McCune-Albright Syndrome


McCune-Albright Syndrome is caused by a mutation in the GNAS1 gene, which codes for a Gs protein subunit. This mutation is only survivable with mosaicism, as it is lethal if the mutation affects all cells. Clinical findings of McCune-Albright are unilateral cafe-au-lait spots, polyostotic fibrous dysplasia, pathologic bone fractures, lytic holepunch lesions in bone, and endocrinopathies--such as precocious puberty.