t(4;22)(q12;q11.2)

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t(4;22)(q12;q11.2)

Identity

Partial karyotype showing chromosomes 4 and 22.

Clinics and Pathology

Disease Reported in 3 cases; myeloproliferative disorder : atypical chronic myeloid leukemia (aCML) (Philadelphia chromosome-negative) .

Etiology One case was post-treatment for lymphoma, thus suspected to be a secondary MPD.

Clinics 3 cases shared characteristics of splenic enlargement, eosinophilia and male predominance.

Peripheral blood smear showing anemia, leukocytosis with increased granulocytes and precursors, and eosinophilia. Bone marrow showing hypercellularity with marked myeloid hyperplasia, mild eosinophilia, no increase in blasts.

Prognosis One patient on treatment with good response to imatinib mesylate.

Cytogenetics

Note t(4;22)(q12;q11.2), easily distinguished cytogenetically.

Cytogenetics Molecular FISH for BCR- ABL1 is negative for fusion but will show extra signal for BCR when using the dual fusion probe set. BCR-ABL1 PCR is negative.

Interphase FISH showing 3 signals for BCR (green), suggesting rearrangement. Two normal signals for ABL1 (red).

Probes BCR-ABL dual fusion probe set.

Additional anomalies The t(4;22) was observed as the sole anomaly in the few reported cases to date.

Genes involved and Proteins

Gene Name PDGFRA

Location 4q12

Note Member of the protein-tyrosine kinase receptor family subclass III that includes the colony stimulating factor-1, c-KIT, FLT1, and FLT3/FLK2. Suggested role for normal PDGFRA receptor expression during periods of glial cell development and connective tissue growth.

Dna / Rna 23 exons; includes 2 intracellular tyrosine kinase domains, TK1 and TK2 (exons 13-15 and 17-21), 5 extracellular Ig-like domains (exons 3-10), and a hydrophobic transmembrane domain (exon 10). The cytoplasmic region also encodes an ATP binding site.

Protein 170-kD transmembrane glycoprotein that normally binds all PDGF isoforms, AA, AB, and BB at its extracellular Ig domain.

Gene Name BCR

Location 22q11.2

Dna / Rna 23 exons; alternate splicing.

Protein 160-kDa protein; contains a unique serine/threonine kinase activity and at least two SH2 binding sites encoded in its first exon and a C-terminal domain that functions as a GTPase activating protein for p21(rac).

Result of the chromosomal anomaly

Hybrid gene
Note 5'BCR-3'PDGFRA fusion

Description Fusion of BCR exon 7, 12 or 17 (in 3 cases described) with PDGFRA exon 12, in frame, containing intronic sequence from BCR in two cases.

Fusion Protein
Description 169 kDa protein in one case, somewhat smaller in two others.

Expression Localisation Predicted to be localized intracellularly

Oncogenesis Alteration of tyrosine kinase activity secondary to loss of regulatory and PDGF binding domains; also, BCR domains may significantly affect BCR-PDGFRA downstream signaling pathways as seen with BCR-ABL fusion.

External links

Other database t(4;22)(q12;q11.2) Mitelman database (CGAP - NCBI)

Other database t(4;22)(q12;q11.2) CancerChromosomes (NCBI)

Other database	t(4;22)(q12;q11.2)	Mitelman database (CGAP - NCBI)
Other database	t(4;22)(q12;q11.2)	CancerChromosomes (NCBI)

Bibliography

Identification and structural analysis of the A type receptor for platelet-derived growth factor. Similarities with the B type receptor.

Claesson-Welsh L, Hammacher A, Westermark B, Heldin CH, Nistˆ©r M

The Journal of biological chemistry. 1989 ; 264 (3) : 1742-1747.

PMID 2536372

Structure, organization, and transcription units of the human alpha-platelet-derived growth factor receptor gene, PDGFRA.

Kawagishi J, Kumabe T, Yoshimoto T, Yamamoto T

Genomics. 1995 ; 30 (2) : 224-232.

PMID 8586421

Functional importance of platelet-derived growth factor (PDGF) receptor extracellular immunoglobulin-like domains. Identification of PDGF binding site and neutralizing monoclonal antibodies.

Lokker NA, O'Hare JP, Barsoumian A, Tomlinson JE, Ramakrishnan V, Fretto LJ, Giese NA

The Journal of biological chemistry. 1997 ; 272 (52) : 33037-33044.

PMID 9407086

A FISH study of variant Philadelphia rearrangements.

Reddy KS, Sulcova V

Cancer genetics and cytogenetics. 2000 ; 118 (2) : 121-131.

PMID 10748292

The t(4;22)(q12;q11) in atypical chronic myeloid leukaemia fuses BCR to PDGFRA.

Baxter EJ, Hochhaus A, Bolufer P, Reiter A, Fernandez JM, Senent L, Cervera J, Moscardo F, Sanz MA, Cross NC

Human molecular genetics. 2002 ; 11 (12) : 1391-1397.

PMID 12023981

CML after treatment for lymphoid malignancy: Therapy-related CML or coincidence?

Bolaˆ±os-Meade J, Sarkodee-Adoo C, Khanwani SL

American journal of hematology. 2002 ; 71 (2) : page 139.

PMID 12353319

Novel translocations that disrupt the platelet-derived growth factor receptor beta (PDGFRB) gene in BCR-ABL-negative chronic myeloproliferative disorders.

