|Café-au-lait skin pigmentation.
A) A typical lesion on the face, chest, and arm of a 5-year-old girl with McCune-Albright syndrome which demonstrates jagged "coast of Maine" borders, and the tendency for the lesions to both respect the midline and follow the developmental lines of Blaschko.
B) Typical lesions that are often found on the nape of the neck and crease of the buttocks are shown (arrows).
McCune–Albright syndrome, also known as Albright syndrome, is a complex genetic disorder affecting the bone, skin, and endocrine systems.
Signs and symptoms
McCune–Albright syndrome is suspected when one or more of the following features are present:
- Hyperfunctioning endocrine disease (gonadotropin independent precocious puberty, hyperthyroidism, growth hormone excess, neonatal Cushing syndrome)
- Fibrous dysplasia
- Café au lait macules
Patients may have one or many of these features, which may occur in any combination.
The clinical presentation varies greatly depending on the disease features. Patients with fibrous dysplasia may have bone fractures and deformities of the legs, arms and skull.
Cafe-au-lait skin macules tend to have characteristic features, including jagged "coast of Maine" borders, and location respecting the midline of the body.
Endocrine disease in McCune-Albright syndrome results from increased hormone production from glands regulated by the G protein system. This results in the so-called "autonomous production" of hormones, including thyroid hormone, cortisol, estrogen and growth hormone. Therefore, hyperthyroidism, Cushing syndrome, precocious puberty in women with premature thelarche (breast growth), premature menarche (beginning of menstrual function), increased speed of growth and growth hormone excess can ensue. Increased serum estrogen concentrations correlate with large ovarian cysts. Ovarian cysts appear and disappear with changing estrogen concentrations, causing menstrual bleeding when estrogen decreases.
McCune–Albright syndrome has different levels of severity. For example, one child with McCune–Albright syndrome may be entirely healthy, with no outward evidence of bone or endocrine problems, enter puberty at close to the normal age, and have no unusual skin pigmentation. Diagnosis may be made only after decades. In other cases, children are diagnosed in early infancy, show obvious bone disease, and obvious increased endocrine secretions from several glands.
Genetically, there is a postzygotic mutation (spontaneous mutation) of the gene GNAS1, on the long (q) arm of chromosome 20 at position 13.3, which is involved in G-protein signalling. This mutation, often a mosaicism, prevents downregulation of cAMP signalling.
The disease made headlines in December, 2005 when a Haitian teen affected with the disease, Marlie Casseus, underwent a 17-hour emergency surgical procedure to remove a 7 kg (16 pound) tumour-like growth of bone from her face. A series of operations at Holtz Children's Hospital in Miami, Florida restored the child's face to a more normal proportion.
- synd/1844 at Who Named It?
- McCune, Donovan J.; Bruch, Hilde (1937). "Progress in Pediatrics: Osteodystrophia Fibrosa". Archives of Pediatrics & Adolescent Medicine. 54 (4): 806. doi:10.1001/archpedi.1937.01980040110009.
- Albright F, Butler AM, Hampton AO, Smith P (1937). "Syndrome characterized by osteitis fibrosa disseminata, areas of pigmentation and endocrine dysfunction, with precocious puberty in females: report of five cases". N. Engl. J. Med. 216 (17): 727–746. doi:10.1056/NEJM193704292161701.
- Collins MT, Sarlis NJ, Merino MJ, et al. (September 2003). "Thyroid carcinoma in the McCune-Albright syndrome: contributory role of activating Gs alpha mutations". J. Clin. Endocrinol. Metab. 88 (9): 4413–7. PMID 12970318. doi:10.1210/jc.2002-021642.
- "Marlie Casseus". Archived from the original on 2007-05-29. Retrieved 2007-07-14.