Which syndrome involves a mosaic G-protein signaling mutation leading to precocious puberty?

McCune-Albright syndrome is characterized by a mutation in the GNAS gene, which encodes a G-protein that plays a crucial role in signaling pathways related to hormone production. This mosaic mutation leads to dysregulation of the endocrine system, particularly affecting the ovaries and adrenal glands. As a result, individuals with this syndrome often experience precocious puberty due to increased levels of estrogen or other sex hormones.

In McCune-Albright syndrome, the combination of endocrine manifestations can include not only early onset of puberty but also fibrous dysplasia of bone and café-au-lait skin pigmentation. The presence of a mosaic mutation means that only a subset of cells carries the mutation, leading to a variety of symptoms that can vary widely among individuals.

The other options do not involve the specific mechanism of a G-protein signaling mutation leading to precocious puberty. Androgen insensitivity syndrome primarily affects the development of male sexual characteristics. Turner syndrome involves the absence of an X chromosome in females and is associated with various developmental issues, including short stature and lack of ovarian function, but not precocious puberty. Cushing's syndrome is characterized by excessive cortisol production and does not typically result in early onset of puberty. Therefore, McCune-Albright syndrome is