Trisomy FISH Screen (13,18,21,X,Y) (Chorionic Villus Sampling (CVS))

Turnaround Time

4 days

CPT Code(s)

88235, 88275 x2, 88271 x4, 88291

Cost

$1372

• Trisomy 13
• Trisomy 18
• Trisomy 21 also Down syndrome

The trisomy screen can be used as a rapid initial screen for some of the more common aneuploidies. FISH should be used in conjunction with G-banded chromosome analysis.

FISH: Fluorescence in situ hybridization is a molecular cytogenetic technique in which fluorescently labeled DNA probes are hybridized to metaphase spreads or interphase nuclei.

Chorionic Villus Sample (CVS) is the specimen type for this test. 20-30 mg of a chorionic villus specimen (CVS) by either the transabdominal or transcervical method is required. If sending cultured flasks, 2x T25 confluent flasks are required. Maternal samples are required to accompany CVS. 4-5 ml of peripheral blood should be collected in an EDTA (lavender top) tube. Additional specimen types for parental samples include saliva and extracted DNA.

CVS: Specimen should be kept at room temperature; do not freeze or refrigerate. Specimen should be sent by courier or overnight mail to arrive at the laboratory the next day.