Apolipoprotein A-I Deficiency
What is Apolipoprotein A-I Deficiency?
Apolipoprotein A-I deficiency is a rare genetic condition caused by mutations in the APOA1 gene. This gene provides instructions for making a protein called apolipoprotein A-I, which is the main structural building block of HDL cholesterol. HDL cholesterol is often called good cholesterol because it helps remove excess cholesterol from your arteries and carries it back to your liver.
When you have this deficiency, your body cannot make enough functional apolipoprotein A-I protein. This causes extremely low levels of HDL cholesterol, typically below 10 mg/dL. Normal HDL levels are above 40 mg/dL for men and above 50 mg/dL for women. Without enough HDL cholesterol, your body struggles to remove cholesterol from your blood vessels.
This condition disrupts a process called reverse cholesterol transport, which is your body's natural system for clearing cholesterol from arteries. When this system fails, cholesterol builds up in artery walls much earlier in life. This buildup, called atherosclerosis, significantly increases your risk of heart attack and stroke at a young age.
Symptoms
- Cloudy or milky appearance of the corneas in the eyes
- Orange or yellow tonsils due to cholesterol deposits
- Enlarged liver or spleen detected during physical exam
- Chest pain or angina from early coronary artery disease
- Heart attack or stroke at an unusually young age
- Fatty deposits in the skin called xanthomas
Many people with this condition have no obvious symptoms in childhood or early adulthood. The first sign is often a heart attack or cardiovascular event in their 30s or 40s. Some people discover they have the condition only through routine blood work showing extremely low HDL levels.
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Causes and risk factors
Apolipoprotein A-I deficiency is caused by mutations in the APOA1 gene that you inherit from your parents. When both copies of this gene have mutations, your body cannot produce functional apolipoprotein A-I protein. This inheritance pattern is called autosomal recessive, meaning you need to inherit one mutated gene from each parent to develop the condition. Parents who carry one mutated copy typically have normal or only slightly reduced HDL levels.
Because this is a genetic condition present from birth, lifestyle factors do not cause it. However, other factors can worsen cardiovascular risk in people with this deficiency. Smoking, high blood pressure, diabetes, obesity, and a diet high in saturated fats can accelerate artery damage. A family history of very low HDL cholesterol or early heart disease may suggest this condition runs in your family.
How it's diagnosed
Apolipoprotein A-I deficiency is diagnosed through blood tests that measure your HDL cholesterol levels and HDL particle composition. A standard lipid panel will show severely low HDL cholesterol, typically below 10 mg/dL. Advanced testing can measure HDL Large particles, which are almost completely absent in people with this condition. These tests help doctors distinguish this rare genetic disorder from other causes of low HDL.
Rite Aid offers testing for HDL cholesterol and HDL Large particles as part of our flagship preventive health panel. Getting tested regularly helps catch extremely low HDL levels early, even before symptoms appear. If blood tests suggest apolipoprotein A-I deficiency, your doctor may order genetic testing to confirm mutations in the APOA1 gene. Early diagnosis allows you to start preventive treatments to protect your heart.
Treatment options
- Regular cardiovascular monitoring with stress tests and imaging studies
- Statin medications to lower LDL cholesterol and reduce overall cardiovascular risk
- Blood pressure medications to control hypertension if present
- Aspirin or other antiplatelet drugs to prevent blood clots
- Heart-healthy diet low in saturated fats and trans fats
- Regular physical activity to support cardiovascular health
- Smoking cessation and avoiding secondhand smoke exposure
- Maintaining a healthy weight through nutrition and movement
- Managing diabetes and blood sugar if present
- Genetic counseling for family planning decisions
Concerned about Apolipoprotein A-I Deficiency? Get tested at Rite Aid.
- Simple blood draw at your nearest lab
- Results in days, not weeks
- Share results with your doctor
Frequently asked questions
Low HDL is common and can have many causes including diet, obesity, and genetics. Apolipoprotein A-I deficiency is an extremely rare genetic condition causing severely low HDL, typically below 10 mg/dL. Most people with regular low HDL have levels between 30 and 40 mg/dL. The genetic form involves absent or dysfunctional apolipoprotein A-I protein.
Apolipoprotein A-I deficiency is extremely rare, with only a few hundred documented cases worldwide. Most people with low HDL do not have this genetic condition. The condition requires inheriting two mutated copies of the APOA1 gene, one from each parent. Carriers with one mutated copy are much more common but typically have normal or near-normal HDL levels.
Apolipoprotein A-I deficiency is a genetic condition you are born with. However, symptoms may not appear until adulthood when cardiovascular disease develops. Blood tests can detect extremely low HDL levels at any age. Many people discover they have the condition during routine health screenings or after a cardiovascular event.
HDL Large measures the number of large HDL particles in your blood. These particles are the most effective at removing cholesterol from arteries. In apolipoprotein A-I deficiency, HDL Large particles are almost completely absent because apolipoprotein A-I is the main structural protein needed to build them. This test helps confirm the genetic deficiency.
Supplements that raise HDL in healthy people typically do not work in apolipoprotein A-I deficiency. Your body cannot make functional HDL particles without apolipoprotein A-I protein. Treatment focuses on lowering LDL cholesterol, controlling other risk factors, and monitoring heart health. Always discuss supplements with your doctor before starting them.
Your doctor will likely recommend blood tests at least twice per year to monitor your cholesterol levels and cardiovascular risk. Regular testing helps track how well treatments are working. You may need more frequent testing if you start new medications or if your cardiovascular risk changes. Rite Aid offers convenient testing at Quest Diagnostics locations nationwide.
Yes, lifestyle changes are essential even though they cannot fix the genetic deficiency. Not smoking, eating a heart-healthy diet, exercising regularly, and maintaining a healthy weight all reduce cardiovascular risk. These changes help prevent additional damage to your arteries. Combining lifestyle changes with medications offers the best protection for your heart.
If you have apolipoprotein A-I deficiency and your partner does not carry the mutation, your children will be carriers but will not have the condition. If your partner is also a carrier, each child has a 25 percent chance of having the condition. Genetic counseling can help you understand risks and testing options for family planning.
There is currently no cure for this genetic condition. Research is exploring gene therapy and infusions of synthetic apolipoprotein A-I protein, but these are not yet available as standard treatments. Current care focuses on preventing heart disease through medications, lifestyle changes, and close monitoring. Early detection and proactive management significantly reduce cardiovascular events.
Schedule an appointment with your doctor to discuss your results and possible causes. Very low HDL below 10 mg/dL may suggest apolipoprotein A-I deficiency, but other conditions can also lower HDL. Your doctor may order additional tests including HDL particle analysis and genetic testing. Starting protective treatments early can reduce your risk of heart disease.