{"id":"factor-v-leiden","name":"Factor V Leiden (R506Q)","shortName":"Factor V Leiden","aliases":["Factor V Leiden","Factor V Leiden Mutation","FVL","F5 R506Q","F5 Leiden","FV Leiden","F5 G1691A","Factor V (Leiden) Genotype","Factor V Leiden Mutation, Blood","Factor V Leiden (R506Q) Mutation","Factor V Leiden R506Q","Factor V Leiden Genotyping","Factor V Leiden Mutation Analysis","F5 c.1691G>A","F5 c.1601G>A","F5 p.Arg506Gln","F5 p.Arg534Gln","rs6025","Factor 5 Leiden"],"abbreviations":["FVL","R506Q"],"loinc":[{"code":"21668-9","primary":true},{"code":"91712-0","primary":false},{"code":"21667-1","primary":false}],"specimen":"whole-blood","units":[],"referenceRanges":[],"review":{"status":"ai-verified","label":"AI-verified against cited sources. Awaiting expert review","lastReviewed":"2026-10-03"},"summary":"A DNA test for a common inherited change in the F5 gene that lets blood clot a little more easily. Most people who carry it never develop a problem clot.","url":"https://bloodtesttracker.com/markers/factor-v-leiden","notice":"Information, not medical advice. Ranges differ between labs, so the range on your own report is the one your result is judged against."}