[Significance of PAX5 deletion in childhood B-lineage acute lymphoblastic leukemia without reproducible chromosomal abnormalities].
OBJECTIVE
To identify the incidence of PAX5 deletion in childhood B-lineage acute lymphoblastic leukemia (B-ALL) without reproducible chromosomal abnormalities and to investigate the association between PAX5 abnormalities and prognosis of ALL.


METHODS
Multiplex ligation-dependent probe amplification was used to determine the copy numbers of PAX5 gene in children newly diagnosed with B-ALL without reproducible chromosomal abnormalities between April 2008 and April 2013 and controls (children with non-hematologic diseases or tumors). The patients were classifiied into deletion group and non-deletion group based on the presence of PAX5 deletion.


RESULTS
Eighteen (21%) out of 86 children with B-ALL had PAX5 deletion. The deletion group had a significantly higher total white blood cell count at diagnosis than the non-deletion group (P=0.001). The Kaplan-Meier analysis demonstrated that the deletion group had a significantly lower disease-free survival (DFS) rate than the non-deletion group (0.69±0.12 vs 0.90±0.04; P=0.017), but there was no significant difference in the overall survival rate between the two groups (P=0.128). The Cox analysis showed that PAX5 deletion was a risk factor for DFS (P=0.03).


CONCLUSIONS
PAX5 deletion is an independent risk factor for DFS in B-ALL children without reproducible chromosomal abnormalities.
Diagnostic and Therapeutic Center of Children's Blood Disease, Institute of Hematology and Blood Disease Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300020, China. xfzhu1981@126.com.
Xiao-Ming
XM
Liu
Li
L
Zhang
Min
M
Ruan
Tian-Feng
TF
Liu
Jia-Yuan
JY
Zhang
Fang
F
Liu
Ben-Quan
BQ
Qi
Xiao-Juan
XJ
Chen
Shu-Chun
SC
Wang
Wen-Yu
WY
Yang
Ye
Y
Guo
Yao
Y
Zou
Yu-Mei
YM
Chen
Xiao-Fan
XF
Zhu
D000208:Acute Disease; D000293:Adolescent; D019070:Cell Lineage; D002648:Child; D002675:Child, Preschool; D002869:Chromosome Aberrations; D018572:Disease-Free Survival; D005260:Female; D017353:Gene Deletion; D006801:Humans; D007223:Infant; D008297:Male; D051757:PAX5 Transcription Factor / Q000235:genetics*; D015452:Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics* / Q000401:mortality
D051757:PAX5 Transcription Factor; C497281:PAX5 protein, human