A pediatric case of acute lymphoblastic leukemia with t(2;9)(q12;q34) (RANBP2/ABL1 fusion)

S Marc De Braekeleer, Nadia Guéganic, Alexandra Schifferli, Joëlle Tchinda. Affiliation

Cytogenetics Laboratory, Faculty of Medicine, University of Brest, France marc.debraekeleer@univ-brest.fr (MdeB, NG)) Department of Hematology/Oncology, University Children s Hospital Basel, Switzerland (AS) University Children s Hospital Zurich, Switzerland (JT).

Previous history

Preleukaemia

Malignant disease

Inborn condition

Clinics case report

Age

21 mths

Sex

Liver

Spleen

Lymph nodes

Cns involv

-t

Blood data

Wbc

77.5 (N: 6-17.5)

29 (N: 105-135)

Platelets

69 (N: 150-450)

Blasts

Bone marrow

Hypercellular marrow, with 93.7% blasts (small to middle-sized cells with large nucleus and minimal cytoplasm).

Cyto path

Phenotype

Pre-B acute lymphoblastic leukemia.

Immunophenotype

cTDT, cCD79a, cIgM, CD19 and CD20 positive.

Rearranged ig tcr

not performed.

Precise diagnosis

Pre-B acute lymphoblastic leukemia.

Survival data

Date diagnosis

01-2014

Treatment

Protocol AIEOP-BFM ALL 2009 high risk.

Complete remission

Treatment relat death

Relapse

Status

Date last follow

12-2015

Survival

23 +

Karyotype

Sample

bone marrow.

Banding

G banding.

Results

46,XX,t(2;9)(q12-14;q34),add(5)(p14)[5]/46,sl,-7,+mar[2]/46,XX[3]

Karyotype relapse

not applicable.

Mol cytogenet technics

FISH experiments with BAC clones located in bands 2q12.1 to 2q14.2.

Mol cytogenet results

A split signal on der(2) and der(9) was found with RP11-622D1, RP11-347H10, RP11-259O12, RP11-348G16 and RP11-953L12. These BAC clones overlap the RANBP2 gene and allow refinement of the breakpoint to a 25kb region covering the 5 end and the first three exons of RANBP2.

Other molec studies

Technics

MLPA.

Results

Negative.

Images

GTG banding showing chromosomes 2 and 9 and the derivatives der(2) and der(9).

FISH with BACs RP11-953L12 (spectrum green, located in 2q12 and containing RANBP2) and RP11-83J21 (spectrum orange, located in 9q34 and containing the 3 part of ABL1) and CEP9 (in aqua) showing one fusion signal on der(2). No fusion is detected on der(9) because RP11-83J21 does not cover the 5 part of ABL1.

Comments section

Comments

We present here a unique case of pediatric acute lymphoblastic leukemia. This fusion gene was identified in another case by RNA-sequencing (Roberts et al., 2012).

Bibliography

Pubmed ID	Last Year	Title	Authors
22897847	2012	Genetic alterations activating kinase and cytokine receptor signaling in high-risk acute lymphoblastic leukemia.	Roberts KG et al

Citation

S Marc De Braekeleer, Nadia Guéganic, Alexandra Schifferli, Joëlle Tchinda.

A pediatric case of acute lymphoblastic leukemia with t(2;9)(q12;q34) (RANBP2/ABL1 fusion)

Atlas Genet Cytogenet Oncol Haematol. 2015-12-01

Online version: http://atlasgeneticsoncology.org/case-report/208882/a-pediatric-case-of-acute-lymphoblastic-leukemia-with-t(2;9)(q12;q34)-(ranbp2-abl1-fusion)