IDENTIFICATION OF A COMMONLY DELETED REGION AT 17P13.3 IN LEUKEMIA AND LYMPHOMA ASSOCIATED WITH 17P ABNORMALITY

Fluorescence in situ hybridization (FISH) was performed in 17 myeloid leukemia patients and seven lymphoid leukemia/lymphoma patients who ex hibited chromosomal abnormalities on the short arm of chromosome 17, i n order to detect a commonly deleted region on chromosome band 17p13. Twenty-four leukemia/lymphoma patients studied cytogenetically at our institution over a period of 10 years had detectable 17p abnormalities such as translocation (six patients), addition (11 patients) and dele tion of 17p13 (seven patients). A 17p abnormality was the only abnorma lity present in three patients. Most of the patients had additional co mplex cytogenetic abnormalities. The diagnosis was acute myeloid leuke mia (AML) in 10 patients, two each with chronic myeloid leukemia (CML) , acute lymphoblastic leukemia (ALL), chronic lymphocytic leukemia (CL L) and myelodysplastic syndrome (MDS) and the remaining three with mal ignant lymphoma (RRL). Seven cosmid probes (D17S34, cCl17-624, cCl17-4 53, D17S379, cCl17-636, cCl17-732 and TP53) which mapped on 17p13 were used to analyze the allelic deletion. Eighty percent (19 out of 24) o f the informative leukemia patients exhibited allelic loss in 17p13.3 at cCl7-624, The smallest region of an overlapping deletion was observ ed on chromosome band 17p13.3 between cCl17-624 and cCl17-453. Patient s with transloation involving 17p also showed deletion at cCl17-624 an d cCl17-453. We hypothesize that this region contains a novel tumor su ppressor gene(s) that is involved in leukemogenesis.