pseudohypoparathyroidism
Pronunciation: soo-doe-hahy-poh-par-uh-THAHY-roi-diz-uhm
Genetic disorder causing resistance to parathyroid hormone action, resulting in hypocalcemia despite elevated PTH levels.
Full Definition
Pseudohypoparathyroidism (PHP) is a rare genetic disorder characterized by resistance to parathyroid hormone (PTH) action in target tissues, particularly the kidneys and bones. Despite elevated or normal PTH levels, patients develop hypocalcemia, hyperphosphatemia, and often exhibit features of Albright hereditary osteodystrophy including short stature, brachydactyly, and intellectual disability. The condition is caused by mutations in genes encoding components of the cAMP signaling pathway, most commonly GNAS. Management includes calcium and vitamin D supplementation to maintain normal serum calcium levels.
Usage
Usage note: Distinguish carefully from hypoparathyroidism and pseudopseudohypoparathyroidism.
In Context
- "The combination of hypocalcemia, elevated PTH, and brachydactyly suggested pseudohypoparathyroidism type 1a." — Clinical assessment
- "Genetic testing confirmed GNAS mutation consistent with pseudohypoparathyroidism." — Laboratory report