FLT4 RECEPTOR TYROSINE KINASE GENE-MAPPING TO CHROMOSOME BAND 5Q35 INRELATION TO THE T(2 5), T(5 6), AND T(3 5) TRANSLOCATIONS

FLT4 is a recently cloned receptor tyrosine kinase cDNA, which is char acterized by seven immunoglobulin-like loops in its extracellular doma in. We have previously mapped the FLT4 gene to chromosome segment 5q33 -qter using somatic cell hybrids. Here we have refined the localizatio n to band 5q35 by fluorescence in situ hybridization and show that the gene is translocated to chromosomes 2 and 6 in the t(2;5)(p23;q35) an d t(5;6)(q35;p21) translocations, respectively, of Ki-1-positive lymph omas, as well as to chromosome 3 in the t(3;5)(q25.1;q34) translocatio n, which is occasionally found in myelodysplastic syndromes and acute myeloid leukemia. No evidence was obtained for a rearrangement or dere gulation of the translocated FLT4 gene. We further show that abundant FLT4 mRNA expression occurs only in erythroid and megakaryoblastoid ce ll lines among nine leukemia cell lines studied. (C) 1993 Wiley-Liss, Inc.