{"entity":{"id":"flt3-itd-allelic-ratio","kind":"term","name":"FLT3-ITD allelic ratio","aka":[],"tldr":"How much of the FLT3 gene in the leukaemia carries the internal duplication, measured as the ratio of mutant to normal copies. The 2017 European LeukemiaNet guidelines used it to grade risk; the 2022 update dropped it because midostaurin and quizartinib help regardless of the ratio.","summary":"Ratio of mutant to wild-type FLT3-ITD alleles by fragment analysis; ≥0.5 was 'high'. ELN 2017 used it for risk; ELN 2022 removed it, treating all FLT3-ITD as intermediate risk given midostaurin and quizartinib benefit across ratios. Still reported by many labs and relevant to interpreting older trials.","asOf":"2026-09-07","wikipedia":"https://en.wikipedia.org/wiki/CD135","links":[{"label":"Dohner et al., Diagnosis and management of AML in adults: 2022 ELN recommendations (Blood 2022)","url":"https://doi.org/10.1182/blood.2022016867"}],"tags":[],"related":[],"cancers":["aml"],"sections":[],"technologies":[],"targets":["flt3"],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":["eln-risk"],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"category":"Genomics & genetics"},"route":"/terms/flt3-itd-allelic-ratio/","neighbours":{"cancer":[{"id":"aml","kind":"cancer","name":"Acute myeloid leukaemia","route":"/cancers/aml/"},{"id":"aml-flt3","kind":"cancer","name":"FLT3-mutated acute myeloid leukaemia","route":"/cancers/aml-flt3/"}],"target":[{"id":"flt3","kind":"target","name":"FLT3","route":"/targets/flt3/"}],"term":[{"id":"eln-risk","kind":"term","name":"ELN 2022 risk classification","route":"/terms/eln-risk/"}],"trial":[{"id":"ratify","kind":"trial","name":"RATIFY (CALGB 10603)","route":"/trials/ratify/"}],"biomarker":[{"id":"flt3-itd","kind":"biomarker","name":"FLT3-ITD (internal tandem duplication)","route":"/biomarkers/flt3-itd/"}]}}