National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Antiphospholipid syndrome



Other Names:
Familial antiphospholipid syndrome; Antiphospholipid antibody syndrome; Lupus anticoagulant, familial; Familial antiphospholipid syndrome; Antiphospholipid antibody syndrome; Lupus anticoagulant, familial; APS; Hughes syndrome See More
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Subtypes:

Antiphospholipid syndrome (APS) is an autoimmune disorder. Signs and symptoms vary, but may include blood clots, miscarriage, rash, chronic headaches, dementia, and seizures.[1] APS occurs when your body's immune system makes antibodies that attack phospholipids. Phospholipids are a type of fat found in all living cells, including blood cells and the lining of blood vessels. Most cases of APS occur in people with no family history of the disorder, however there are rare cases of APS clustering in a family. A widely accepted explanation for APS is that it is caused by a combination of gene mutations (making one more susceptible to APS) and an environmental exposure (such as to a virus). Currently there is not a cure for APS. The goal of treatment is to prevent blood clots from forming and to keep existing clots from getting larger.[2][3][4]
Last updated: 5/25/2016

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.

Showing of 14 |
Medical Terms Other Names
Learn More:
HPO ID
Percent of people who have these symptoms is not available through HPO
Arterial thrombosis
Blood clot in artery
0004420
Autoimmune thrombocytopenia 0001973
Autosomal dominant inheritance 0000006
Blurred vision 0000622
Central retinal artery occlusion 0025342
Iritis
Inflammation of iris
0001101
Keratitis
Corneal inflammation
0000491
Lupus anticoagulant 0025343
Retinal detachment
Detached retina
0000541
Retinal vasculitis 0025188
Scleritis 0100532
Venous thrombosis
Blood clot in vein
0004936
Visual loss
Loss of vision
Vision loss
[ more ]
0000572
Vitritis 0011531
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Last updated: 7/1/2020

Antiphospholipid syndrome (APS) is an autoimmune disorder. It occurs when your body's immune system makes antibodies that attack phospholipids (a type of fat found in living cells). The exact reason for this is not known. While APS is not passed through families in a predictable pattern, genetics are thought to play a role. A widely accepted explanation for APS is that it is caused by a combination of gene mutations (making one more susceptible to APS) and an environmental exposure (such as a viral infection).[2][3][4]

Research has found a few gene changes that occur in people with APS, however the contribution of these genetic changes to the development of the condition is unclear.[5]  Little is known about specific environmental triggers. Known risk factors include female sex and having other autoimmune-type disorders (such as Lupus).[4]

Some people have APS antibodies, but have no signs or symptoms. These people are also at an increased risk for APS. In these cases, APS symptoms (for example blood clots) can be triggered by smoking, prolonged bed rest, pregnancy and the postpartum period, birth control pills, hormone therapy, cancer, and kidney disease.[3]
Last updated: 5/25/2016

The resources below provide information about treatment options for this condition. If you have questions about which treatment is right for you, talk to your healthcare professional.

Management Guidelines

  • Project OrphanAnesthesia is a project whose aim is to create peer-reviewed, readily accessible guidelines for patients with rare diseases and for the anesthesiologists caring for them. The project is a collaborative effort of the German Society of Anesthesiology and Intensive Care, Orphanet, the European Society of Pediatric Anesthesia, anesthetists and rare disease experts with the aim to contribute to patient safety.

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources


Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • ClinicalTrials.gov lists trials that are related to Antiphospholipid syndrome. Click on the link to go to ClinicalTrials.gov to read descriptions of these studies.

    Please note: Studies listed on the ClinicalTrials.gov website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.

Patient Registry

  • The Autoimmune Registry supports research for Antiphospholipid syndrome by collecting information about patients with this and other autoimmune diseases. You can join the registry to share your information with researchers and receive updates about participating in new research studies. Learn more about registries.

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 Supporting this Disease

Organizations Providing General Support


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 Antiphospholipid syndrome. This website is maintained by the National Library of Medicine.
  • The Lupus Foundation of America has an information page on lupus and antiphospholipid antibodies. Click on Lupus Foundation of America to view the information page.
  • The March of Dimes has an information page on thrombophilia and pregnancy.
  • The MayoClinic.com has a information page on antiphospholipid syndrome. Click on MayoClinic.com to view the information page.
  • The National Human Genome Research Institute's (NHGRI) website has an information page on this topic. NHGRI is part of the National Institutes of Health and supports research on the structure and function of the human genome and its role in health and disease.
  • The National Institute of Neurological Disorders and Stroke (NINDS) collects and disseminates research information related to neurological disorders. Click on the link to view information on this topic.
  • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.

In-Depth Information

  • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
  • MeSH® (Medical Subject Headings) is a terminology tool used by the National Library of Medicine. Click on the link to view information on this topic.
  • 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 Antiphospholipid syndrome. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know.


  1. NINDS Antiphospholipid Syndrome Information Page. National Institute of Neurological Disorders and Stroke. June 30, 2015; https://www.ninds.nih.gov/Disorders/All-Disorders/Antiphospholipid-Syndrome-Information-Page.
  2. How Is Antiphospholipid Antibody Syndrome Diagnosed?. National Heart, Lung and Blood Institute. May 17, 2012; https://www.nhlbi.nih.gov/health/health-topics/topics/aps/diagnosis.
  3. Who Is at Risk for Antiphospholipid Antibody Syndrome?. National Heart, Lung and Blood Institute. May 17, 2012; http://www.nhlbi.nih.gov/health/health-topics/topics/aps/atrisk.
  4. Schur PH. Pathogenesis of the antiphospholipid syndrome. UpToDate. September 18, 2014; http://www.uptodate.com/contents/pathogenesis-of-the-antiphospholipid-syndrome.
  5. Learning About Antiphospholipid Syndrome (APS). National Human Genome Research Institute (NHGRI). December 15, 2010; http://www.genome.gov/17516396.
  6. Movva S. Antiphospholipid Syndrome. Medscape Reference. March 24, 2015; http://emedicine.medscape.com/article/333221-overview.