(abbreviated FH) is a genetic disorder characterized by high cholesterol levels, specifically very high levels of low-density lipoprotein (LDL, “bad cholesterol”), in the blood and heart attacks and stroke at a younger than usual age.
Some people with FH may have visible physical signs including swollen tendons on the back of the heel (a), the elbows or the knuckles (b), and also yellow deposits in the skin around the eyes (c,d). A white deposit of cholesterol in the shape of a circle (at 6 and 12 o’clock) may also be seen at the edge of the colored part of the eye (d).
In FH there is a change in the gene that codes for the LDL-receptor. This receptor sits on the surface of cells, especially liver cells, and can be thought of as a tentacle-like molecule that removes cholesterol-containing LDL-C particles from the blood. The change in the LDL-receptor gene results in an abnormal or reduced number of LDL-receptors, making them unable to remove LDL-Cholesterol from the blood. This is the cause of FH.
FH is suspected if there is a family history of heart attack or stroke early in life. If a person suffers a heart attack before the age of 50-60, it may be due to high cholesterol and blood cholesterol levels must be investigated in the family.
Genetic testing may be done to identify the abnormal LDL receptor gene, but is usually not necessary. Signs of FH may also be visible during a physical exam. These can include yellow deposits on the skin around the eyes, a ring on the colored part of the eye, and small masses or thickening on the hands, elbows and/or back of the ankles.
Formal diagnosis of FH can be made by using any one of several sets of criteria, such as the diagnosis guidelines outlined by Make Early Diagnosis Prevent Early Death (MEDPED), the Dutch Lipid Clinic Network, and the Simon-Broome Registry. Your lipid specialist can talk with you in greater details about how to diagnose FH.
In families where FH has been diagnosed, it is advised that children are tested for FH at about age 2. This allows early dietary changes to encourage healthy eating.
Some children with very high cholesterol levels, or a close family member with very early onset heart attack or stroke, may need treatment with medications to lower their blood cholesterol to a safer level.
Drug treatments include statins, resins, cholesterol absorption inhibitors (ezetimibe), and niacin-based therapies. Your doctor might treat you with one or more of these four types of medications. Medication, a healthy lifestyle, and heart friendly diet need to be continued throughout life. If LDL-C is reduced sufficiently, cholesterol deposits in blood vessels and around the eyes or tendons may start to shrink.
Dietary changes can lower LDL Cholesterol. For many patients with FH, this may not be enough and a change in diet should be combined with medication. For very severe forms of FH additional dialysis-like cleansing treatment (LDL-apheresis) may be required.