History:

A 30 year old man feels crushing substernal chest pain one morning. After a couple of hours at work, the pain persists. He has diaphoresis and dizziness. He goes to a local ER. An EKG shows T wave inversion and ST segment elevation. His brother had a similar experience a year ago.

The major pathologic findings pictured in the images include severe atherosclerosis involving the aorta and coronary arteries. There is an acute myocardial infarction

Questions:

1. What laboratory test would be helpful to confirm your diagnosis?

CK-MB or troponin I.

2. What factors suggest a genetic basis for this illness?

Young age at onset; affected sibling.

3. What disease is suggested by these findings? What is the incidence

Familial hypercholesterolemia. The incidence is 1:500 for the heterozygous state

4. What labortory test would confirm this?

Serum cholesterol. This patient's total serum cholesterol is 404 mg/dL.

5. What is the pathophysiology for this condition?

There is a mutation in the LDL receptor. LDL cholesterol accumulates and is oxidized, which is taken up into arterial walls.

6. Is this disease recessive or dominant?

Neither. A 50% loss of LDL receptors still results in elevations of cholesterol, about 2 to 3 times normal, while a complete loss results in 5 to 6-fold elevations in cholesterol.