Infantile McCune-Albright syndrome.

McCune-Albright syndrome is a rare disorder caused by an activating mutation of the alpha subunit of the Gs protein and is characterized by multiple hormonal abnormalities, fibrous dysplasia of bone, and cutaneous pigmentation. We report a 10-week-old infant with McCune-Albright syndrome. He presented with failure to thrive, cardiorespiratory distress, and pigmented macules on his face, trunk, and limbs. Following the clinical diagnosis of McCune-Albright syndrome, he was subsequently shown to have hypercortisolism and hyperthyroidism.