{"doi":"10.1002/gcc.23084","title":"Characterization of unusual <scp>iAMP21</scp> B‐lymphoblastic leukemia (<scp>iAMP21‐ALL</scp>) from the Mayo Clinic and Children's Oncology Group","abstract":"Acute lymphoblastic leukemia (B-ALL) with intrachromosomal amplification of chromosome 21 (iAMP21-ALL) represents a recurrent high-risk cytogenetic abnormality and accurate identification is critical for appropriate clinical management. Identification of iAMP21-ALL has historically relied on fluorescence in situ hybridization (FISH) using a RUNX1 probe. Current classification requires ≥ five copies of RUNX1 per cell and ≥ three additional copies of RUNX1 on a single abnormal iAMP21-chromosome. We sought to evaluate the performance of the RUNX1 probe in the identification of iAMP21-ALL. This study was a retrospective evaluation of iAMP21-ALL in the Mayo Clinic and Children's Oncology Group cohorts. Of 207 cases of iAMP21-ALL, 188 (91%) were classified as \"typical\" iAMP21-ALL, while 19 (9%) cases were classified as \"unusual\" iAMP21-ALL. The \"unusual\" iAMP21 cases did not meet the current definition of iAMP21 by FISH but were confirmed to have iAMP21 by chromosomal microarray. Half of the \"unusual\" iAMP21-ALL cases had less than five RUNX1 signals, while the remainder had ≥ five RUNX1 signals with some located apart from the abnormal iAMP21-chromosome. Nine percent of iAMP21-ALL cases fail to meet the FISH definition of iAMP21-ALL demonstrating that laboratories are at risk of misidentification of iAMP21-ALL when relying only on the RUNX1 FISH probe. Incorporation of chromosomal microarray testing circumvents these risks.","journal":"Genes Chromosomes and Cancer","year":2022,"id":253565,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":22,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9556,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2022-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":688957,"name":"James B. Smadbeck","orcid":"0000-0002-8902-0950","position":1,"is_corresponding":false},{"id":23898,"name":"Cinthya Zepeda‐Mendoza","orcid":"0000-0002-0434-4965","position":2,"is_corresponding":false},{"id":900152,"name":"Cynthia M. Williamson","orcid":null,"position":3,"is_corresponding":false},{"id":251186,"name":"Beth A. Pitel","orcid":"0000-0002-5138-824X","position":4,"is_corresponding":false},{"id":900153,"name":"Crystal L. Golden","orcid":null,"position":5,"is_corresponding":false},{"id":827689,"name":"Xinjie Xu","orcid":"0000-0001-8373-1834","position":6,"is_corresponding":false},{"id":525261,"name":"Patricia T. Greipp","orcid":"0000-0002-5536-9011","position":7,"is_corresponding":false},{"id":525253,"name":"Rhett P. Ketterling","orcid":"0000-0001-6479-7897","position":8,"is_corresponding":false},{"id":421075,"name":"Nicole L. Hoppman","orcid":null,"position":9,"is_corresponding":false},{"id":525252,"name":"Jess F. Peterson","orcid":"0000-0003-2496-8000","position":10,"is_corresponding":false},{"id":640955,"name":"Christine J. Harrison","orcid":"0000-0002-0526-6794","position":11,"is_corresponding":false},{"id":55018,"name":"Yassmine Akkari","orcid":null,"position":12,"is_corresponding":false},{"id":899511,"name":"Karen D. Tsuchiya","orcid":"0000-0003-1406-5000","position":13,"is_corresponding":false},{"id":899512,"name":"Mary Shago","orcid":"0000-0002-7386-2504","position":14,"is_corresponding":false},{"id":261789,"name":"Linda B. Baughn","orcid":"0000-0001-5229-4897","position":15,"is_corresponding":false},{"id":449118,"name":"Alaa Koleilat","orcid":"0000-0001-7949-7205","position":0,"is_corresponding":true}],"reference_count":29,"raw_metadata":null,"created_at":"2026-07-19T00:24:59.596040Z","pmid":"35771717","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}