Genetics of parathyroids disorders: Overview.

Several familial forms of primary hyperparathyroidism (PHTP) have been discovered over the past 25 years, and molecular test for their risk assessment has been widely increasing. These syndromic and non-syndromic forms have received benefits from the identification of the responsible genes whose mutations account for the genetic susceptibility to develop parathyroid tumours as also other endocrine and nonendocrine tumours. In recent years, care options have been made available to patients and families with hereditary PHPT, and the process of systematically assessing the genetic risk has been becoming increasingly important. The aim of this review is to help health providers not frequently dealing with genetic testing use, introducing general concepts with regard to genetic diagnosis issues. The role and the practical usefulness of DNA-based diagnosis in patients affected by different forms of "congenital" PHPT is described, closely looking on why, when and how genetic testing should be performed in these subjects and their relatives. Moreover, this review will provide some practical suggestions and recommendations concerning on how to deal with a suspected or known case of familial PHPT.

Management of familial hyperparathyroidism syndromes: MEN1, MEN2, MEN4, HPT-Jaw tumour, Familial isolated hyperparathyroidism, FHH, and neonatal severe hyperparathyroidism.

While primary hyperparathyroidism (PHPT) generally represents a common endocrine disorder, being the more frequent cause of hypercalcemia in outpatients, familial forms of PHPT (FPHPT) account for no more than 2-5% of the overall PHPT. In the last decades, many technical progresses in both molecular and biochemical-radiological evaluation have been made, and substantial advancements in understanding these disorders have been reached. Differences both in the pathogenesis and clinical presentation exist among the various hyperparathyroid syndromic forms, and, since FPHPT is frequently associated to other endocrine, proliferative and/or functional disorders, as also non-endocrine tumours, with varying clinical spectrum of occurrence in each syndrome, its early clinically detection for appropriately preventing complications (i.e. kidney and bone disorders) is strictly advised. In this review, the clinical-biochemical features and diagnostic procedures of each FPHPT form will be summarized and a general overview on surgical and pharmacological approaches to FPHPT has been also considered.

Genetic aspects of the Paget's disease of bone: concerns on the introduction of DNA-based tests in the clinical practice. Advantages and disadvantages of its application.

BACKGROUND: A large amount of genetic studies have clearly demonstrated the existence of a genetic susceptibility to Paget's disease of bone (PDB). Although the disease is genetically heterogeneous, the SQSTM1/p62 gene, encoding a protein with a pathophysiological role in both osteoclast differentiation and activity, has been found worldwide to harbour germline mutations in most of the PDB patients from geographically distant populations originating from different areas of Europe, both in sporadic and familial cases. MATERIALS AND METHODS: Thus, SQSTM1/p62 gene mutations may confer an increased lifetime risk of developing PDB. RESULTS: Several different genotype-phenotype analyses have shown a high penetrance for such mutations. These results suggest the opportunity to perform genetic testing in affected individuals and then, after the identification of a SQSTM1/p62 gene germline mutation, in their relatives as a real and concrete strategy to increase the diagnostic sensitivity in most of the asymptomatic mutant carriers. However, it is of note to underlie that an incomplete penetrance for SQSTM1/p62 gene mutations has also been reported. CONCLUSIONS: In light of all these contradictory evidences, a review on whether, when and why apply the DNA test to those subjects, its interpretation and clinical application is necessary. In fact, a growing number of preventive care options are now available to affected patients and families and the process of systematically assessing risk is becoming increasingly important for both patients and physicians.