del(22)(q11.2), deletion 22q11.2
Fluorescence in situ Hybridization (FISH)
*Performed by affiliate laboratory
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
It is recommended that all FISH studies be done in conjunction with routine cytogenetic studies. If the FISH result is normal, a chromosome analysis allows identification of more complex abnormalities.
DiGeorge syndrome is a rare congenital disease caused by a large deletion from chromosome 22, produced by an error in recombination at meiosis. This deletion indicates a loss of several genes from this region with the variation in symptoms relating to the amount of genetic material lost.