Korean J Lab Med.  2002 Dec;22(6):373-381.

Clinical Implication of the Deletion Status of ABL-BCR on Derivative Chromosome 9 in Chronic Myelogenous Leukemia

• Lee YK
• Kim YR
• Lee DS
• She CJ
• Yoon SS
• Park SY
• Kim BK
• Cho HI

Abstract

BACKGROUND: The complementary ABL-BCR gene rearrangement is formed at chromosome 9 parallel to the Ph chromosome at der(22)t(9;22), which has been found deleted in a minority of chronic myelogenous leukemia (CML) patients. This study was designed to analyze the deletion status of ABL and/or BCR on derivative chromosome 9 and to evaluate the prognostic significance of the deletion of these genes in CML.
METHODS
We studied 79 patients who were diagnosed as CML at Seoul National University Hospital between January 1997 and February 2002. The deletion status of ABL and BCR on derivative chromosome 9 was investigated by interphase fluorescent in situ hybridization (FISH) method.
RESULTS
ABL deletion was detected in 14 (17.7%) patients and BCR deletion was observed in 8 patients (10.1%). Event-free survival time of the patients with ABL and/or BCR deletion (19.0%) was shorter than that of the patients without any deletion of these two genes (median, 40.0 months vs. 92.0 months)(P=0.027). Twenty seven patients progressed to blast crisis in this period. The period to blast crisis was also shorter in 8 patients with ABL and/or BCR deletion than in 19 patients without any gene deletion (P=0.044). The b2a2 mRNA type was more frequent in the patients with ABL deletion only than in the patients without any gene deletion (P=0.034).
CONCLUSIONS
Event-free survival time and the period to blast crisis were significantly shorter in patients with deletion of ABL and/or BCR on derivative chromosome 9. ABL and/or BCR deletion can be a significant prognostic marker that indicates rapid disease progression.

Keyword

Chronic myelogenous leukemia; CML; Philadelphia chromosome; Fluorescence in situ hybridization; FISH; ABL deletion; BCR deletion; derivative chromosome 9

MeSH Terms

Blast Crisis
Chromosomes, Human, Pair 9*
Disease Progression
Disease-Free Survival
Gene Deletion
Gene Rearrangement
Humans
Hydrogen-Ion Concentration
In Situ Hybridization, Fluorescence
Interphase
Leukemia, Myelogenous, Chronic, BCR-ABL Positive*
Philadelphia Chromosome
RNA, Messenger
Seoul
RNA, Messenger