Familial lipid disorders

A familial lipid disorder is a condition that runs in families. It causes very high levels of cholesterol. This condition can cause a person to get coronary artery disease (CAD) while still young. Because familial lipid disorders are rare, your doctor may only suspect one if you have:

• Very high cholesterol levels.
• A family history of high cholesterol.
• A family history of early CAD.
• Certain results from a physical exam.

Your family doctor may not have much experience with familial lipid disorders, so you may have to see a specialist, such as an endocrinologist. And some cardiologists specialize in lipid disorders as well as heart problems.

Types of familial lipid disorders

Disorder	Cholesterol level	Distinguishing characteristics
Familial combined hyperlipidemia (FCHL)	High total cholesterol, usually with high triglycerides High triglycerides and low HDL	Appears in adulthood Happens more often in families with obesity, hypertension, and diabetes
Familial defective apolipoprotein B-100	High LDL
Familial dysbetalipoproteinemia (type 3 hyperlipoproteinemia)	Total cholesterol of 300–600 Triglyceride of 400–800	CAD, heart attack, and stroke at a young age Xanthomas, a skin condition in which small bumps of fat appear under the skin
Familial hypertriglyceridemia	Very high triglycerides	Risk for even higher triglycerides from other causes
Heterozygous familial hypercholesterolemia	Total cholesterol of 325–450	CAD before age 50 Small, pale ring around the iris of the eye Xanthomas on tendons in young adults
Homozygous familial hypercholesterolemia	Total cholesterol of 500–1,000	CAD before age 20 Xanthomas on tendons within the first few months of life