Fluorescence in situ hybridization for del(5q) in myelodysplasia/acute myeloid leukemia: Comparison of EGR1 vs. CSF1R probes and diagnostic yield over metaphase cytogenetics alone

To determine the clinical utility of FISH for del(5q) in MDS/AML, we first compared FISH for 5q31 (EGR1) and 5q33 (CSF1R) in 51 myeloid neoplasms containing del(5q) by metaphase cytogenetics. Next, EGR1 FISH was compared to metaphase cytogenetics alone in 269 cases of known or suspected MDS/AML. These studies show that while metaphase cytogenetics alone can detect del(5q) in most cases, FISH is particularly useful in cases with suboptimal growth. EGR1 FISH detects del(5q) in a broad variety of myeloid neoplasms, including at least most cases of 5q− syndrome, while studies for CSF1R add little to the diagnostic yield.