%0 Case Reports
%T [Genetic analysis of a case of B-acute lymphoblastic leukaemia with double Philadelphia chromosomes and double derivative chromosome 9s].
%A Zhang X
%A Qin Y
%A Fu Z
%A Zhang B
%A Su M
%A Zhao C
%A Wang C
%J Zhonghua Yi Xue Yi Chuan Xue Za Zhi
%V 40
%N 2
%D Feb 2023 10
%M 36709950
暂无%R 10.3760/cma.j.cn511395-20210527-00447
%X <B>OBJECTIVE: </B>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)].<BR><B>METHODS: </B>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.<BR><B>RESULTS: </B>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%.<BR><B>CONCLUSIONS: </B>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.