Familial hypercholesterolemia

This information is useful for children, adults, and older adults
a man smiling after exercise, possibly with familial hypercholesterolemia

Credit: Getty Images

Many people mistakenly believe that cholesterol is, in and of itself, harmful to your health, but that’s not actually the case. Cholesterol is a substance we need for our body to function well, but too much of it can increase your risk for heart disease. Cholesterol is produced mainly by the liver in particles known as lipoproteins. There are two important types of cholesterol-containing particles in humans and the ratio of one type to the other is an important indicator of your risk for heart disease. In layman language these are called “good” and “bad” cholesterol. The so-called bad cholesterol (LDL) enters the heart arteries and cause heart disease and the so-called good cholesterol return cholesterol from body’s tissues to the liver to be used for making necessary proteins.

The problem with cholesterol levels is that it is not something you can feel or be aware of without a routine blood test. The only way to find out if you have high levels of “bad” cholesterol, or its correct term low-density lipoprotein (LDL), is to have regular screenings done.

Cholesterol levels are influenced by a variety of factors, including genetics and lifestyle. Some people with high LDL levels can achieve healthier levels by changing their food choices and becoming more active. However, lifestyle adjustments won’t be enough for those who are born with a genetic mutation that causes abnormally high LDL cholesterol levels. Familial hypercholesterolemia (FH) is a genetic disorder that interferes with the body’s ability to process LDL cholesterol. 

What is the role of cholesterol in the body? 

Cholesterol is necessary for making cell membranes, hormones, and vitamin D. LDLs act like taxis in the body, helping cholesterol travel throughout the bloodstream and dropping if off where it is needed. Once the work has been done, the other type of cholesterol, called high-density lipoprotein (HDL)—known as the “good” cholesterol—absorbs the remaining cholesterol (removing it from the peripheral tissues) and carries it to the liver, where it is processed out of the body. 

When too much LDL cholesterol is in the body, it accumulates on the blood vessel walls, forming a yellowish, waxy layer called plaque. This can cause the vessel walls to shrink or harden (called atherosclerosis), which can lead to coronary artery disease (CAD). A buildup can also block blood vessels, leading to a heart attack or stroke at a very young age. While everyone is at risk of plaque buildup as they grow older, a person with FH will have unusually high levels of LDL cholesterol from birth and so the damaging accumulation begins much earlier in life. 

FH is one of the more common genetic disorders in the U.S., affecting an estimated 1 in 250 people. FH is what’s known as an autosomal dominant disorder, which means that a child has a 50 percent chance of inheriting a mutated gene from a parent who has the mutation. If left untreated, the genetic condition can significantly increase a person’s risk of developing atherosclerosis (a buildup of plaque inside the arteries, which can lead to cardiovascular disease). The good news is that most FHs can be treated and managed well with cholesterol-lowering medications and regular screening checkups.  

The Centers for Disease Control and Prevention (CDC) lists FH as a “tier one” genomic health condition, which means that studies have shown that medical interventions can decrease the likelihood a person with the genetic mutation will develop the disease. When treated from an early age, FH is a manageable condition. The CDC recommends a cholesterol screening once between ages 9 and 11; again between 17 and 21; and every 4 to 6 years for adults. However, patients may not be aware of these voluntary guidelines and pediatricians are not required to screen cholesterol levels, though the American Academy of Pediatrics also recommends testing between ages 9 and 11. 

If left untreated, FH can be a life-threatening disorder.  

At Yale Medicine, our physicians work with patients diagnosed with FH closely to ensure they have the most personalized medication and treatment program possible. “We have experts that can diagnose the condition and provide best therapies. Our cardiovascular genetic center has the expertise for the diagnosis and management of patient with this disorder,” says Arya Mani, MD, director of the Yale Medicine Cardiovascular Genetics Program.