Subiocalization of the chromosome 5 breakpoint of the 3;5 translocation in myelodysplastic syndromes and acute myeloid leukemia

✍ Scribed by Dr. Stephan W. Morris; John T. Foust; Marcus B. Valentine; W. Mark Roberts; David N. Shapiro; A. Thomas Look

• Publisher: John Wiley and Sons
• Year: 1992
• Tongue: English
• Weight: 688 KB
• Volume: 5
• Category: Article
• ISSN: 1045-2257
• DOI: 10.1002/gcc.2870050414

✦ Synopsis

A t(3;5)(q25. I ;q34) reciprocal translocation identifies a subset of cases of myelodysplastic syndrome o r acute myeloid leukemia (AML) that are characterized by increased numbers of megakaryocytes and severe trilineage dysplasia. As a first step in characterizing the t(3;5) breakpoints, we asked whether the translocation involves the CSFl RIPDGFRB locus at 5q33-q35.

Pulsed-field gel electrophoretic analysis of a region extending 580 kb 5' to the PDGFRB gene and I20 kb 3' to the CSFl R gene did not reveal aberrant restriction fragments in leukemic cell DNA, confirming that the breakpoint does not occur in the vicinity of thesegenes. T o sublocalize the breakpoint, we performed Southern blot hybridizations using DNAfrom human x hamster somatic cell hybrids containing the normal 3, the normal 5, the derivative 3, or the derivative 5 human chromosome. Using a series of polymorphic D N A probes from the long arm of chromosome 5, which have been linked by genetic recombination, we bracketed the breakpoint t o within a region that spans%' I 3 centimorgans (sex average) and is flanked by the q34-qter markers cKK5. I9 and L I200 (D5S62). This analysis places the chromosome 5 breakpoint of the t(3;5) considerably telomeric to the CSFIRIPDGFRB locus, confirming our studies with pulsed-field electrophoresis. Future efforts to identify the genes affected by the t(3;S) should focus on the 5q segment described in this study. Genes Chrom Cancer 5:385-391 (1992).