**Core Concept**
Gs-alpha subunit is a crucial component of heterotrimeric G-proteins that play a pivotal role in signal transduction pathways. It is involved in the activation of various downstream effectors, including adenylyl cyclase, leading to the production of cyclic AMP (cAMP).

**Why the Correct Answer is Right**
Gs-alpha mutations can lead to an overactive G-protein, resulting in excessive stimulation of adenylyl cyclase. This causes a persistent increase in cAMP levels, which can activate protein kinase A (PKA) and lead to various downstream effects, including increased lipolysis and glycogenolysis. The specific clinical manifestation of a Gs-alpha mutation is McCune-Albright syndrome, characterized by café-au-lait skin spots, polyostotic fibrous dysplasia, and various endocrine abnormalities, such as precocious puberty and acromegaly.

**Why Each Wrong Option is Incorrect**
**Option A:** Mutations in the Gs-alpha subunit are not typically associated with familial hypercholesterolemia. This condition is primarily caused by mutations in the LDL receptor gene.
**Option B:** Gs-alpha mutations are not directly linked to the development of Parkinson's disease. This condition is primarily caused by mutations in the SNCA, PARK2, or DJ-1 genes.
**Option C:** While Gs-alpha mutations can lead to increased cAMP levels, they are not typically associated with hypoglycemia. This condition is more commonly caused by mutations in the glucagon-like peptide-1 (GLP-1) receptor or the glucose-dependent insulinotropic polypeptide (GIP) receptor.

**Clinical Pearl / High-Yield Fact**
Gs-alpha mutations can lead to a variety of clinical manifestations, including McCune-Albright syndrome, which is characterized by a triad of café-au-lait skin spots, polyostotic fibrous dysplasia, and various endocrine abnormalities.

**Correct Answer: C. McCune-Albright syndrome**