Affordable Access

Formation of der(19)t(1;19)(q23;p13) in acute lymphoblastic leukemia.

Wiley-Liss, Inc.
Publication Date
  • Medicine And Health Sciences


The t(1;19)(q23;p13), which results in a fusion of TCF3 (previously E2A) at 19p13 with PBX1 at 1q23, is one of the most common translocations in acute lymphoblastic leukemia (ALL). It is seen either as a balanced t(1;19) or as an unbalanced der(19)t(1;19); occasional cases with coexisting t(1;19)- and der(19)-positive clones also have been described. Although it generally has been assumed that the unbalanced form arises from the balanced t(1;19) through loss of the derivative chromosome 1 followed by duplication of the normal homologue, this has never been proved. At least two other mechanisms are possible for the formation of the der(19): an initial trisomy 1 followed by translocation and subsequent loss of the der(1) or a rearrangement during the G2 phase of the cell cycle, with the derivative chromosomes 1 and 19 ending up in separate daughter cells. The different alternatives may be distinguished by investigation of markers proximal to the breakpoint in 1q23 because they would be expected to lead to different allelic patterns. Thus, loss of heterozygosity as a result of the presence of uniparental disomy (UPD) both copies of a chromosome being derived from only one parent-for chromosome 1 would be present in all der(19)-harboring cases arising via the duplication pathway and in one-third of cases arising via the trisomy pathway, but in none of the der(19) formed via the G2 pathway. In this study, we used quantitative fluorescence PCR with polymorphic microsatellite markers to investigate chromosomes 1 and 19 in two t(1;19)- and four der(19)-positive ALLs. None of the der(l cases displayed UPD for chromosome 1, excluding that this aberration arises through the duplication pathway. Because previous findings of cases with coexisting t(1;19) and der(19) clones are difficult to explain if the translocation originated in G2, the present results suggest that an unbalanced der(19) may arise from an initial trisomy 1 followed by t(1;19) translocation and loss of the derivative chromosome 1.

There are no comments yet on this publication. Be the first to share your thoughts.


Seen <100 times

More articles like this

Formation of der(19)t(1;19)(q23;p13) in acute lymp...

on Genes Chromosomes and Cancer February 2005

A case of adult B lymphoblastic leukemia with ider...

on The Korean journal of laborato... December 2010

Acute lymphoblastic leukemia associated with a t(1...

on Internal medicine (Tokyo, Japa... July 1993
More articles like this..