Baxter EJ, Kulkarni S, Vizmanos JL, Jaju R, Martinelli G, Testoni N, Hughes G, Salamanchuk Z, Calasanz MJ, Lahortiga I, Pocock CF, Dang R, Fidler C, Wainscoat JS, Boultwood J, Cross NC

British journal of haematology. 2003 ; 120 (2) : 251-256.

PMID 12542482

PDGFRA activating mutations in gastrointestinal stromal tumors.

Heinrich MC, Corless CL, Duensing A, McGreevey L, Chen CJ, Joseph N, Singer S, Griffith DJ, Haley A, Town A, Demetri GD, Fletcher CD, Fletcher JA

Science (New York, N.Y.). 2003 ; 299 (5607) : 708-710.

PMID 12522257

Chronic myeloproliferative disorders with rearrangement of the platelet-derived growth factor alpha receptor: a new clinical target for STI571/Glivec.

Trempat P, Villalva C, Laurent G, Armstrong F, Delsol G, Dastugue N, Brousset P

Oncogene. 2003 ; 22 (36) : 5702-5706.

PMID 12944919

Molecular and cytogenetic characterization of a novel translocation t(4;22) involving the breakpoint cluster region and platelet-derived growth factor receptor-alpha genes in a patient with atypical chronic myeloid leukemia.

Safley AM, Sebastian S, Collins TS, Tirado CA, Stenzel TT, Gong JZ, Goodman BK

Genes, chromosomes & cancer. 2004 ; 40 (1) : 44-50.

PMID 15034867

Contributor(s)

Written 09-2004 Barbara K Goodman, Anne Michele Safely

Clinical Cytogenetics, Molecular Diagnostics Laboratories, Duke University Health System, Box 3631, Durham, NC 27710, UK

Citation

This paper should be referenced as such :
Goodman BK, Safely AM . t(4;22)(q12;q11.2). Atlas Genet Cytogenet Oncol Haematol. Septem ber 2004 .
URL : http://AtlasGeneticsOncology.org/Genes/t0422q12q11ID1153.html

© Atlas of Genetics and Cytogenetics in Oncology and Haematology
indexed on : Sat Dec 6 18:02:37 2008

Home Genes Leukemias Solid Tumours Cancer-Prone Deep Insight Case Reports Journals Portal Teaching

For comments and suggestions or contributions, please contact us

jlhuret@AtlasGeneticsOncology.org.

Disease	Reported in 3 cases; myeloproliferative disorder : atypical chronic myeloid leukemia (aCML) (Philadelphia chromosome-negative) .
Etiology	One case was post-treatment for lymphoma, thus suspected to be a secondary MPD.
Clinics	3 cases shared characteristics of splenic enlargement, eosinophilia and male predominance.


	Peripheral blood smear showing anemia, leukocytosis with increased granulocytes and precursors, and eosinophilia. Bone marrow showing hypercellularity with marked myeloid hyperplasia, mild eosinophilia, no increase in blasts.

Prognosis	One patient on treatment with good response to imatinib mesylate.

Note	t(4;22)(q12;q11.2), easily distinguished cytogenetically.
Cytogenetics Molecular	FISH for BCR- ABL1 is negative for fusion but will show extra signal for BCR when using the dual fusion probe set. BCR-ABL1 PCR is negative.


	Interphase FISH showing 3 signals for BCR (green), suggesting rearrangement. Two normal signals for ABL1 (red).

Probes	BCR-ABL dual fusion probe set.
Additional anomalies	The t(4;22) was observed as the sole anomaly in the few reported cases to date.

Gene Name	PDGFRA
Location	4q12
Note	Member of the protein-tyrosine kinase receptor family subclass III that includes the colony stimulating factor-1, c-KIT, FLT1, and FLT3/FLK2. Suggested role for normal PDGFRA receptor expression during periods of glial cell development and connective tissue growth.
Dna / Rna	23 exons; includes 2 intracellular tyrosine kinase domains, TK1 and TK2 (exons 13-15 and 17-21), 5 extracellular Ig-like domains (exons 3-10), and a hydrophobic transmembrane domain (exon 10). The cytoplasmic region also encodes an ATP binding site.
Protein	170-kD transmembrane glycoprotein that normally binds all PDGF isoforms, AA, AB, and BB at its extracellular Ig domain.

Gene Name	BCR
Location	22q11.2
Dna / Rna	23 exons; alternate splicing.
Protein	160-kDa protein; contains a unique serine/threonine kinase activity and at least two SH2 binding sites encoded in its first exon and a C-terminal domain that functions as a GTPase activating protein for p21(rac).

Note	5'BCR-3'PDGFRA fusion
Description	Fusion of BCR exon 7, 12 or 17 (in 3 cases described) with PDGFRA exon 12, in frame, containing intronic sequence from BCR in two cases.

Description	169 kDa protein in one case, somewhat smaller in two others.
Expression Localisation	Predicted to be localized intracellularly
Oncogenesis	Alteration of tyrosine kinase activity secondary to loss of regulatory and PDGF binding domains; also, BCR domains may significantly affect BCR-PDGFRA downstream signaling pathways as seen with BCR-ABL fusion.

Written	09-2004	Barbara K Goodman, Anne Michele Safely
		Clinical Cytogenetics, Molecular Diagnostics Laboratories, Duke University Health System, Box 3631, Durham, NC 27710, UK