Table 2: New classification of Pseudohypoparathyroid disorders proposed by the European Pseudohypoparathyroidism Network [8].
| Inactivating PTH/PTHrp Signaling Disorders (iPPSD) | |
| New Nomenclature | Molecular defects and disease names |
| iPPSD1 | - Inactivating PTHR1 mutations - Blood strand & Eiken Chondrodysplasia |
| iPPSD2 | - Inactivating Gsα mutations - PHP 1a, PHP 1c, PPHP/AHO/POH |
| iPPSD3 | - Methylation changes at one or more GNAS DMRs - PHP1b |
| iPPSD4 | - PRKA1A mutations leading to reduced PKA activity - Acrodysostosis type 1 |
| iPPSD5 | - Activating PDE4D mutations - Acrodysostosis type 2 |
| iPPSD6 | - Activating PDE3A mutations - Autosomal dominant hypertension with brachydactyly |
| iPPSDx | - Unknown molecular defects |
| iPPSD n+1 | - New molecular defects |
PTHrp: Parathyroid Hormone-Related Protein; iPPSD: Inactivating Parathyroid Hormone/Parathyroid Hormone-Related Protein Signaling Disorder; PHP: Pseudohypoparathyroidism; PPHP: Pseudopseudohypoparathyroidism; AHO: Albrights Hereditary Osteodystrophy; POH: Progressive Osseous Heteroplasia; DMRs: Differentially Methylated Regions; PRKAR1A: Protein Kinase Camp-Dependent Type 1 Regulatory Subunit Alpha; PKA: Protein Kinase A; PDE4D: Phosphodiesterase 4D; PDE3A: Phosphodiesterase 3A.