A young man presents to his physician’s office for a physical exam. He is concerned because his father died of a hea attack in his late 40’s. The physician finds that he has elevated serum cholesterol and LDL levels, but his VLDL and triglycerides are normal. Fuher investigation reveals an LDL receptor deficiency. This patient has which of the following types of hyperlipidemia?

**Core Concept**
The underlying principle being tested is the understanding of **hyperlipidemia** types, specifically those related to defects in **lipid metabolism** and **receptor function**. This involves knowledge of **lipoproteins**, such as **LDL (Low-Density Lipoprotein)**, and their role in **cholesterol transport**.

**Why the Correct Answer is Right**
The correct answer is related to a condition characterized by an **LDL receptor deficiency**, leading to elevated **LDL cholesterol** levels. This condition is known as **Familial Hypercholesterolemia (FH)**, where the deficiency of **LDL receptors** on the surface of **hepatocytes** impairs the clearance of **LDL** from the bloodstream, resulting in **hypercholesterolemia**.

**Why Each Wrong Option is Incorrect**
**Option A:** This would be incorrect because it typically involves elevated **VLDL** and **triglycerides**, not just **LDL**.
**Option B:** This is incorrect as it usually presents with elevated **triglycerides** and **VLDL**, and is not primarily due to an **LDL receptor deficiency**.
**Option C:** This option is incorrect because it is characterized by a different lipid profile and is not directly related to an **LDL receptor deficiency**.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that **Familial Hypercholesterolemia** significantly increases the risk of **premature coronary artery disease**, making early diagnosis and treatment crucial. The presence of **xanthomas** or **arcus senilis** in a young patient can be a clue to this condition.

**Correct Answer:** D. Familial Hypercholesterolemia.

✓ Correct Answer: B. Type IIa