Deletion of chromosome band 13q14: a primary event in preleukemia and leukemia.

Chromosome abnormalities were analyzed in 200 consecutive patients with preleukemia and leukemia, and four patients were found with a deletion of 13q14 for an incidence of 2%. Together with data on chromosome aberrations in cancer from the literature, our results indicate clearly that deletion of band 13q14 is a nonrandom chromosome anomaly in premalignant and malignant blood disorders. Deletion of 13q14 appears specifically to constitute a primary event in the initiation of preleukemia. An additional rearrangement involving another chromosome must occur for progression of the preleukemia to acute nonlymphocytic leukemia.