Question

A patient with multiple tendon xanthomas is found to have a serum cholesterol level of 398 mg/dL and an LDL level of 220 mg/dL. What is the most likely defect?

• A. Lipoprotein lipase deficiency
• B. LDL receptor defect
• C. Defective Apo B-100
• D. PCSK9 gain-of-function mutation

Hint:

In cases of familial hypercholesterolemia, look for tendon xanthomas and significantly elevated LDL levels. The defect usually lies in the LDL receptor.

Answer 1

The Correct Option is B

This patient’s elevated cholesterol and LDL levels, combined with the presence of tendon xanthomas, suggest familial hypercholesterolemia, which is often due to an LDL receptor defect. This defect impairs the clearance of LDL from the bloodstream, resulting in elevated cholesterol levels.