Which statement best describes PPHP?

Which statement best describes PPHP?

• A. It presents with PTH resistance and hypocalcemia
• B. It lacks AHO phenotype
• C. It presents with AHO phenotype and PTH resistance
• D. It presents with AHO phenotype but no PTH resistance

Answer: (D)

PPHP, or pseudopseudohypoparathyroidism, is characterized by the Albright hereditary osteodystrophy (AHO) phenotype without resistance to parathyroid hormone. The skeletal features—such as brachydactyly, short stature, and other AHO changes—appear, but calcium and phosphate homeostasis function normally because target tissues respond to PTH. In other words, PTH signaling is intact, so there is no hypocalcemia or hyperphosphatemia, and PTH levels don’t need to compensate. This differs from pseudohypoparathyroidism, where AHO features can be present along with PTH resistance, causing low calcium, high phosphate, and elevated PTH due to end-organ unresponsiveness. It also differs from conditions that lack AHO features altogether. So the statement that best describes PPHP is that it presents with the AHO phenotype but no PTH resistance.

PPHP, or pseudopseudohypoparathyroidism, is characterized by the Albright hereditary osteodystrophy (AHO) phenotype without resistance to parathyroid hormone. The skeletal features—such as brachydactyly, short stature, and other AHO changes—appear, but calcium and phosphate homeostasis function normally because target tissues respond to PTH. In other words, PTH signaling is intact, so there is no hypocalcemia or hyperphosphatemia, and PTH levels don’t need to compensate.

This differs from pseudohypoparathyroidism, where AHO features can be present along with PTH resistance, causing low calcium, high phosphate, and elevated PTH due to end-organ unresponsiveness. It also differs from conditions that lack AHO features altogether.

So the statement that best describes PPHP is that it presents with the AHO phenotype but no PTH resistance.