aINHA University Hospital, Incheon, Democratic Peoples Republic of Korea; bSamsung Medical Center, Seoul, Democratic Peoples Republic of Korea
Pseudohypoparathyroidism (PHP) is a disease of rare frequency. There are five subtypes with each having different phenotypes and blood laboratory test results, which depend on gene mutation and hereditary styles. Among them, the most common type is PHP Ia which inherits maternal gene mutation and expresses Albrights hereditary osteodystrophy (AHO) appearance, hypocalcemia, hyperphosphatemia and serum parathyroid hormone elevation. Another type, pseudo-pseudohypoparathyroidism (PPHP), inherits the same paternal gene mutation and expresses AHO appearance, except abnormal blood test results. We report a novel GNAS gene mutation found cases of AHO phenotype in a son with PHP Ia and his mother with PPHP.