developed by members of the ACMG and NSGC to assist medical geneticists, genetic counselors, and other health-care providers in making decisions about appropriate management of genetic concerns, including access to and/or delivery of services. Each practice guideline focuses on a clinical or practice-based issue and is the result of a review and analysis of current professional literature believed to be reliable. As such, information and recommendations within the ACMG and NSGC joint practice guidelines reflect the current scientific and clinical knowledge at the time of publication, are current only as of their publication date, and are subject to change without notice as advances emerge. In addition, variations in practice, which take into account the needs of the individual patient and the resources and limitations unique to the institution or type of practice, may warrant approaches, treatments, and/or procedures that differ from the recommendations outlined in this guideline. Therefore, these recommendations should not be construed as dictating an exclusive course of management, nor does the use of such recommendations guarantee a particular outcome. Genetic counseling practice guidelines are never intended to displace a health-care provider's best medical judgment based on the clinical circumstances of a particular patient or patient population. Practice guidelines are published by the ACMG or the NSGC for educational and informational purposes only, and neither the ACMG nor the NSGC "approve" or "endorse" any specific methods, practices, or sources of information.Cancer genetic consultation is an important aspect of the care of individuals at increased risk of a hereditary cancer syndrome. Yet several patient, clinician, and system-level barriers hinder identification of individuals appropriate for cancer genetics referral. Thus, the purpose of this practice guideline is to present a single set of comprehensive personal and family history criteria to facilitate identification and maximize appropriate referral of at-risk individuals for cancer genetic consultation. To develop this guideline, a literature search for hereditary cancer susceptibility syndromes was conducted using PubMed. In addition, GeneReviews and the National Comprehensive Cancer Network guidelines were reviewed when applicable. When conflicting guidelines were identified, the evidence was ranked as follows: position papers from national and professional organizations ranked highest, followed by consortium guidelines, and then peer-reviewed publications from single institutions. The criteria for cancer genetic consultation referral are provided in two formats: (i) tables that list the tumor type along with the criteria that, if met, would warrant a referral for a cancer genetic consultation and (ii) an alphabetical list of the syndromes, including a brief summary of each and the rationale for the referral criteria that were selected. Consider referral for a cancer genetic consultation if your patient or any of their first-degree relatives meet any of these referral criteria.

Multiple endocrine neoplasia type 1 in Japan: establishment and analysis of a multicentre database

OBJECTIVE

Multiple endocrine neoplasia type 1 (MEN1) is less well recognized in Asian countries, including Japan, than in the West. The clinical features and optimal management of MEN1 have yet to be clarified in Japan. The aim of this study was to clarify the clinical features of Japanese patients with MEN1.

DESIGN/PATIENTS

We established a MEN study group designated the 'MEN Consortium of Japan' in 2008, and asked physicians and surgeons to provide clinical and genetic information on patients they had treated. Of 680 registered patients, 560 were analysed.

MEASUREMENTS

Clinical and genetic features of Japanese patients with MEN1 were examined.

RESULTS

Primary hyperparathyroidism, gastroenteropancreatic neuroendocrine tumours (GEPNET), and pituitary tumours were seen in 94·4%, 58·6% and 49·6% of patients, respectively. The prevalence of insulinoma was higher in the Japanese than in the West (22%vs 10%). In addition, 37% of patients with thymic carcinoids were women, while most were men in western countries. The MEN1 mutation positive rate was 91·7% in familial cases and only 49·3% in sporadic cases. Eight novel mutations were identified. Despite the availability of genetic testing for MEN1, the application of genetic testing, especially presymptomatic diagnosis for at-risk family members appeared to be insufficient.

CONCLUSIONS

We established the first extensive database for Asian patients with MEN1. Although the clinical features of Japanese patients were similar to those in western countries, there were several characteristic differences between them.

A novel splice site mutation of the MEN1 gene identified in a patient with primary hyperparathyroidism

Heterozygous germline mutation of the tumor suppressor gene MEN1 is responsible for multiple endocrine neoplasia type 1 (MEN1), a familial cancer syndrome characterized by pituitary, parathyroid and enteropancreatic tumors. Various mutations have been identified throughout the entire gene region in patients with MEN1 and its incomplete forms often manifested as familial isolated hyperparathyroidism and apparently sporadic parathyroid tumor. Mutation analysis of the MEN1 gene is a powerful tool for the early diagnosis of MEN1; however, the clinical significance of the identified mutations is not always obvious. In this study, a previously unreported missense MEN1 mutation, c.824G>T was identified in a patient with primary hyperparathyroidism and evaluated for its pathogenicity. This mutation was predicted to generate a putative missense menin protein, R275M. A stability test of the menin protein demonstrated that the stability of R275M mutant was reduced only slightly as compared with wild type menin, and therefore could not preclude the possibility that it was a rare benign polymorphism. However, further analysis of leukocyte mRNA and minigene experiments indicated that the mutant c.824G>T allele gives rise to abnormally spliced menin mRNA, and thereby confirmed that c.824G>T mutation is causative for MEN1. Thus, leukocyte mRNA analysis has been demonstrated useful to identify a splicing mutation of the MEN1 gene.

Primary hyperparathyroidism: an update

PURPOSE OF REVIEW

Primary hyperparathyroidism (PHPT) is a constantly evolving disease. As more evidence on the cardiovascular and neuropsychiatric manifestations of apparently asymptomatic disease accumulates, and since medical therapeutic options and surgical indications are being further investigated, it is important to review this disease entity to gain a fresh, updated perspective on the current disease phenotype and treatment approach.

RECENT FINDINGS

The pathogenesis of PHPT has not been completely elucidated yet, but some potential culprits, such as gene mutations, growth factors, calcium sensing receptor antibodies, and chronic vitamin D deficiency are being identified. There is increasing evidence that even mild, asymptomatic PHPT is associated with some aspects of cardiovascular and neuropsychiatric dysfunction, but the clinical significance as well as the reversibility with parathyroidectomy of these abnormalities remain to be determined. Medical therapies such as bisphosphonates and calcimimetics are showing some promise in the treatment of PHPT, although surgery remains the only curative intervention. The indications for surgical intervention in patients with asymptomatic PHPT have been recently revised.

SUMMARY

Parathyroidectomy is the treatment of choice for patients with symptomatic PHPT and patients with asymptomatic PHPT who fulfill certain age, bone density, serum calcium, and creatinine criteria. Further research is needed to determine whether patients with prominent cardiovascular and neuropsychiatric manifestations would benefit from such intervention.

Primary hyperparathyroidism in patients with multiple endocrine neoplasia type 1

Primary hyperparathyroidism may occur as a part of an inherited syndrome in a combination with pancreatic endocrine tumours and/or pituitary adenoma, which is classified as Multiple Endocrine Neoplasia type 1 (MEN-1). This syndrome is caused by a germline mutation in MEN-1 gene encoding a tumour-suppressor protein, menin. Primary hyperparathyroidism is the most frequent clinical presentation of MEN-1, which usually appears in the second decade of life as an asymptomatic hypercalcemia and progresses through the next decades. The most frequent clinical presentation of MEN-1-associated primary hyperparathyroidism is bone demineralisation and recurrent kidney stones rarely followed by chronic kidney disease. The aim of this paper is to present the pathomechanism, screening procedures, diagnosis, and management of primary hyperparathyroidism in the MEN-1 syndrome. It also summarises the recent advances in the pharmacological therapy with a new group of drugs-calcimimetics.