McCUNE ALBRIGHT SYNDROME:

McCune–Albright Syndrome (MAS), is a metabolic disorder resulting from the reduced sensitivity of target tissues to parathyroid hormone and other hormones.  MAS is characterized by polyostotic fibrous dysplasia, pigmented patches of skin and endocrine abnormalities including precocious puberty, pituitary gigantism and Cushing syndrome.

MAS has been found to be a result of mutations in the gene encoding the alpha subunit of the adenylate cyclase stimulatory G protein (GNAS) located at 20q13.2. To date all published studies report one of two mutations, an Arg201Cys or Arg201His, as being responsible for McCune-Albright Syndrome. These autosomal dominant McCune-Albright mutations are considered to be embryonically lethal. MAS patients are a result of tissue-specific mosaicism, with GNAS gene mutations present only in the affected tissues. The mosaic nature of the syndrome demands a highly sensitive site-specific PCR technique.  The testing can detect subpoplations of cells in the blood or affected tissues, but will not detect any other mutation than those targeted.

• Patients with polyostotic fibrous dysplasia.

• Patients with pigmented or Cafe' au lait spots on the skin.

• Patients with multiple endocrine defects.

• Detection of an Arg201Cys or Arg201His mutation by site-specific PCR, restriction enzyme digestion and DNA sequencing.

• Preferred sample- biopsy tissue from the affected site (ie., bone lesion or endocrine tissues) transported in media or physiologic saline. 
  
  Important Note: A skin biopsy from a Café au lait spot has a mutation detection rate lower than blood; therefore this is the least preferable specimen for testing.
  
  
• Alternate sample-
  • Blood (2 tubes 3-5 mL EDTA purple top) may be submitted when biopsy collection is impractical. It must be realized that the likelihood of detecting a mutation is somewhat reduced in a blood sample. However, for most patients blood is the easiest specimen to obtain.

TURNAROUND TIME:     3 weeks

CPT CODES: