Translocation (6;9;22)(p25;q34;q11.2) identified by FISH in acute leukemia

Fluorescence in situ hybridization (FISH) study of bone marrow cells from a patient with clinically and immunologically acute leukemia showed that an apparent t(6;22)(p25; q11.2) identified by routine banding techniques concealed a complex t(6;9;22)(p25;q34; q11.2). This observation further supports the importance of FISH in those cases where a chromosome rearrangement could not be reliably detected by conventional cytogenetic study.