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.

Alternative Names

Causes

The condition is caused by a gene defect that results in a build up of large lipoprotein particles that contain both cholesterol and triglycerides. The disease is linked to defects in the gene for apolipoprotein E in many cases.

The condition increases one's risk for coronary artery disease and peripheral vascular disease.

Hypothyroidism, obesity, or diabetes can make the condition worse. Risk factors include a family history of familial dysbetalipoproteinemia 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, which can make dysbetalipoproteinemia appear in persons who would otherwise not have the condition.

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 include:

• Bile acid-sequestering resins
• Fibrates
• Nicotinic acid
• Statins

Outlook (Prognosis)

Individuals with this form of hyperlipidemia have a significantly increased risk for coronary artery 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

When to Contact a Medical Professional

Call your health care provider if symptoms worsen, do not improve with treatment, or new symptoms develop. Call a genetic counselor if there is a family history of dysbetalipoproteinemia.

Prevention

Screening for family members of people 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.

Email to a Friend