Test Name
Trisomy 21*
Test Code
F T21
Synonyms
+21, CEP 21
Associations
Down syndrome
CPT Codes
88275, 88271, 88291, 88273
Turnaround Time
9
Specimen Requirements
5mL peripheral blood in sodium heparin Fixed cytogenetically prepared cells in sterile centrifuge tube with pellet visible in 3:1, Methanol:Acetic Acid
Specimen Stability
Blood = 4°C to 25°C, specimens are stable up to 72 hours Fixed cell pellets are stable for years when stored at -28°C to -15°C
Storage & Handling
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.
Causes for Rejections
Clotted specimen; Specimen exposed to extreme temperature; Anticoagulant toxic to cells; Insufficient number of cells
Description
An extra copy of chromosome 21 is the cause of Down syndrome. An increase risk is seen with the increase in maternal age.
