Monoallelic p53 deletion in chronic lymphocytic leukemia detected by interphase cytogenetics

Chromosomal aberrations can be defected in 50% of patients with chronic lymphocytic leukemia (CLL). A role for tumor suppressor genes in the genesis of lymphoid tumors has been reported. In B-CLL, p53 gene mutations were found in 10-15% of the patients. We used fluorescence in situ hybridization (FISH) to detect p53 deletion in B-CLL. We also correlated the cytogenetic findings with the clinical course. In situ hybridization to interphase nuclei showed monallelic p53 deletion in 6 of 23 patients (26%). The percentage of cells with one p53 signal ranged from 12 to 100. A statistically significant correlation between p53 deletion and progression of CLL was demonstrated We conclude that FISH is a sensitive and reliable method to defect deletion of specific genes (i.e., p53) in CLL. The finding of p53 deletion is associated with disease progression. (C) Elsevier Science Inc., 1997.