Endocrine Abstracts

Introduction: Pseudohypoparathyroidism (PHP) is a rare genetic disease characterized by renal resistance to parathyroid hormone (PTH), presenting with hypocalcemia, hyperphosphatemia and elevated PTH levels. We describe a PHP patient who presented with clinically significant hypercalcemia.Case description: A 46-year-old woman with a prior history of hypocalcemia presented to the emergency department with new-onset hypercalcemia, renal failure and anemia....

Pseudohypoparathyroidism type 1B (PHP-1B) is a rare, familial or sporadic, imprinting disorder due to the epigenetic dysregulation of the GNAS locus, whose main product is the α subunit of the stimulatory G protein (Gsα). Sporadic PHP-1B cases (spor-PHP-1B) display broad methylation abnormalities at multiple GNAS DMRs, but the underlying molecular mechanism is still unknown.Classically, PHP-1B patients show PTH and TSH resistance, but, in the p...

The term pseudohypoparathyroidism (PHP) defines a heterogeneous group of rare, related and deeply impairing metabolic diseases due to end-organ resistance to the actions of PTH, associated to molecular defects at the GNAS locus. Different subtypes of PHP have been described based on the existence of additional clinical features, such as resistance to other hormones acting via GPCRs and Albright’s hereditary osteodystrophy (AHO). Recently, the detection in a small subset o...

The impairment of the parathyroid hormone (PTH) signaling pathway determines a group of related and highly heterogeneous disorders associated or not with the Albright’s hereditary osteodystrophy (AHO) phenotype, classified as inactivating PTH/PTHrP signaling disorder (iPPSD). iPPSD features are rather difficult to be identified in some casesbecause manifestations are somewhat variable and some AHO characteristics are not specific to a specific disorder. Actually, besides...

Epi/genetic defects at the imprinted GNAS locus, that encodes the α subunit of the stimulatory G protein (Gsα), have been associated with a heterogeneous group of rare diseases, termed as Pseudohypoparathyroidism. Most GNAS-based disorders have the common feature of episodic de novo formation of heterotopic ossifications (HO) in subcutaneous tissues. The mosaic tissue distribution of HO suggests that pathogenesis involves an abnormal differentiation of precu...

Progressive osseous heteroplasia (POH) is a rare autosomal dominant disorder of mesenchymal differentiation characterized by progressive heterotopic ossification (HO) of dermis, skeletal muscle and deep connective tissues. Initially HO occurs during infancy as osteoma cutis, then extends progressively into deep connective tissues during childhood. Most cases of POH are caused by paternally inherited mutations of GNAS gene. Maternal mutations as well as epigentic defec...

Introduction: Primary bilateral macronodular adrenal hyperplasia (PBMAH) is a rare cause of Cushing’s syndrome (CS). Some familial forms have been associated to gene ARMC5 (Armadillo repeat-containing protein 5) inactivating mutations. This study aimed to evaluate the prevalence and the complications of ARMC5 mutations in our cohort of patients with bilateral adrenal incidentalomas (BAI).Methods: 72 patients, referred to our Center...

The clinical condition resulting from end-organ resistance to parathormone (rPTH), caused by (epi)genetic alterations of GNAS, was termed as Pseudohypoparathyroidism (PHP). The high phenotype heterogeneity, the existence of additional clinical features such as resistance to other hormones (TSH/GHRH/gonadotropins) and Albright’s hereditary osteodystrophy (AHO), led to the distinction of specific PHP subtypes.The purpose of the present work is to prov...

Background: Disorders caused by impairments in the parathyroid hormone (PTH) signaling pathway are historically classified under the term pseudohypoparathyroidism (PHP), that encompasses rare, related but highly heterogeneous diseases with demonstrated (epi)genetic causes. The actual classification is based on the presence or absence of specific clinical and biochemical signs together with an in vivo response to exogenous PTH and the results of an in vitro as...

Pseudohypoparathyroidism (PHP) and related disorders lead to a wide spectrum of abnormal physical characteristics, neurocognitive and endocrine abnormalities that share a common PTH/PTHrP signaling pathway. The clinical and molecular overlap of PHP and related disorders lead to difficulties in clinical and molecular diagnosis which prompt to the possibility of incorrect management of these patients. PHP (including all subtypes), pseudoPHP, acrodysostosis and progressive osseou...