Translocation t(5;6)(q33-34;q23) in an acute myelomonocytic leukemia patient

Adriana Zamecnikova, Soad Al Bahar, Ramesh Pandita Affiliation

Kuwait Cancer Control Center, Department of Hematology, Laboratory of Cancer Genetics, Kuwait

Previous history

Preleukaemia

Malignant disease

Inborn condition

Main items

Clinics case report

Age

68 yrs

Sex

Liver

Spleen

Lymph nodes

Cns involv

Blood data

Wbc

104

7.8

Platelets

Blasts

Bone marrow

Hypercellular marrow with 87% blasts which were PAS diffuse granular positive and SBB (Sudan Black B) positive.

Cyto path

Cytology

Acute myelomonocytic leukemia

Immunophenotype

Positive for CD13, CD15, CD117, CD33, MPO, CD45, HLDR and dim CD34 (27%)

Precise diagnosis

Acute myelomonocytic leukemia

Survival data

Date diagnosis

03-2013

Treatment

Chemotherapy (Daunorubicin & Cytarabine combination therapy; consolidation with high dose Ara-C)

Complete remission

Treatment relat death

Relapse

Phenotype relapse

Acute myelomonocytic leukemia

Status

Date last follow

11-2013

Survival

Karyotype

Sample

Bone marrow, blood

Culture time

Banding

G-banding

Results

46,XX,t(5;6)(q33-34;q23)[25]

Karyotype relapse

46,XX,t(5;6)(q33-34;q23)[1]/46,XX,t(5;6)(q33-34;q23),t(7;10)(p22;q23)[19]

Mol cytogenet technics

Fluorescence in situ hybridization (FISH) with LSI AML1-ETO, LSI MLL, LSI CBFB/inv(16), LSI EGRI/5q31 (Abbott Molecular, Downers Grove, IL) and XL 6q21/6q23, XL PDGFR, whole chromosome 6 probe Metasystem, Germany).

Mol cytogenet results

Normal signal patterns for LSI AML1-ETO, LSI MLL, LSI CBFB/inv(16), LSI EGRI/5q31, XL 6q21/6q23 and XL PDGFR probes.

Images

Figure 1. A. Karyotype from the time of diagnosis showing the chromosomal translocation t(5;6)(q33-34;q23). B. Fluorescence in situ hybridization studies (FISH) with XL 6q21/6q23 (Metasystem, Germany) probe showing red and green signals on both, normal and der(6) chromosomes. C. Applying the XL PDGFR probe (Metasystem, Germany) showed normal signal pattern on both normal and der(5) chromosomes, indicating that PDGFR located on 5q32-33 is not involved in the translocation. D. Hybridization with whole chromosome 6 probe (Metasystem, Germany) showing translocation of chromosome 6 sequences to der(5) chromosome.

Figure 2. A. Karyotype from blood cell from the time of relapse showing the t(5;6)(q33-34;q23) and a new anomaly t(7;10)(p22;q23). B. Partial karyotypes from blood and bone marrow showing the t(5;6)(q33-34;q23).

Comments section

Comments

Chromosomal translocations involving 5q33 and 6q23 have been reported in only one patient with T-ALL and an associated myeloproliferative neoplasm and C6ORF204/PDGFRB fusion (Chmielecki et al 2012). While in this case, the chromosomal translocation appeared to be morphologically identical to our t(5;6)(q33-34;q23), in our patient PDGFRB (5q32-33) is not rearranged and MYB (6q23)is not translocated to chromosome 5 as in a previously described case. Due to the availability of tyrosine kinase inhibitors for PDGFRB rearranged disorders, our findings emphasize the importance of FISH in precise characterizing of chromosome rearrangements with 5q33-34 breakpoints, especially in suboptimal preparations.

Bibliography

Pubmed ID	Last Year	Title	Authors
21938754	2012	Systematic screen for tyrosine kinase rearrangements identifies a novel C6orf204-PDGFRB fusion in a patient with recurrent T-ALL and an associated myeloproliferative neoplasm.	Chmielecki J et al

Citation

Adriana Zamecnikova, Soad Al Bahar, Ramesh Pandita

Translocation t(5;6)(q33-34;q23) in an acute myelomonocytic leukemia patient

Atlas Genet Cytogenet Oncol Haematol. 2014-02-01

Online version: http://atlasgeneticsoncology.org/case-report/208874/translocation-t(5;6)(q33-34;q23)-in-an-acute-myelomonocytic-leukemia-patient