Albright's hereditary osteodystrophy phenotype is associated with which form?

• A. PHP Type 1A
• B. PHP Type 1B
• C. PPHP
• D. All forms equally

Answer: (A)

Albright’s hereditary osteodystrophy describes the skeletal and subcutaneous changes seen with GNAS-related hormone resistance. This AHO phenotype is most characteristically linked to pseudohypoparathyroidism type Ia, where a mutation on the maternal GNAS allele causes resistance to PTH in multiple tissues along with the distinctive AHO features. Those features include short metacarpals with brachydactyly, a round face, short stature, and sometimes subcutaneous ossifications.

If the GNAS mutation is on the paternal allele, you can see the AHO phenotype without hormone resistance (pseudopseudohypoparathyroidism). Conversely, the other PHP type with primarily hormone resistance but minimal AHO features is less classically tied to the full AHO picture. So, the classic association of Albright’s phenotype is with pseudohypoparathyroidism type Ia.