20q-, deletion 20q12
Acute myeloid leukemia (AML), myelodysplastic syndrome (MDS), myeloproliferative disorder (MPD)
Fluorescence in situ Hybridization (FISH)
5mL peripheral blood in sodium heparin
3mL bone marrow in sodium heparin
Fixed cytogenetically prepared cells in sterile centrifuge tube with pellet visible in 3:1, Methanol:Acetic Acid
4°C to 25°C during transit, but specimens may be transported on refrigerated gel packs. Do not allow the gel pack to come in contact with the specimen. Do not freeze. Extreme temperatures should be avoided.
Clotted specimen; Specimen exposed to extreme temperature; Anticoagulant toxic to cells; Insufficient number of cells
In a normal cell, the expected pattern is the two orange signal pattern. In an abnormal cell containing the deletion, the one orange signal pattern is observed.
Deletions of the long arm of chromosome 20 represent a common chromosomal abnormality associated with myeloid disorders, in particular with myeloproliferative disorders (MPD), myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML). The deletion is rarely seen in lymphoid malignancies. Other chromosome changes commonly occurring with deletion 20q are monosomy 5/5q-, monosomy 7/7q-, and trisomy 8. FISH can detect this abnormality in either interphase or metaphase cells.