Familial combined hyperlipidemia (FCHL) is an inherited disorder that raises the levels of certain lipids (fats) in your blood. Specifically, it raises your LDL “bad” cholesterol and triglyceride levels. Too much of these in your blood can increase your risk of cardiovascular disease and stroke.
FCHL is one of several types of genetic lipid disorders, but it is also the most common. According to a 2019 review, it affects about
Lipid disorders can often be treated effectively with statins and other cholesterol-lowering medications, as well as adopting healthy lifestyle behaviors, such as regular exercise and maintaining a healthy weight.
Hyperlipidemia vs. hypercholesterolemia
Hyperlipidemia can refer to abnormally high levels of several lipid types, including triglycerides.
Hyperlipidemia can develop in one of two ways:
- Acquired hyperlipidemia refers to high lipid levels due to an underlying condition such as obesity, diabetes, or a sedentary lifestyle.
- Familial hyperlipidemia is caused by a mutation on
chromosome 19. One or both parents may pass down this genetic mutation.
There are several inherited lipid disorders. Each one affects your lipid levels in a different way. The main types of familial lipid disorders include:
- FCHL: This usually means your LDL cholesterol level is above 190 mg/dL. You also have high total cholesterol and triglycerides, but low HDL (“good”) cholesterol.
- Familial defective apolipoprotein B100: Apolipoprotein B100 is a type of protein and is a main building block of LDL cholesterol. This condition usually leads to high LDL levels (160 mg/dL to 330 mg/dL).
- Familial dysbetalipoproteinemia: This is due to a defect in the gene for apolipoprotein E, a protein that “packages” lipids so they can move through your bloodstream. The condition leads to high levels of total cholesterol and triglycerides.
- Familial hypertriglyceridemia: This causes excessive production of very low-density lipoproteins (VLDL). This, in turn, causes high levels of triglycerides (200 to 500 mg/dL).
- Heterozygous familial hypercholesterolemia (HeFH): HeFH occurs when one parent passes down the mutated gene that causes familial hypercholesterolemia. It leads to high LDL levels (190 to 350 mg/dL). If both parents pass down the mutated gene, the condition is called homozygous familial hypercholesterolemia (HoFH).
While advancing age is a major risk factor for acquired lipid disorders, it is not a risk factor for familial lipid disorders, which are present at birth.
People from the following racial or ethnic backgrounds may be
- Ashkenazi Jewish
- French Canadian
The degree to which familial hyperlipidemia raises lipid levels varies from one person to another.
You can have familial hyperlipidemia and experience no noticeable symptoms. However, as the condition progresses, you may experience:
- chest pain
- foot sores that don’t heal
- leg cramps, especially in the calves
Because you often have no symptoms with familial hyperlipidemia, the only way to know for sure is with a blood test. Acquired hyperlipidemia will usually show up in routine blood work in adulthood. With familial hyperlipidemia, high lipid levels can be present in teenagers.
If you have no obvious symptoms, but your blood work turns up unusually high lipid levels, your doctor may want to investigate the possibility of familial hyperlipidemia. They may run additional tests to confirm initial test results.
Your doctor will also consider your personal and family history. If you have a family history of lipid disorders or a parent who had a heart attack at a relatively young age, be sure to share that information with your doctor. It may help them to make a proper diagnosis.
Your doctor may also recommend genetic testing. The
Can I prevent hyperlipidemia if I have a family history of it?
Because it is an inherited condition, you cannot prevent familial hyperlipidemia. But you can work closely with your doctor to lower your risk of cardiovascular problems. This includes taking cholesterol-lowering medications as prescribed.
You may be able to enjoy a long and healthy life even with hyperlipidemia. The key will be to understand that the condition is chronic, so ongoing treatment will be necessary.
Inherited lipid disorders tend to speed up cardiovascular complications. This is because the damage from elevated lipid levels starts much earlier in life.
The main concern with FCHL is the increased risk of heart disease, including a heart attack or stroke at an early age.
High levels of LDL cholesterol in the blood make it more likely you will develop a condition called atherosclerosis. That’s when your arteries narrow due to a buildup of plaques composed of cholesterol and other substances. Atherosclerosis is a major risk factor for heart attack and other cardiovascular problems.
Higher rates of obesity and glucose intolerance — both risk factors for type 2 diabetes — are also more common among people with familial hyperlipidemia.
Treating hyperlipidemia usually requires a statin, a daily drug to drive down your LDL level. Statins may also lower your triglycerides.
Other cholesterol-lowering drugs include ezetimibe (Zetia), which you might take in addition to a statin. Your doctor may also prescribe PCSK9 inhibitors, which are expensive medications doctors inject under your skin every month or so.
Your doctor may also advise you to exercise regularly and follow a balanced plant-based diet low in trans and saturated fats.
Though it’s a major risk factor for heart disease, familial hyperlipidemia is treatable. But because it is a serious, lifelong condition, it requires ongoing and often aggressive blood lipid control with medications and lifestyle changes.
People with familial lipid disorders are more likely to have heart disease at a younger age than the general population. Studies suggest that early testing and diagnosis can improve the life expectancy for people with FCHL.
Familial hyperlipidemia refers to a set of inherited disorders that cause your blood lipid levels to be very high. The most common of these conditions is familial combined hypercholesterolemia (FCHL).
If you are diagnosed with a familial lipid disorder, you will have to monitor your LDL and triglyceride levels regularly. It’s helpful to also track your HDL levels, as higher HDL levels can help lessen the risks posed by high LDL. You will also need to be vigilant about taking your medications and following a heart-healthy lifestyle.
Early diagnosis and treatment are key to improving your outlook. Because these conditions are rare, you may need to talk with a doctor who specializes in treating lipid disorders. Talking with a genetics counselor may also help you to better understand how your condition could affect you and your family.