Familial Hypercholesterolemia
FH runs in the family
You are born with FH
People with Familial Hypercholesterolemia (FH) have a defect (a disease-causing genetic variant) in their DNA. Hereditary traits are stored in DNA. Your body needs cholesterol as a building block for cells and hormones. Part of it comes from your diet, and part is produced by the liver itself.
LDL cholesterol, also known as 'bad cholesterol', stands for 'low-density lipoprotein'. It is a fatty substance that transports cholesterol from the liver to the rest of the body. The liver filters the bad LDL cholesterol out of the blood using a specific protein (a 'receptor'). This keeps the system in balance. In people with FH, the body is less effective at filtering LDL cholesterol out of the blood. This is due to a defect in one of the following three genes:
- LDL receptor gene: the body produces insufficient or non-functioning LDL receptors
- PCSK-9 gene: LDL receptor is broken down more quickly
- APO-B gene: the binding of LDL to the LDL receptor is disrupted.
You don't immediately notice high cholesterol
The consequences of FH
FH is characterized by lifelong high LDL cholesterol levels in the blood. This leads to arteriosclerosis (atherosclerosis), in which plaque can accumulate in the artery walls.
Atherosclerosis increases the risk of serious cardiovascular diseases, such as heart attack, stroke, and problems with blood flow to the legs. High cholesterol does not cause any immediate symptoms, but the consequences can be life-threatening.
FH is a dominantly inherited condition. First-degree relatives of someone with FH have a 50% chance of having the disease. During family screening, first-degree relatives are tested to see if they also have FH. With FH, there is a high chance that someone has elevated LDL cholesterol from birth. Therefore, it is important to know at a young age whether or not you have FH.
Forms of FH
The most common form is heterozygous FH. This occurs in 1 in 300 people. FH is then inherited from one of the parents. This can be treated effectively to prevent premature cardiovascular disease.
The rare form is homozygous FH. In this case, cholesterol levels are extremely high. This occurs in 1 in 300,000 people. FH is inherited from both parents. This can lead to cardiovascular disease even in childhood. In addition to medication, the homozygous form is also treated with dialysis.
