Aneuploidy by FISH X/Y/18, 13/21

Alphabetical Test listing

Aneuploidy by FISH X/Y/18, 13/21-4280F (blood), 4280A (Amniotic fluid), 4280B (Chorionic villi), 4280C (Products of Conception)

Test name:

Test number:

4280F (blood), 4280A (Amniotic fluid), 4280B (Chorionic villi), 4280C (Products of Conception)

Excellian order number:

LAB4280F - CYTOGENETIC CONGENITAL BLOOD STUDIES
4280A - CYTOGENETIC AMNIOTIC FLUID STUDIES
4280B- CYTOGENETIC CHORIONIC VILLI STUDIES
4280C – CYTOGENETIC PRODUCTS OF CONCEPTION STUDIES

Alternate names:

FISH
Fluorescence in situ hybridization
Perinatal FISH
Trisomy 13, 18 or 21
Sex chromosome aneusomy
Down Syndrome
Edwards Syndrome
Patau Syndrome
Turner Syndrome
Klinefelter Syndrome

Patient preparation information:

For prenatal specimens, patient should receive genetic counseling prior to ordering.

Specimen type:

Sodium heparin (Na hep) whole blood

Collection container:

Dk green Sodium heparin (Na hep), no gel

Volume:

4.0 mL

Minimum volume:

2.0 mL

Collection instructions:

Immediately following collection, mix sample by inverting 8 - 10 times to prevent clotting.

Processing instructions:

This interphase FISH test MUST be ordered with a chromosome study or chromosomal microarray (CMA) analysis.

Transport container:

Alternate specimen type:

Amniotic fluid
Chorionic villi

Alternate collection container:

Amniotic fluid: discard the first 2 mL collected.

Alternate specimen volume:

Amniotic fluid: 20 mL
Chorionic villi: 30 mg (minimum 10 mg)

Alternate transport container:

Amniotic Fluid:

Falcon vial/tube - 15mL

Chorionic villi:

Sterile container filled with CVS Collection Media, sterile Hanks Balance Salt Solution or Sterile Saline

Transport and stability:

Ambient

Reason for rejection:

Improper label (unlabeled or mislabeled)
Wrong container (anticoagulant or solution)
Improper blood/anticoagulant ratio
Delay in transport
Improper storage
Leaking container

Performing lab:

AHL - Cytogenetics: X

Days set up:

2 - 3 times per week

TAT:

1 - 3 days for STAT analysis

Method:

Fluorescence in situ Hybridization (FISH)

Reference ranges:

Normal or abnormal with interpretation.

Note: The Cytogenetics lab does not report mosaic FISH results.

CPT codes:

88271 x 5
88274 x 2

Subject to medical necessity (Y/N):

Yes

LCD/NCD:

Medical necessity

Date created:

02/16/2011

Revised date:

02/24/2026

Review date:

02/23/2026