Albright's hereditary osteodystrophy phenotype is characteristic of:

• A. PHP Type 1A
• B. PHP Type 1B
• C. PPHP
• D. None of the above

Answer: (A)

Albright's hereditary osteodystrophy describes the skeletal changes you see in pseudohypoparathyroidism-related disorders, notably the brachydactyly with short metacarpals, round face, subcutaneous ossifications, and short stature. In pseudohypoparathyroidism type 1A, a maternal GNAS gene defect causes resistance to parathyroid hormone (and often other hormones) in target tissues, so you get both the AHO skeletal phenotype and multihormone resistance, including PTH. If the same GNAS mutation is inherited from the father, the imprinting pattern means the kidney and other tissues don’t show PTH resistance, but the patient still has AHO features—this is pseudopseudohypoparathyroidism. PHP-1B tends to show PTH resistance due to imprinting defects but usually lacks the classic AHO skeletal phenotype. So the Albright’s hereditary osteodystrophy appearance is most characteristically tied to pseudohypoparathyroidism type 1A, where the AHO features accompany hormone resistance driven by maternal GNAS mutation. If AHO is present without hormone resistance, PPHP fits, but the combination of AHO with hormone resistance points to PHP type 1A.