Molecular analysis of six variant Philadelphia chromosome translocations in chronic myeloid leukemia

Mario Sessarego, Giovanni Martinelli, Andrea Chiamenti, Raffaella Defferrari, Giuseppina Fugazza, Roberto Bruzzone, Franco Ajmar, Pier Franco Pignatti

Research output: Contribution to journalArticle

Abstract

In 420 Philadelphia positive (Ph+) chronic myeloid leukemia (CML) patients karyotyped at diagnosis in our laboratory, 26 Ph variants (6.2%) were observed. Twelve of them are reported. Five cases are "simple" variants without detectable involvement of band 9q34, and seven are "complex," since a third chromosomal band is involved in the Ph formation. Two translocations [t(7;22)(q36;q11) and t(9;22;12)(q34;q11;q11)] are reported for the first time. Six cases were characterized molecularly, and bcr-abl rearrangement was demonstrated, confirming involvement of 9q34 band also in the cases in which chromosomes 9 appear cytogenically normal. Chimeric mRNAs in which M-BCR exon 3 is joined to abl exon 2 (type b3-a2) were detected in four of six cases; one case showed a DNA breakpoint in zone III, which may also give rise to the same transcript. In one case, mRNA junction was b2-a2. The frequency of the b3-a2 junction occurs more frequently in CML patients with a Ph variant than in patients with the standard translocation, suggesting a preferential correlation between this type of transcript and the involvement of other chromosomes in Ph formation.

Original languageEnglish
Pages (from-to)50-54
Number of pages5
JournalCancer Genetics and Cytogenetics
Volume67
Issue number1
DOIs
Publication statusPublished - 1993

ASJC Scopus subject areas

  • Cancer Research
  • Genetics
  • Molecular Biology

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  • Cite this

    Sessarego, M., Martinelli, G., Chiamenti, A., Defferrari, R., Fugazza, G., Bruzzone, R., Ajmar, F., & Pignatti, P. F. (1993). Molecular analysis of six variant Philadelphia chromosome translocations in chronic myeloid leukemia. Cancer Genetics and Cytogenetics, 67(1), 50-54. https://doi.org/10.1016/0165-4608(93)90043-L