Pure hypercholesterolemia or familial hypercholesterolemia is a condition where a person has high cholesterol levels due to a genetic abnormality.
While high cholesterol is often the result of eating a high-fat diet, pure hypercholesterolemia is unrelated to lifestyle or diet.
However, pure hypercholesterolemia is no less dangerous to a person’s overall health. However it is caused, excess cholesterol can increase a person’s risk of heart disease.
Pure hypercholesterolemia is passed down to a person by their parents because of a genetic mutation on chromosome 19.
The condition affects a person’s liver. The liver is responsible for producing cholesterol, which helps create healthy cell walls. However, when a person has pure hypercholesterolemia, the liver is unable to recycle cholesterol and regulate cholesterol levels. As a result, the amount of cholesterol builds up in the body.
Two forms of the condition exist: heterozygous familial hypercholesterolemia (HeFH) and homozygous familial hypercholesterolemia (HoFH).
The HeFH condition occurs when a person inherits pure hypercholesterolemia from one parent.
The major risk factor for developing pure hypercholesterolemia is having one or both parents with a history of the condition.
If a person has pure hypercholesterolemia or has a parent with the condition, it’s important they have their children’s cholesterol levels tested. This testing should occur when the children are between the ages of 2 and10 years.
If a parent has pure hypercholesterolemia, there is a 50 percent chance they will pass the condition on to their child. Genetic counselors can help a person more closely examine the chances of passing the condition on to their child.
People of certain ethnicities are at a higher risk of experiencing the condition. These include, traditionally, a person experiences high cholesterol later in life when they have, perhaps, led a less-than-healthful lifestyle for many years.
However, pure hypercholesterolemia occurs from birth and unfortunately high cholesterol does not often present many symptoms in its early stages.
A blood test will usually reveal the levels of low-density lipoprotein (LDL), often called “bad” cholesterol, in the blood. Doctors would consider levels of 190 milligrams per deciliter (mg/dL) or higher in adults, and 160 mg/dL or higher in children, as very high.
Although symptoms rarely occur, some people who have pure hypercholesterolemia may experience:
Doctors will diagnose the condition by finding out about the person’s symptoms and by taking a family history. A doctor may note any cholesterol deposits that have built up in the body, especially on or around the eyes.
A doctor will probably order blood tests to find out what a person’s total cholesterol levels are. Results that show total cholesterol levels higher than 300 mg/dL or higher than 250 mg/dL in children, will be cause for concern.
Genetic testing can reveal the genetic mutation on chromosome 19 that would indicate pure hypercholesterolemia.
A doctor may also order tests to determine the overall impact that pure hypercholesterolemia has had on a person’s health. This could include a cardiac stress test or an echocardiogram.
Treatments for pure hypercholesterolemia often depend upon how severe the cholesterol levels and symptoms are. Almost all people with the condition will need to take a prescription medication to reduce overall cholesterol levels.
The most common medications are called “statins.” An example is atorvastatin
Sometimes doctors will prescribe additional medications known to lower cholesterol, such as: People with severely high cholesterol levels may also need to undergo a procedure called LDL-apheresis. This process involves the removal of excess cholesterol from the blood. It is performed on a weekly or twice-weekly basis.
In very rare and extreme cases, a person may require a liver transplant.
Lifestyle changes can also help to keep cholesterol levels as low as possible. Examples of healthy lifestyle measures include:
Doctors will often recommend that a person with pure hypercholesterolemia take low-dose aspirin in an attempt to prevent blood clotting and reduce the risk for stroke and coronary artery disease.
Researchers are currently conducting clinical trials and studies regarding medications in a new class of drugs called proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors.
The amount of LDL in the body is normally controlled by specialist receptors. When a person has hypercholesterolemia, these receptors do not function properly. These medications help these receptors to continue working and as a result, the body is better able to process LDL cholesterol.
The U.S. Food and Drug Administration (FDA) have approved evolocumab (Repatha), a PCSK9 medication to treat patients with familial hypercholesterolemia where the genetic mutation was passed down by one parent. The medication isn’t considered a first-line treatment, however.
Doctors will typically only prescribe the evolocumab if a person isn’t responding to statin therapy, according to the American Pharmacists Association.