Antiphospholipid syndrome, also called Hughes syndrome or antiphospholipid antibody syndrome, is described in the packet definition as a disorder caused by autoantibodies directed against phospholipids, producing a hypercoagulable state. The definition states that this state may result in blood clots, stroke, heart attack and, in women, significant pregnancy-related complications including miscarriage and stillbirth. Prevalence is not certified in this packet.

The packet lists phenotypes with HPO frequency categories. Intrauterine growth retardation is listed as very frequent (80-99%). Frequent features (30-79%) include ischemic stroke, transient ischemic attack, arterial thrombosis, venous thrombosis, hypercoagulability, hypertension, premature birth, female infertility, fatigue, pain, livedo racemosa and livedo reticularis. Frequent laboratory findings include antiphospholipid antibody positivity, lupus anticoagulant, and anticardiolipin and anti-beta-2-glycoprotein I antibody positivity. Features listed as occasional (5-29%) include gangrene and several further antiphospholipid antibody positivities. Age of onset is not certified in this packet.

Per the packet definition, the condition is caused by autoantibodies directed against phospholipids. The packet lists no associated genes and no inheritance pattern, so no genetic cause or mode of inheritance is certified here. The definition notes an association with other autoimmune disorders, most commonly lupus erythematosus, and with infections including syphilis and Lyme disease.

The packet does not certify diagnostic methods or diagnostic criteria for this condition. The phenotype list includes several antibody findings and lupus anticoagulant, but the packet presents these as phenotypes, not as diagnostic criteria.

The packet certifies no foundational therapies, no management guidance and no FDA-approved treatments for antiphospholipid syndrome, so none are described here. An orphan-drug designation record for pentadecanoic acid (Behind the Rainbow LLC) concerns a different indication, PIGW-CDG, and a designation is not an approval.

Prognosis is not certified in this packet, and no natural history information is provided.

The packet lists clinical trial records from ClinicalTrials.gov, including NCT07757789 (a multicenter cohort study of thrombocytopenia trajectories in antiphospholipid syndrome, not applicable phase, recruiting, sponsor New Valley University, 2026-07-01 to 2027-12-31) and NCT07875153 (anticoagulant cessation after loss of antiphospholipid autoantibodies in thrombotic antiphospholipid syndrome, phase 3, not yet recruiting, sponsor Assistance Publique - Hopitaux de Paris, 2026-12-01 to 2031-01-01). Other listed records enroll people with refractory autoimmune diseases more broadly. A trial title is not a claim about an intervention's effect. The packet's search link points to ClinicalTrials.gov.