ESPE Abstracts

Background: Patients affected with PHP1B are characterized by resistance to PTH which binds to the PTH receptor and activate the cAMP/Gsa signaling pathway. Gsa is encoded by GNAS, a locus subjected to genomic imprinting. PHP1B patients present with abnormal methylation at the maternal A/B promoter and, in some cases, at the other promoters (XLas, GNAS-AS1 and NESP55) of the GNAS locus, likely leading to a decreased express...

Background: Pseudohypoparathyroidism type 1A (PHP1A) and PseudoPHP are caused respectively by maternal and paternal mutations involving those GNAS exons that encode the alpha-subunit of the stimulatory G protein (Gsα). Common to different forms of PHP1B is a loss-of-methylation (LOM) at one or several maternal GNAS exons, which likely reduces Gsα expression in certain tissues. In most autosomal dominant PHP1B variants (AD-PHP1B), LOM is restricted t...

Background: Pseudohypoparathyroidism 1A, newly classified as inactivating PTH/PTHrP signaling disorder type 2 (iPPSD2), is defined by resistance to parathyroid hormone, short stature and early-onset obesity. Short stature is caused by skeletal dysplasia and additionally, in some cases, also by the coexistence of growth hormone deficiency, as other hormonal resistances might be present (e.g. thyroid-stimulating hormone, growth hormone releasing hormone (GHRH), ...

Background: Disorders related to an impairment in parathyroid hormone (PTH) signaling pathway are historically classified under the term pseudohypoparathyroidism (PHP), that now 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 an in vitro assay of Gs&#9...

Pseudohypoparathyroidism (PHP) and related disorders lead to a wide spectrum of abnormal physical characteristics, neurocognitive and endocrine abnormalities. PHP (including all subtypes), pseudoPHP, acrodysostosis and progressive osseous heteroplasia refer to heterogeneous disorders characterized by physical findings, differently associated in each subtype, including short bones, short stature, stocky build, subcutaneous ectopic ossifications, as well as laboratory abnormalit...