GNAS and pseudopseudohypoparathyroidism: Pseudohypoparathyroidism (PHP) and pseudo‐pseudohypoparathyroidism (PPHP) are endocrine system diseases caused by genetic and/or epigenetic changes in the parathyroid hormone/parathyroid hormone‐related protein (PTH/PTHrP) signaling pathway involving the alpha subunit of the stimulatory G protein (Gsa) (Jüppner, 2021).