Amplification of MLL gene in a new case of acute myeloid leukemia

Sayf Alkatib, Deborah Schloff, Anwar N Mohamed  

Cytogenetics Laboratory, Pathology Department, Wayne State University School of Medicine, Detroit Medical Center, Detroit MI, USA

Previous history

Preleukaemia
-
Malignant disease
-
Inborn condition
-

Clinics case report

Age
75 yrs
Sex
F
Liver
-
Spleen
-
Lymph nodes
-
Cns involv
-

Blood data

Wbc
3.00
Hb
9.0
Platelets
37.000
Blasts
18%
Bone marrow
90 Hypercellular (90%) bone marrow with at least 30% blasts. There was dysplasia in all three cell lines.

Cyto path

Cytology
MDS/AML
Immunophenotype
Flow cytometry identified a population of blasts of myeloid origin encompassing 31% of cells. The blasts were expressing CD13, CD33, CD34, CD117, HLA-DR, and CD56.
Rearranged ig tcr
Not performed.
Pathology
Increased and poorly maturing myeloid leukogenesis. Increased erythrocytogenesis with dysplastic forms (nuclear budding and megaloblastoid changes). Megakaryocytogenesis was markedly increased with dysplastic forms (hypolobulated and multiple widely separated nuclei).
Electron microscopy
Not performed.
Precise diagnosis
Acute myeloid leukemia with multilineage dysplasia.

Survival data

Date diagnosis
09-2009
Treatment
Gemtuzumab Ozogamicin, and 5-Azacitidine.
Complete remission
None
Status
D
Date last follow
11-2009
Survival
2

Karyotype

Sample
Bone marrow aspirate
Culture time
24h without stimulating agents and 48hr with 10% conditioned medium
Banding
GTG.
Results
Analysis of 20 metaphase cells revealed an abnormal female karyotype in all metaphases. Very complex chromosomal abnormalities were identified. karyotype was designated; 45,X,add(X)(q22),-3,del(5)(q13q33),hsr(11)(q23),add(12)(p11.2),-17,+r[cp20].

Other molec studies

Technics
Fluorescence in situ hybridization (FISH) using the LSI EGR1/(5q31)/ D5S23:D5S721 dual color, LSI MLL/11q23 dual color breakapart DNA probes, and whole chromosome paint (WCP) 11 was performed (Vysis Inc. Downers Grove, IL).
Results
Deletion of EGR1/5q31 was seen in 25% of cells and amplification of MLL/11q23 gene was found in 60% of cells. MLL signals appeared fused indicating lack of MLL rearrangement.

Images

Atlas Image
G-banded karyotype showing 45,X,add(X)(q22),-3,del(5)(q13q33), hsr(11)(q23),add(12)(p11.2),-17,+r[cp20].
Atlas Image
FISH with LSI MLL/11q23 probe showing amplification of MLL gene (arrow) along with one normal copy.
Atlas Image
WCP 11 spectrum green on the same metaphase in figure 2 showing two painting signals indicating that the amplified MLL located on chromosome 11 (arrow).

Comments section

Comments
The case described here is of a 75-year-old female who was diagnosed with AML with multilineage dysplasia. Cytogenetics revealed a complex aberrant karyotype (CAK) including deletion of 5q and loss of chromosome 17. In addition, FISH confirmed deletion of EGR1/5q31 and showed amplification of MLL/11q23 gene in the form of hsr at 11q. Literature suggests an association of amplification of MLL with CAK. Moreover, deletions of 5/5q and 17/17p, such as in our case, are frequently found along with MLL amplification. Previously reported AML cases with MLL amplifications tend to occur in elderly patients, and are characterized by rapid progression, poor response to treatment, and poor clinical outcome. The present case supports the notion that MLL amplification is commonly found in the setting of CAK with deletion of chromosome 5 and 17. Thus, the presence of MLL amplification along with deletion 5q in AML cases appears to be a genomic pattern which signifies a poor prognosis in elderly patients.

Article Bibliography

Pubmed IDLast YearTitleAuthors

Citation

Sayf Alkatib, Deborah Schloff, Anwar N Mohamed

Amplification of MLL gene in a new case of acute myeloid leukemia

Atlas Genet Cytogenet Oncol Haematol. 2010-05-01

Online version: http://atlasgeneticsoncology.org/case-report/208843/meetings/favicon/js/web-card-case-report.js