- type IIa hyperlipoproteinemia
Familial hypercholesterolemia is an inherited disease that causes
high cholesterol levels.
What is going on in the body?
Normally, the liver regulates the amount of cholesterol, a kind of fat, in the blood. It uses special docking sites, or receptors, to remove extra cholesterol. A person with familial hypercholesterolemia inherits an abnormal gene for the docking site from one or both parents.
If an abnormal gene is inherited from one parent, the body makes only half of the usual number of docking sites. If the abnormal gene is inherited from both parents, the body makes no docking sites. In either case, the level of cholesterol gets too high in the blood. This can lead to heart attacks, strokes, and other diseases.
What are the causes and risks of the condition?
This disease is inherited and occurs in about 1 in 1000 people. The chance of inheriting two bad genes, one from each parent, is 1 in 1,000,000.
What can be done to prevent the condition?
An inherited trait cannot be prevented.
Genetic counseling may be useful to couples with a family history of the disease.
How is the condition diagnosed?
This disease is diagnosed by a blood test and family history. Cholesterol levels are high at birth and increase with age. The average total cholesterol with one abnormal gene is usually 250 to 500 milligrams per deciliter of blood (mg/dl). With two abnormal genes, the average cholesterol level is 500 to 1000 mg/dl. Levels over 200 mg/dl are associated with a higher risk of heart attacks, strokes, and other diseases.
Long Term Effects
What are the long-term effects of the condition?
A person with this disease generally develops artery blockages at an early age. For example, by age 50, a person with this condition is 3 to 10 times more likely than normal to have a heart attack. Heart disease, strokes, and other diseases may also occur. Because of the very high risk of heart attacks, diagnosis and treatment should begin as soon as possible.
What are the risks to others?
This condition is inherited and is not contagious. Children and other family members of affected people should have
cholesterol screening. Early detection and treatment of this condition may delay the complications.
What are the treatments for the condition?
Anyone who has this condition should talk to a healthcare professional. This condition responds to diet changes. Affected people should eat a diet low in fat and cholesterol. Obesity, high blood pressure, and diabetes should be treated. If the individual smokes, he or she should quit as soon as possible, using any of a variety of available methods.
A person with one abnormal gene will need medications to lower the cholesterol level. Examples of medications used include:
- bile acid resins, such as cholestyramine (i.e., Questran) and colestipol (i.e., Colestid),
- statin drugs, such as atorvastatin (i.e., Lipitor), fluvastatin (i.e., Lescol), lovastatin (i.e., Altoprev, Mevacor), pravastatin (i.e., Pravachol), and simvastatin (i.e., Zocor)
- niacin (i.e., Niaspan, Slo-Niacin).
Combinations of medications are often needed. Someone with two abnormal genes is generally treated by an expert in this disease. The use of a machine to filter the blood may be the only good way to lower the cholesterol.
What are the side effects of the treatments?
Since the liver makes cholesterol, most of the medications to lower cholesterol levels may affect the liver. Specific side effects vary by the medication, and may include:
- constipation with bile acid resins
- flushing, itching and increased blood sugar with niacin
- muscle aches with statin drugs
What happens after treatment for the condition?
Treatment is generally needed for life.
How is the condition monitored?
Repeated checks of the
cholesterol level in the blood are done to see how well the treatment is working. Someone taking cholesterol-lowering medications may need periodic liver function tests. If chest pain or shortness of breath occurs, a healthcare professional should be told right away. This may be a sign of a heart attack.