Inheritance of familial hypercholesterolemia:

**Core Concept**
Familial hypercholesterolemia (FH) is a genetic disorder characterized by elevated levels of low-density lipoprotein (LDL) cholesterol due to mutations in the LDL receptor gene. This autosomal dominant disorder leads to premature atherosclerotic cardiovascular disease.

**Why the Correct Answer is Right**
The pathogenesis of FH is attributed to mutations in the LDL receptor gene, which encodes for a protein responsible for removing LDL cholesterol from the bloodstream. The most common mutation is a deletion of exon 8, leading to a nonfunctional LDL receptor. This results in impaired clearance of LDL cholesterol, causing its accumulation in the blood. The presence of a mutation in one allele is sufficient to cause the disease, as the remaining allele can still produce functional LDL receptors.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because familial hypercholesterolemia is not inherited in an autosomal recessive pattern. The presence of a single mutated allele is sufficient to cause the disease.
**Option B:** This option is incorrect because familial dysbetalipoproteinemia is a different genetic disorder characterized by the accumulation of intermediate-density lipoprotein (IDL) and very-low-density lipoprotein (VLDL) cholesterol.
**Option C:** This option is incorrect because familial combined hyperlipidemia is a genetic disorder characterized by elevated levels of multiple lipoproteins, including LDL, VLDL, and triglycerides.

**Clinical Pearl / High-Yield Fact**
Familial hypercholesterolemia is often diagnosed in individuals with a family history of premature cardiovascular disease, particularly in first-degree relatives. Early identification and treatment with statins and other lipid-lowering therapies can significantly reduce the risk of cardiovascular events.

**Correct Answer:** A. Autosomal dominant