Chromosome Analysis
Label Mnemonic: CVS
Epic Lab Code: LAB8265
Downtime Form: A-1a Miscellaneous Request
Commercial Mail-out Laboratory
5231 RCP
356-8593
Specimen(s):
CVS
Specimen Instructions:
Provide a reason for referral with each specimen. The laboratory will not reject testing if this information is not provided, but appropriate testing and interpretation may be compromised or delayed.
Minimum:
20-30 mg from a 15-mL tube containing 15-mL of transport media.
Turn Around Time:
9 days upon receipt at reference laboratory
Reference Range:
An interpretive report will be provided.
Interpretive Data:
Cytogenetic studies on chorionic villus specimen (CVS) are considered more than 99% reliable for the detection of most fetal chromosome abnormalities. However, subtle or cryptic abnormalities involving microdeletions usually can be detected only with the use of targeted FISH testing.

Approximately 3% of CSVs analyzed are found to have chromosome abnormalities. Some of these chromosome abnormalities are balanced and may not be associated with birth defects. A normal karyotype does not rule out the possibility of birth defects, such as those caused by submicroscopic cytogenetic abnormalities, molecular mutations, and environmental factors (ie, teratogen exposure). For these reasons, clinicians should inform their patients of the technical limitations of chromosome analysis before the procedure is performed, so that patients may make an informed decision about pursuing the procedure.
Comments:
Useful For:
Prenatal diagnosis of chromosome abnormalities, including aneuploidy (ie, trisomy or monosomy), structural abnormalities, and balanced rearrangements.

Please print, complete and submit the Informed Consent for Genetic Testing from Mayo Medical Laboratories with the specimen and the A-1a Miscellaneous Request or Epic Req.
Test Limitations:
-False-chromosome mosaicism may occur due to artifact of culture

-True mosaicism may be missed due to statistical sampling error

-Presence of chromosome abnormalities in placental cells that do not
 occur in cells of the fetus (confined placental mosaicism)

-Subtle structural chromosome abnormalities can occasionally be missed
Methodology:
Cell Culture followed by Chromosome Analysis
CPT Code:
88291
88235 (if appropriate)
88267 w/modifier 52 (if appropriate)
88267 (if appropriate)
88267, 88285 (if appropriate)
88280 (if appropriate)
88283 (if appropriate)