CASE REPORTS in HAEMATOLOGY (Paper co-edited with the European LeukemiaNet)

Translocation t(7;9)(q34;q32) found in pediatric T-cell Acute Lymphoblastic Leukemia

Clinics

Age and sex :	4 year(s) old female patient.
Previous History :	no preleukemia
	no previous malignant disease
	no inborn condition of note
Organomegaly :	hepatomegaly ; splenomegaly ; enlarged lymph nodes ; no central nervous system involvement

Blood

WBC : 148 x 109/l; Hb : 9.8 g/dl; platelets : 13 x 109/l;

Bone marrow : 100%

Cyto pathology classification

Cytology : L2

Immunophenotype : NK+, CD2, CD3, CD4, CD5, CD7, CD8, and TdT+

Precise diagnosis : Acute Lymphoblastic Leukemia, L2

Survival

Date of diagnosis: 02-2006

Treatment : chemotherapy (intrathecal and systemic), cranial X-ray therapy, and allogenic stem cell transplant

Relapse : + central nervous system (8/06 with cytogenetics) and bone marrow relapse

Status : Alive 08-2007

Survival : 31 month(s)

Karyotype

Sample : diagnostic sample was of bone marrow ; culture time : analysis of diagnostic sample was performed on overnight colcemid, 18-hour and 72-hour cultures ; banding : 350 band level

Results : 46,XX,t(7;9)(q34;q31~q32)[16]/46,XX[4]

Karyotype at relapse : Date: 08-2006; Result: 46,XX,del(6)(q21),t(7;9)(q34;q31~q32)[cp2]/46,XX[19]

Partial karyotypes of metaphases from diagnostic sample overnight colcemid culture.

Comments

The patient presented in this case report has features consistent with other reported cases of T cell acute lymphoblastic leukemia (T-ALL) with t(7;9)(q34;q32) involving the TCRbeta locus on 7q34 and the TAL2 gene on 9q34. In particular, review of the literature revealed a case in a 3 year old male with similar clinical and hematological findings and the same additional cytogenetic anomaly, del(6)(q21). Approximately 60% of clinically normal individuals have t(7;9)(q34;q32) created by V(D)J recombination which uses a fortuitous recombination site (RSS) located 3'of the TAL2 oncogene. In T-ALL affected individuals a rare second rearrangement occurs between the junction point of the original t(7;9) and Jbeta2. This brings the TAL2 gene under the control of TCRbeta enhancer, and leads to its' inappropriate expression.

Internal links

Atlas Card

t(7;9)(q34;q32)

Bibliography

Clinical and biologic characterization of T-cell neoplasias with rearrangements of chromosome 7 band q34.

Smith SD, Morgan R, Gemmell R, Amylon MD, Link MP, Linker C, Hecht BK, Warnke R, Glader BE, Hecht F

Blood. 1988 ; 71 (2) : 395-402.

PMID 2962650

Distinct t(7;9)(q34;q32) breakpoints in healthy individuals and individuals with T-ALL.

Marculescu R, Vanura K, Le T, Simon P, Jˆ§ger U, Nadel B

Nature genetics. 2003 ; 33 (3) : 342-344.

PMID 12567187

Contributor(s)

Written	09-2007	Jennifer JS Laffin, Randee J Blumer, Sara J Morrison-Delap, Elizabeth A Rauch, Eric B Johnson, Carol A Diamond, Kate J Thompson, Gordana Raca, Karen D Montgomery, Daniel F Kurtycz
		University of Wisconsin-Madison, School of Medicine and Public Health, Department of Pediatrics, University of Wisconsin Cytogenetic Services, Wisconsin State Laboratory of Hygiene, Madison, WI, USA (JJSL)(CAD); University of Wisconsin Cytogenetic Services, Wisconsin State Laboratory of Hygiene, Madison, WI, USA (RJB)(SJMD)(EAR)(EBJ)(KJT); University of Wisconsin-Madison, School of Medicine and Public Health, Department of Pathology and Laboratory Medicine, University of Wisconsin Cytogenetic Services, Wisconsin State Laboratory of Hygiene, Madison, WI, USA (GR)(KDM)(DFK)

Citation

This paper should be referenced as such :

Laffin JJS, Blumer RJ, Morrison-Delap SJ, Rauch EA, Johnson EB, Diamond CA, Thompson KJ, Raca G, Montgomery KD, Kurtycz DF . . Atlas Genet Cytogenet Oncol Haematol. Septem ber 2007 . URL : http://AtlasGeneticsOncology.org/Genes/0709LaffinID100032.html

This paper is referenced by INIST as such :

© Atlas of Genetics and Cytogenetics in Oncology and Haematology

indexed on : Sat Mar 9 12:39:48 CET 2013

For comments and suggestions or contributions, please contact us