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Disease Profile


Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.

<1 / 1 000 000


US Estimated


Europe Estimated

Age of onset

All ages





Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.


Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.


dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.


recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.


Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.


Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.


Not applicable


Other names (AKA)

Retention of dietary cholesterol and abnormal retention of non-cholesterol sterols in the body; Phytosterolemia; Plant sterol storage disease


Congenital and Genetic Diseases; Endocrine Diseases; Metabolic disorders;


Sitosterolemia is a rare inherited condition in which plant sterols accumulate in the blood and tissues. Plant sterols, including sitosterol, stigmasterol, and campesterol, are fatty substances found in vegetable oils and nuts. Individuals with sitosterolemia have extremely high levels of sitosterol (30 to 100 times higher than normal), along with mildly to moderately elevated levels of cholesterol in their blood. These plant sterols and cholesterol build up in the arteries, leading to premature thickening of the artery walls and early heart disease. Affected individuals may also develop small yellowish growths called xanthomas on or under the skin and in the tendons.[1][2] Sitosterolemia is caused by mutations in the ABCG5 or ABCG8 gene. The condition is inherited in an autosomal recessive pattern.[1][2][3] Treatment involves restricting foods that are high in plant and shellfish sterols, and taking medications that decrease the concentration of these products in the blood.[2][3]


This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Medical Terms Other Names
Learn More:
Percent of people who have these symptoms is not available through HPO
Abdominal pain
Pain in stomach
Stomach pain

[ more ]

Abnormal bleeding
Bleeding tendency
Abnormality of the liver
Abnormal liver
Liver abnormality

[ more ]

Joint pain
Joint inflammation
Autosomal recessive inheritance
Chronic hemolytic anemia
Coronary artery atherosclerosis
Plaque build-up in arteries supplying blood to heart
Episodic hemolytic anemia
Giant platelets
Elevated serum cholesterol
Elevated total cholesterol
Increased total cholesterol

[ more ]

Impaired platelet aggregation
Increased immature red blood cells
Increased number of immature red blood cells

[ more ]

Increased spleen size
Tuberous xanthoma


Sitosterolemia is diagnosed by measuring the levels of plant sterols in the blood, including sitosterol, campesterol, and stigmasterol. Normal cholesterol studies will not diagnosed sitosterolemia because they cannot distinguish among the different sterols. DNA analysis of the ABCG5 and ABCG8 genes can be helpful in detecting mutations and confirming the diagnosis.[2][3]

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.


    The primary goal of treatment is to reduce the concentration of plant sterols in the blood (to below 1 mg/dl, if possible). Sitosterolemia can be managed by restricting floods that have a high concentration of plant and shellfish sterols, and with the use of medications. Foods with high plant sterols include vegetable oils, margarine, nuts, seeds, avocados, and chocolate. The drug ezetimibe may be used to decrease the plant sterol concentration in blood. Cholestyramine has also been used in some individuals.[2][3] If medications don't work, partial ileal bypass surgery may be considered.[3]

    GeneReviews offers additional details about management.


    Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

    Organizations Providing General Support

      Learn more

      These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

      Where to Start

      • Genetics Home Reference contains information on Sitosterolemia. This website is maintained by the National Library of Medicine.

        In-Depth Information

        • GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
        • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
        • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
        • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
        • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
        • PubMed is a searchable database of medical literature and lists journal articles that discuss Sitosterolemia. Click on the link to view a sample search on this topic.


          1. Sitosterolemia. Genetics Home Reference (GHR). May 2013; https://ghr.nlm.nih.gov/condition/sitosterolemia.
          2. What is Sitosterolemia?. Sterol & Isoprenoid Research Consortium. 2016; https://www.rarediseasesnetwork.org/cms/stair/Learn-More/Disorder-Definitions.
          3. Merkens LS, Myrie SB, Steiner RD, Mymin D. Sitosterolemia. GeneReviews. April 4, 2013; https://www.ncbi.nlm.nih.gov/books/NBK131810/.

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