Chromosomal translocation t(X;11)(q22;q23) involving the MLL gene

2011-09-01  Adriana Zamecnikova, Soad Al Bahar, Hassan A Al Jafar, Rames Pandita

Kuwait Cancer Control Center, Dep of Hematology, Laboratory of Cancer Genetics, Kuwait (AZ, SAB, RP); Dep of Hematology, Amiri Hospital, Kuwait (HAAJ)

Previous history

Preleukaemia
-
Malignant disease
-
Inborn condition
-

Clinics case report

Age
15 mths
Sex
M
Liver
-
Spleen
-
Lymph nodes
-
Cns involv
-

Blood data

Wbc
50.2 (neutrophils 2%, lymphocytes 68%, probably blasts, monocytes 16%, atypical lymphocytes 14% undifferenciated cells)
Hb
10.2
Platelets
191
Blasts
14
Bone marrow
The bone marrow was hypercellular with more than 50% blasts that were positive for CD45, CD33, CD15, CD13, CD14 and HLA-DR.

Cyto path

Cytology
AML M4
Immunophenotype
M4. CD13+,CD14+, CD15+, CD33+, CD45+, CD64+ and MPO.
Precise diagnosis
Acute myelomonocytic leukemia

Survival data

Date diagnosis
02-2010
Treatment
Chemotherapy (ADE)
Complete remission
+
Treatment relat death
-
Relapse
-
Status
A
Date last follow
02-2011
Survival
12

Karyotype

Sample
BM
Culture time
24
Banding
G-band
Karyotype relapse
46,XY [5] / 46,Y,t(X;11)(q22;q23) [25]
Mol cytogenet technics
Fluorescence in situ hybridization.
Mol cytogenet results
MLL rearrangement was identified using the LSI MLL (11q23) Dual Color Break Apart Rearrangement probe (Abbott Molecular) revealing 80% of cells with MLL rearrangement. The rearrangement was confirmed in metaphases demonstrating that the distal part of the MLL gene was juxtaposed to the der(X) chromosome.

Images

Atlas Image
Top: partial karyotype of the patient. Bottom: fluorescence in situ studies were performed successively on G-banded slides prepared for chromosome analysis using a locus-specific, break-apart probe for MLL (green and red signals) and with centromeric X/Y probe (Vysis) (red and green signal). Hybridization on metaphase cells with the MLL probe detected one MLL signal on the normal chromosome 11 (red-green fusion signal) and signals on the der(11) (green signal) and the der(X), confirming MLL disruption. The red signal from MLL has moved to the derivative chromosome X, indicating that the breakpoint is in the 5 of the MLL gene. Arrows indicate derivative chromosomes, arrow heads are pointing to derivative chromosomes X and 11.

Comments section

Comments
As the gene in Xq22 is yet unknown, it is therefore uncertain whether this translocation involve a new MLL partner. Due to the similar clinical features with patients with t(X;11)(q13;q23) involving the FOXO4/MLL genes, (such as occurrence in infants and young children diagnosed with acute myelomonocytic leukemia), the possibility of involvement of FOXO4 or FOXO related gene in our patient cannot be excluded. In addition as MLL rearrangements are frequently confirmed in cases with highly complex changes, complex and/or cryptic changes cannot be excluded.

Article Bibliography

Pubmed IDLast YearTitleAuthors
95932861998Ten novel 11q23 chromosomal partner sites. European 11q23 Workshop participants.Harrison CJ et al
82201281993Acute megakaryoblastic leukemia in children and adolescents: a retrospective analysis of 24 cases.Ribeiro RC et al
186336152008The application of conventional cytogenetics, FISH, and RT-PCR to detect genetic changes in 70 children with ALL.Soszynska K et al

Citation

Adriana Zamecnikova, Soad Al Bahar, Hassan A Al Jafar, Rames Pandita

Chromosomal translocation t(X;11)(q22;q23) involving the MLL gene

Atlas Genet Cytogenet Oncol Haematol. 2011-09-01

Online version: http://atlasgeneticsoncology.org/case-report/208854/chromosome-explorer/new-content/teaching-explorer/submit-meetings/