MAS can be diagnosed if a patient has FD and at least one extraskeletal manifestation (café-au-lait skin hyperpigmentation, peripheral precocious puberty, thyroid lesions consistent with FD/MAS, growth hormone excess, neonatal hypercortisolism) or the absence of skeletal involvement but 2 extra-skeletal manifestations (6). Here, GH1 is linked to McCune-Albright syndrome.