[Deletions and rearrangements of PAX5 gene in B-lineage acute lymphoblastic leukemia].

OBJECTIVE

To determine the frequency paired-box domain 5 (PAX5) gene alterations in B-lineage acute lymphoblastic leukemia (B-ALL) harboring 9p abnormalities and its implication for clinical prognosis.

METHODS

Bacterial artificial chromosomes RP11-344B23 and RP11-652D9 encompassing the PAX5 gene were selected. DNA was extracted with conventional method and labeled with fluorescein by nicking transition. Fluorescence in situ hybridization (FISH) was used to determine the rearrangement or deletion of the PAX5 gene in B-ALL harboring chromosome 9p abnormalities. Clinical and laboratory features of patients were analyzed.

RESULTS

Fifty cases were analyzed with FISH. Complete deletion was observed in 23 patients (46%), partial deletion was observed in 2 patients (4%), and rearrangement was detected only in 1 case. The total frequency of abnormalities was 52% (26/50). No significant difference was found in clinical features of patients with or without PAX5 rearrangement or deletion.

CONCLUSION

The frequency of PAX5 gene alterations in B-ALL harboring 9p abnormalities was 52%. However, no significant difference was found between patients with and without PAX5 alterations.