Pseudohypoparathyroidism (PGP) is a rare hereditary disease characterized by clinical and laboratory signs of hypoparathyroidism against the background of an increased level of parathyroid hormone (PTH) in the blood. The prevalence of GWP has been studied in individual countries and is – 1 : 100000 – 1 : 295000. In 1942, F. Albright et al. we described a group of patients with characteristic features of the phenotype (obesity, growth retardation, moon-shaped face, subcutaneous calcifications, brachydactyly, mental retardation) against the background of a violation of phosphorus-calcium metabolism-hypocalcemia, hyperphosphatemia. The cause of PGP is the resistance of peripheral tissues to PTH, as a result of a violation of the mechanism of intracellular signal transmission from the activated receptor to the cell nucleus, usually due to pathology of the α-subunit of the G-protein (Gas) or other disorders of post-receptor signal transmission. The genetic basis of type 1a PGP is an inactivating mutation in the GNAS gene of the maternal allele. The consequence of this is the formation of a phenotype combined in the concept of hereditary Albright osteodystrophy (LEO), which develops with any inactivating mutation in the GNAS gene on both the maternal and paternal allele. This article describes a rare clinical case of a hereditary disease of pseudohypoparatheriosis type 1a (Albright's disease) in a girl.