McCune-Albright syndrome
| McCune-Albright syndrome | |
| ICD-10 | Q78.1 |
|---|---|
| ICD-9 | 756.54 |
| OMIM | 174800 |
| DiseasesDB | 7880 |
| MedlinePlus | 001217 |
| eMedicine | ped/1386 |
| MeSH | D005359 |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
McCune-Albright syndrome is a rare genetic disorder caused by an activating mutation of the GNAS gene resulting in various phenotypic presentations. MAS typically presents with the triad of polyostotic fibrous dysplasia, precocious puberty and café au lait spots in both genders. Other manifestations include hyperthyroidism, acromegaly and Cushing’s syndrome.[1]
Historical Perspective
McCune-Albright syndrome was first discovered by Donovan McCune and Fuller Albright, both physicians in 1937. [2]
Classification
McCune-Albright syndrome is caused by a missense mutation of the GNAS gene alpha subunit which becomes constitutively activated. This increases intracellular cAMP which activates downstream hormones resulting in multiple tissue types being affected and mosaicism presented in its patients. [1]
Pathophysiology
The pathogenesis of McCune-Albright syndrome is characterized by increased cAMP signaling in bone, skin and endocrine tissues. In bone osteoblasts differentiation results in fibrous dysplasia. In the skin there is stimulation of melanin production resulting in café au lait macules with irregular borders. In endocrine tissues increased cAMP results in increased production of hormones depending on which tissue is affected including the gonads, thyroid, parathyroid, pituitary and adrenal glands. [1]