Familial chylomicronemia

Definition

Familial lipoprotein lipase deficiency is a group of rare genetic disorders in which a person lacks a protein needed to break down fat molecules. The disorder causes large amounts of fat to build up in the blood.

Alternative Names

Causes

Familial lipoprotein lipase deficiency is usually caused by a defective gene. The gene is passed down through families in an autosomal recessive manner.

Persons with this condition do not have a substance called lipoprotein lipase. Without this, the body cannot break down fat from digested food. Fat particles called chylomicrons build up in the blood.

Risk factors include:

• Family history of lipoprotein lipase deficiency
• Very high triglycerides in the blood
• Multiple unexplained episodes of pancreatitis
• Failure to thrive in infancy

The disorder affects about 1 out of 1,000,000 people. The condition is usually first seen during infancy or childhood.

Symptoms

• Abdominal pain (may appear as colic in infancy)
• Nausea
• Vomiting
• Loss of appetite
• Failure to thrive in infancy
• Musculoskeletal pain
• Fatty deposits in the skin (xanthomas)

Exams and Tests

A physical examination may reveal fatty deposits in the skin, a swollen liver and spleen, and yellowing of the eyes and skin (jaundice). An eye examination reveals pale retinas and white-colored blood vessels in the retinas.

Blood tests will be done to check cholesterol and triglyceride levels. A special blood test may be done after you are given blood thinners through a vein. This test looks for lipoprotein lipase activity in your blood.

Genetic tests may be done, including one for apolipoprotein CII deficiency.

Treatment

Treatment is intended to control the symptoms and blood triglyceride levels with a very low-fat diet. Fat intake usually must be less than 20 grams per day to keep the symptoms from coming back.

Twenty grams of fat is equivalent to one of the following:

• 2, 8-ounce glasses of whole milk
• 4 teaspoons of margarine
• 4-ounce serving of meat

The average American diet has an average fat content of up to 45% of total calories. Fat-soluble vitamins A, D, E, and K and mineral supplements are recommended. Dietary counseling may be helpful for patients trying to stick to a strict diet and maintain adequate calorie and nutrient intake. Pancreatitis responds to conventional treatments for that disorder.

Outlook (Prognosis)

Persons with this condition who follow a very low-fat diet may live into adulthood.

Possible Complications

Pancreatitis and recurrent episodes of abdominal pain may develop.

Xanthomas are not usually painful unless they are rubbed a lot.

When to Contact a Medical Professional

Call your health care provider for screening if someone in your family has lipoprotein lipase deficiency. Genetic counseling is recommended for anyone with a family history of this disease.

Prevention

There is no known prevention for this rare, inherited disorder. Awareness of risks may allow early detection. Following a very low fat diet can dramatically improve the symptoms of this disease.

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