Exams and Tests

A diagnosis of familial hypercholesterolemia (FH) is usually based on:

• A simple blood test to measure the amount of cholesterol in your blood. LDL-cholesterol is much higher among people with FH.

  	Heterozygous FH (more common, one FH gene)	Homozygous FH (less common, two FH genes)
  Typical LDL Levels	Over 190 mg/dL for adults Over 160 mg/dL for children	Over 400 mg/dL

  
  
• A thorough family history. FH runs in families. Your care team will want to know if a close relative has FH, very high LDL cholesterol, or has died from heart or blood vessel disease at an early age.
• A physical exam, to look for any physical signs, including cholesterol deposits or bumps under the skin or around the eyes. 
• Genetic testing may be used to confirm that someone has FH. Testing looks for gene changes, or variants, that have been linked to FH.
  
  If you have a gene variant, you can test to see if other family members also have the same one. In some cases, it’s not possible to find the variant that is causing FH because it hasn’t been discovered yet. A genetic counselor can help answer questions and give advice about testing.

If you have FH, you may be referred to a preventive cardiologist, endocrinologist or lipidologist — a doctor who specializes in treating high cholesterol or lipid disorders.

There are many imaging tests that can look for early development of atherosclerosis (plaque buildup in the arteries) including calcium scoring and CT scans that may help guide your diagnosis or plan.

When Should Screening for FH Begin?

Two types of screening approaches can be used to find FH: universal and cascade. The American Academy of Pediatrics, for example, recommends that all children have their cholesterol levels checked by ages 9 to 11 years old. This universal screening approach can identify children with high LDL cholesterol levels that are caused by genetics or lifestyle habits given the growing number of children who are overweight.

If you have FH, “family tracing” or “cascade screening” with lipid and/or genetic testing can help identify other first-degree family members who might be affected.

If there is suspected or confirmed FH in a parent, consider screening children starting at age 2. If both parents have FH, consider screening their children at birth.