Constitutional FISH AneuVysion FISH

AneuVysion, an FDA-approved fluorescent in situ hybridization (FISH) technology, is a set of probes used on uncultured amniocytes or chorionic villi to rapidly detect trisomies 13, 18, and 21  and sex chromosome aneuploidy.  Together these conditions account for a significant proportion of all chromosome abnormalities identified at the time of amniocentesis and the majority of clinically significant chromosomal abnormalities detected in live-born infants. 

The AneuVysion FISH screen is particularly useful when there is high suspicion for chromosome aneuploidy involving the targeted chromosomes based on fetal anomalies detected by ultrasonography.   Results are rapidly available, within 24-72 hours after the amniotic fluid is received in the laboratory.  This FISH test is considered preliminary and should be confirmed on chromosome analysis or chromosomal microarray.

Slides are prepared per standard protocols and 100 interphase cells are scored for each probe under fluorescence microscopy.

Amniotic Fluid:  18-24 mL.
Discard or separately collect first one or two mL fluid (can be used for AFP). If fluid is bloody, add 0.5 mL sodium heparin (1000 units/mL) to each 10 mL of fluid and mix well.

CVS:  Collection of Samples:
All specimens should be handled as aseptically as possible and immediately transported to the laboratory.  Transport medium is available from our laboratory upon request.  [Transport medium: 500 ml Ham F-10 (Gibco), 0.5 ml gentamycin, 5 ml sodium heparin (1,000 USP units/ml).  Aliquot 10 ml of transport medium into sterile, screw-cap plastic test tubes.  The shelf life of the transport media is 3 months at 4°C or 1 year frozen. 

Procedure:

1. Use approximately half of medium (5ml) in vial for syringe receiving villi.
2. Pour remaining half of medium from vial into sterile Petri dish.
3. Villi are transferred from syringe to Petri dish for evaluation.  If sample contains a number of red blood cells, more medium may be added to dilute for better visualization.  It may also be necessary to rinse syringe with fresh medium.
4. If an adequate sample is obtained (an adequate amount of villi is 20-25 mg), use forceps and sterile technique to transfer villi to one of the vials that still contain medium.  Samples 5-10 mg will be accepted with disclaimer due to small sample size.
5. Label vial with patient name, date of birth, and gestational age.

Products of Conception Tissue choices:
If no identifiable fetus is present (e.g. missed abortion):
   1. Entire specimen
   2. Biopsy of fetal side of placenta (e.g. villi)
   3. Fetal membranes

If fetal demise, stillbirth, or neonatal demise:
   1. Amniotic fluid may be collected prior to elective termination.(See information for Chromosomal Microarray-Prenatal Diagnosis for instructions.)
   2. Biopsy of fetal side of placenta (e.g. villi) - preferred
   3. Skin:  deep tissue sample, at least 3 cubic mm – preferred
   4. In addition to the above, other tissues may be acceptable.  Please contact our lab to discuss your options.  Ask to speak with a Microarray Technologist.

DO NOT PLACE IN FORMALIN.  Tissue must be suspended in sterile culture media (e.g. RPMI, α-MEM, Ham’s F-10) or tissue transport media supplied by our lab.  If none of these are available you may use the following:  sterile Ringer’s solution, sterile normal saline.

A REQUISITION FORM MUST ACCOMPANY ALL SAMPLES.  Please include detailed clinical information, including ethnicity, clinical history, and family history.

Mon - Sat

≤3 days: Contact Lab at 855-KDL-1LAB (535-1522) - Time varies depending on number and type of tests performed.

• Keep the specimen at room temperature during transit.
• Do not use the cold pack provided in the KDL shipping kit.
• Ship the specimen overnight express, using the FedEx priority overnight label provided. 
• The specimen must arrive at the lab no more than 24 hours after collection.
• Contact Client Services at (855) 535-1522 for shipping kits and instructions.