| A heterogeneous group of endocrine disorders with characteristics of normal renal function and resistance to the action of parathyroid hormone (PTH), manifesting with hypocalcemia, hyperphosphatemia and elevated PTH levels and that includes the subtypes PHP type 1a (PHP-1a) , PHP type 1b (PHP-1b), PHP type 1c (PHP-1c), PHP type 2 (PHP-2) and pseudopseudohypoparathyroidism (PPHP). PHP-1a, PPHP, and PHP-1b are all due to molecular defects in the same locus of the GNAS (20q13.2-q13.3) gene coding the alpha sub-unit of the stimulatory G protein. PHP can be sporadic or inherited autosomal dominantly with parental imprinting. |
