[Combination of interphase- and metaphase-fluorescence in situ hybridization to identify 11q23/MLL abnormalities in acute leukemia patients].
OBJECTIVE
To explore a rapid, sensitive and effective method for identifying 11 q23/MLL gene rearrangements and investigate the incidence and clinical features of adult acute leukemia (AL) patients with 11 q23/MLL abnormalities.


METHODS
Bone marrow samples from 112 adult AL patients were prepared by short-term (24 hours) unstimulated culture, and karyotyped by R-banding. The abnormal signals were screened by interphase- fluorescence in situ hybridization (FISH) with dual-color break-apart 11 q23/MLL-specific probe, and the 11 q23/MLL gene rearrangements were determined by metaphase-FISH.


RESULTS
Of the 112 patients,9 (8. 0%) with 11q23/MLL translocations were revealed by FISH, among which only 4 (3. 6% ) was revealed by CCA. Three patients were reported by CCA to have del( 11) ( q23) , while by FISH assay two of them were 11 q23/MLL translocation and one was true deletion of I lq23 telomeric terminus. Furthermore by FISH assay II q23/MLL translocations were identified in one each patient with normal karyotype, with 11 q + and without overt 11 q23 abnormality. Eight patients with MLL gene amplification including polysome, homogenous staining region (hsr) and double minute chromosome (dmin) were also disclosed by FISH. AL patients with 11 q23/MLL abnormalities were frequently diagnosed as pro-B acute lymphoblastic leukemia (pro-B ALL) ,acute monocytic leukemia (AMoL) or biphenotypic acute leukemia (BAL).


CONCLUSIONS
FISH with dual-color break-apart I q23/MLL -specific probe is a rapid and sensitive method to detect 11 q23/MLL abnormalities, as compared with CCA. FISH also effectively discloses translocations and amplifications involving 11 q23/MLL,and should be performed in patients diagnosed as pro-B ALL,AMoL or BAL, with CCA normal karyotype.
Zhao
Xi-chen
XC
Institute of Hematology and Blood Diseases Hospital, CAMS & PUMC, Tianjin 300020, China.
Li
Cheng-wen
CW
Dai
Yun
Y
Liu
Xu-ping
XP
Qin
Shuang
S
Liu
Shi-he
SH
Mi
Ying-chang
YC
Wang
Jian-xiang
JX
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002872:Chromosome Deletion; D002880:Chromosomes, Human, Pair 11 / Q000235:genetics*; D005260:Female; D015321:Gene Rearrangement; D011495:Histone-Lysine N-Methyltransferase; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D007399:Interphase / Q000235:genetics; D007938:Leukemia / Q000235:genetics*; D008297:Male; D008677:Metaphase / Q000235:genetics; D008875:Middle Aged; D051788:Myeloid-Lymphoid Leukemia Protein / Q000235:genetics*; D014178:Translocation, Genetic
C497422:KMT2A protein, human; D051788:Myeloid-Lymphoid Leukemia Protein; D011495:Histone-Lysine N-Methyltransferase