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CEP 7 -7/7q31- by FISH

Test Code


Test Synonyms

-7/7q-, -7/del(7)(q31), deletion 7q31


Acute myelogenous leukemia (AML), Myelodysplastic syndrome (MDS)


Fluorescence in situ Hybridization (FISH)

Turnaround Time

3-5 days

Specimen Requirements

5.0 mL (min. 3.0 mL) peripheral blood in sodium heparin preferred, EDTA accepted
3.0 mL (min 1.0 mL) bone marrow in sodium heparin preferred, EDTA accepted
5 mm^3 fresh tissue or 3.0 mL (min. 2.0 mL) FNA in MPLN RPMI media

Specimen Stability
Peripheral blood and bone marrow stable at 18-25°C for 72 hours
Fresh tissue or FNA at 2-8°C stable for 72 hours
Storage & Handling

Whole blood and bone marrow, ship ambient.
Fresh tissue or FNA, ship in a Styrofoam container with a cool/refrigerated pack. (Do not allow cool pack to directly contact sample)

Causes for Rejection

Clotted specimen; Apecimen exposed to extreme temperature; Anticoagulant toxic to cells; Insufficient number of cells; Improper fixative

Reference Range

In a normal cell, the expected pattern is the two orange, two green signal pattern. In a hybridized abnormal cell containing the deletion, the one orange, two green signal pattern is observed. In an abnormal cell containing a monosomy 7, one orange and one green signal is observed.


Complete or partial loss of chromosome 7, predominantly deletion of 7q, is a recurrent chromosomal aberration found in myeloid disorders such as myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML). Deletion of the long arm of chromosome 7 has been reported in a few cases of chronic lymphoproliferative disorders: splenic marginal zone lymphoma, hairy cell leukemia (HCL) and lymphoplasmacytoid lymphoma (LPL).

Abnormality of chromosome 7 can occur as the sole chromosome change or associated with other cytogenetic defects. Other chromosome changes commonly occurring with 7q- are monosomy 5/5q-, trisomy 8 and 20q-.

FISH can detect this abnormality in either interphase or metaphase cells.

  1. Parker Torrey M et al. (2008). Cancer Genetics and Cytogenetics. 182:122-125.
  2. Rezinova Jana B et al. (2007). Cancer Genetics and Cytogenetics. 173:10-16.
  3. Desangles F. (1999). -7/del(7q) in adults. Atlas Genet Cytogenet Oncol Haematol.
  4. Dohner K et al. (1998). Molecular cytogenetic characterization of critical region in bands 7q35-q36 commonly deleted in malignant myeloid disorders. Blood. 92(11):4031.