Familial dysbetalipoproteinemia

Synonyms: Type III hyperlipoproteinemia; Deficient or defective apolipoprotein E

Definition
Familial dysbetalipoproteinemia is a disorder passed down through families in which there are high amounts of cholesterol and triglycerides in the blood.

Causes
A genetic defect causes this condition. The defect results in the build up of large lipoprotein particles that contain both cholesterol and triglycerides, a type of fat. The disease is linked to defects in the gene for apolipoprotein E in many cases.

Hypothyroidism, obesity, or diabetes can make the condition worse. Risk factors for familial dysbetalipoproteinemia include a family history of the disorder or coronary artery disease.

Symptoms
Symptoms may not be seen until age 20 or older.

Yellow deposits of fatty material in the skin called xanthomas may appear on the eyelids, palms of the hands, soles of the feet, or on the tendons of the knees and elbows.

Atherosclerosis develops. There may be early chest pain (angina) or decreased blood flow to specific parts of the body, causing transient ischemic attacks of the brain or peripheral artery disease.

Exams and Tests
Tests that may be done to diagnose this condition include:
 * Angiogram
 * Genetic testing for apolipoprotein E (apoE)
 * Heart stress test
 * Total cholesterol
 * Triglyceride level
 * Very low density lipoprotein (VLDL) test

Treatment
The goal of treatment is to control underlying conditions such as obesity, hypothyroidism, and diabetes.

Reducing calories, saturated fats, and cholesterol may significantly reduce cholesterol levels.

If high cholesterol and triglyceride levels continue despite diet changes, your doctor may recommend medicine to lower your cholesterol. Medicine to lower cholesterol levels include:
 * Bile acid-sequestering resins
 * Fibrates
 * Nicotinic acid
 * Statins

Prognosis
Persons with this condition have an increased risk for coronary artery disease and peripheral vascular disease.

With treatment, most people show a significant reduction in lipid levels.

Possible Complications

 * Heart attack
 * Stroke
 * Peripheral vascular disease
 * Intermittent claudication
 * Gangrene of the lower extremities

Prevention
Screening the family members of those with familial dysbetalipoproteinemia may lead to early detection and treatment.

Early treatment and avoiding other risk factors for vascular disease (such as smoking) are crucial to preventing early heart attacks, strokes, and blocked blood vessels.