Question

A 10-year-old patient has high total cholesterol, tendon xanthomas, and a family history of similar findings. Triglyceride levels are normal. What type of familial dyslipidemia is most likely?

• A. Type I
• B. Type IIa
• C. Type IIb
• D. Type II

Hint:

Familial hypercholesterolemia with tendon xanthomas and normal triglycerides = Type IIa.

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
The patient is a child with isolated hypercholesterolemia (normal TG) and pathognomonic physical signs (tendon xanthomas).
This indicates a primary defect in Low-Density Lipoprotein (LDL) clearance, characteristic of Familial Hypercholesterolemia.
Step 2: Detailed Explanation:

Fredrickson Classification of Dyslipidemias: Lipidemias are categorized based on which lipoprotein is elevated.

Type IIa (Familial Hypercholesterolemia): This is an autosomal dominant condition characterized by an elevation in LDL (Low-Density Lipoprotein).

Pathogenesis: Most commonly due to a mutation in the LDL receptor gene, leading to decreased clearance of LDL from the blood.

Biochemical Profile: Very high total cholesterol (and LDL-C), but significantly, the triglyceride levels are normal.

Clinical Findings: Tendon xanthomas (specifically in the Achilles tendon or hand extensors) are the hallmark. Early-onset coronary artery disease is a significant risk.


Comparison with other types:

Type IIb: Elevation of both LDL and VLDL; therefore, both cholesterol and triglycerides are high.

Type I: High chylomicrons and extreme triglycerides; presents with eruptive xanthomas and pancreatitis.

Type III: High IDL (Dysbetalipoproteinemia); presents with palmar xanthomas.


Conclusion: Given the isolated high cholesterol and tendon xanthomas in a child, Type IIa is the definitive classification.

Step 3: Final Answer:
Type IIa familial hypercholesterolemia is the correct classification for isolated high LDL with tendon xanthomas.