Genetic analysis of a case of B-acute lymphoblastic leukaemia with double Philadelphia chromosomes and double derivative chromosome 9s.
10.3760/cma.j.cn511395-20210527-00447
- Author:
Xuxi ZHANG
1
;
Youwen QIN
;
Zhaoqiang FU
;
Bingyao ZHANG
;
Mengya SU
;
Chuxian ZHAO
;
Chun WANG
Author Information
1. Department of Clinical Laboratory, Shanghai Zhaxin Intergrated Traditional Chinese and Western Medicine Hospital, Shanghai 200436, China. youwenqin@hotmail.com.
- Publication Type:Journal Article
- MeSH:
Humans;
Philadelphia Chromosome;
In Situ Hybridization, Fluorescence/methods*;
China;
Chromosome Aberrations;
Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics*;
Translocation, Genetic;
Fusion Proteins, bcr-abl/genetics*;
Chromosomes, Human, Pair 9/genetics*
- From:
Chinese Journal of Medical Genetics
2023;40(2):242-246
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVE:To explore the genetic basis for a rare case of acute B-lymphocytic leukemia (B-ALL) with double Philadelphia chromosomes (Ph) and double derivative chromosome 9s [der(9)].
METHODS:A patient with double Ph and double der(9) B-ALL who presented at Shanghai Zhaxin Intergrated Traditional Chinese and Western Medicine Hospital in June 2020 was selected as the subject. Bone marrow morphology, flow cytometry, G-banding karyotyping, fluorescence in situ hybridization (FISH), genetic testing and chromosomal microarray analysis (CMA) were used to analyze bone marrow samples from the patient at various stages.
RESULTS:At initial diagnosis, the patient's bone marrow morphology and flow immunotyping have both supported the diagnosis of B-ALL. G-banded karyotyping of the patient indicated double Ph, in addition with hyperdiploid chromosomes involving translocations between chromosomes 9 and 22. BCR-ABL1 fusion gene was positive. Genetic testing at the time of recurrence revealed presence of a heterozyous c.944C>T variant in the kinase region of the ABL1 gene. FISH showed a signal for ABL1-BCR fusion on both chromosome 9s. CMA showed that the mosaicism homozygosity ratio of chromosome 9 was about 40%, and the mosaicism duplication ratio of chromosome 22 was about 43%.
CONCLUSION:Since both der(9) homologs were seen in 40% of cells, the possible mechanism for the double der(9) in this patient may be similar to that of double Ph, which might have resulted from non-disjunction during mitosis in the Ph chromosome-positive cell clone.
