McCune Albright syndrome and bilateral adrenal hyperplasia: the GNAS mutation may only be present in adrenal tissue.

Hormones (Athens, Greece)

PubMedID: 26188235

Angelousi A, Fencl F, Faucz FR, Malikova J, Sumnik Z, Lebl J, Stratakis CA. McCune Albright syndrome and bilateral adrenal hyperplasia: the GNAS mutation may only be present in adrenal tissue. Hormones (Athens). 2015;.
OBJECTIVE
Corticotropin (ACTH)-independent hypercortisolism due to bilateral adrenocortical hyperplasia (BAH) in infancy is an extremely rare condition that is often caused by McCune Albright syndrome (MAS). MAS is caused by an activating mutation of the GNAS gene which leads to increased cyclic (c) adenosine monophosphate (AMP) signaling. Most forms of BAH are linked to increased cAMP signaling. We report the case of an infant with MAS who had BAH.

METHODS
Genomic DNA fragments from blood and adrenal tissue encompassing regions (exons 8 and 9) with the hot spot activating missense GNAS mutations were amplified by classical bidirectional Sanger sequencing.

RESULTS
The infant was found to carry the most common GNAS mutation, in exon 8 (c.602G >A, p. R201H), only in her adrenocortical tissue, despite extensive skin and other findings.

CONCLUSIONS
We conclude that infants with MAS, despite absence of the GNAS activating mutation in blood, may still have significant clinical findings, including ACTH-independent hypercortisolism. Molecular confirmation of the diagnosis should be sought at the tissue level in these patients.