ESPE Abstracts

Background: Pseudohypoparathyroidism (PHP) is characterized by proximal tubular resistance to PTH and, in some disease variants, by Albright osteodystrophy. PHP is caused either by mutations in those regions of GNAS encoding Gsα (PHP1A and PseudoPHP) or by GNAS methylation defects (autosomal dominant (AD) and sporadic (spor) PHP1B). Phenotypic differences in fetal growth, post-natal growth and metabolism are observed in the different PHP types.<p cla...

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: Sporadic pseudohypoparathyroidism type Ib (spor-PHP-Ib) is caused by GNAS methylation alterations with loss of imprinting at the exon A/B differentially methylated region (DMR), without genetic deletions disrupting the STX16 ICR. These patients classically display hormone resistance limited to PTH and TSH with no Albright hereditary osteodistrophy (AHO).Objective and hypotheses: We describe two cases with the same imprinting methylat...

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...