Chorionic villi sample (CVS) chromosome analysis is performed to detect numerical and structural abnormalities such as:
- Larger interstitial or terminal deletions and duplications
Reasons to perform CVS chromosome analysis include:
- Mother’s age 35 years or older at time of expected delivery
- Prior pregnancy or child with a chromosomal abnormality
- Abnormal ultrasound findings
- Multiple miscarriages
- Family history of a chromosomal abnormality
- Mother of any age requesting prenatal testing
- Abnormal non-invasive prenatal screen
A minimum of 20 metaphases are examined and 3 karyotypes are prepared from cultured preparations.
Trisomy Screen by FISH for common aneuploidies is performed in conjunction with the CVS chromosome analysis.
- Submit 20-30 mg chorionic villi in sterile, plastic screw-top tubes filled with transport media
- Label specimen tube with patient’s name and a second identifier (ex: DOB, hospital ID)
- Maintain specimen at room temperature and transport to the Colorado Genetics Laboratory immediately
Samples must be accompanied by a completed a Test Request Form, including pertinent clinical and family history, and gestational age at the time of specimen collection.
Turn Around Time
Generally 7-12 days, depending upon the viability and number of cells in the CVS sample.
Trisomy Screen by FISH for Trisomy 21, 18 and 13, and sex chromosome aneuploidies is performed within 24-48 hours for quick analysis of the most common prenatal genetic conditions.