For example, pseudohypoparathyroidism type 1A (PHP1A) and pseudopseudohypoparathyroidism (PPHP) are two dominant genetic diseases caused by rare loss-of-function mutations in the GNAS (Guanine Nucleotide Binding Protein, Alpha Stimulating Activity) gene, which encodes the α-subunit of the stimulatory G protein (Gsα). This evidence concerns the gene GNAS and pseudohypoparathyroidism type 1A.