Oligonucleotide Array-based Comparative Genomic Hybridization Approach in Hematologic Malignancies With Normal/Failed Conventional Cytogenetics and Fluorescent In Situ Hybridization

Oligonucleotide array-based comparative genomic hybridization (oaCGH) was used to investigate 60 cases of hematologic malignancies, mainly acute myeloid leukemias and myelodysplastic syndromes, in order to evaluate its sensitivity and specificity and to search for genomic alterations undetected by previous investigation with conventional cytogenetics (CC) and fluorescent in situ hybridization (FISH). On the basis of CC and FISH results, we subdivided the series into group A (36 cases with a normal karyotype after CC and/or FISH testing) and group B (24 cases with anomalies detected by CC and/or FISH). oaCGH did not show alterations in 21 cases of the group A (58.3%); in the remaining 15 cases (41.7%), it detected 19 new abnormalities (14 amplifications and 5 deletions). In the group B, oaCGH confirmed 32/55 aneuploidies detected by FISH (58.1%). The sensitivity increased at 27/33 confirmed aneuploidies (81.8%) by placing as a cutoff a mosaic of 50%. Moreover, in the cases of this group oaCGH revealed 36 new alterations (15 amplifications and 21 deletions). From these results it is possible to assess a strong overlap between results obtained by FISH and oaCGH. However, oaCGH is a reliable alternative where CC and FISH are not feasible and is able to identify new alterations unexplored by FISH