Together, trisomies 13, 18, and 21 (Down syndrome) and sex chromosome aneusomies account for nearly two-thirds of all abnormalities identified at the time of amniocentesis, and 85-90% of clinically significant chromosomal abnormalities detected in live-born infants. Review of AneuVysion testing of over 29,000 amniotic fluid samples has found that the test is 99.9% accurate for the detection of trisomies 13, 18, 21, and aneusomies of X and Y.

Aneuvysion Test Benefits

Because the results are rapidly available, within 24 hours after the amniocentesis sample is received in the laboratory (rather than 7-22 days for routine chromosome analysis), patients can benefit psychologically from a shorter time period of uncertainty. An expected AneuVysion result may allow patients a sense of relief in knowing that the majority of chromosome abnormalities for which their fetus was at risk have been ruled out with a very high degree of accuracy. Importantly, in accordance with professional standards, the availability of AneuVysion results along with consistent clinical information (i.e., fetal anomalies detected by ultrasonography) allows for pregnancy management options that otherwise might not be available due to late gestational age. Finally, in the rare case of a culture failure when standard cytogenetic results cannot be obtained, information on chromosome number for the most likely aneusomies is available. 

AneuVysion Kit Contents

Each AneuVysion kit includes:

• Five FISH probes packaged in two probe mixtures 
• Wash reagents
• DAPI counterstain
• Package insert with detailed protocol information

Both Mixture #1 and Mixture #2 are complete with labeled probes and non-labeled blocking DNA in hybridization buffer.

Indications and Limitations of Use

Intended Use

For In Vitro Diagnostic Use

The AneuVysion (Vysis CEP 18, X, Y-alpha satellite, LSI 13 and 21) Multicolor Probe Panel is intended to use CEP 18/X/Y probe to detect alpha satellite sequences in the centromere regions of chromosomes 18, X, and Y, and LSI 13/21 probe to detect the 13q14 region and the 21q22.13 to 21q22.2 region. The AneuVysion kit is indicated for identifying and enumerating chromosomes 13, 18, 21, X, and Y via fluorescence in situ hybridization (FISH) in metaphase cells and interphase nuclei obtained from amniotic fluid in subjects with presumed high risk pregnancies. It is not intended to be used as a stand alone assay for making clinical decisions. FISH results are intended to be used as an aid in the diagnosis of numerical abnormalities of chromosomes 13, 18, 21, X and/or Y in conjunction with other information currently used in prenatal diagnosis, consistent with professional standards of practice [1]. This device is intended for use only with amniocyte cells; it is not intended for and has not been validated for use with other test matrices. This FISH assay will not detect the presence of structural chromosome abnormalities that can also result in birth defects. This FISH assay will be performed in cytogenetics laboratories. 

Limitations

1. The AneuVysion kit has been characterized only for identifying targeted regions of chromosomes X,Y,18,13, and 21 in interphase nuclei from cultured and uncultured amniocyte specimens.
2. The clinical interpretation of any test result(s) should be made in conjunction with other diagnostic laboratory test results and should be evaluated within the context of the patient's medical history and current risk factors. 
3. FISH assay results may not be informative if the specimen quality and/or specimen slide preparation is inadequate.
4. This assay will not detect the presence of structural abnormalities frequently associated with birth defects. The frequency of these occurrences may be population and gestational age dependent.
5. This assay should not be performed on amniocyte specimens with moderate to severe maternal cell contamination. FISH test results on amniocyte specimens with mild maternal cell contaminations should be interpreted with caution.
6. No irreversible therapeutic action should be initiated based on the FISH assay alone. Positive results should be further characterized using traditional chromosome analysis to determine the mutational mechanism accounting for the abnormality detected by FISH. This information may aid in the counseling for the risk that the detected abnormality may occur in future pregnancies [1].
7. Physicians, counselors, and other healthcare providers should understand the risk of abnormalities that the test is not designed to detect. The patient should be informed that there is still a very small risk of low level mosaicsim, cryptic translocations, or other undetectable events that may not be demonstrated by FISH or standard cytogenetic. Additionally, there is a very small risk that some individuals carry a genetic polymorphism that may affect the intensity, presence or absence of the probe signal that may result in a missed diagnosis [17].
8. When the specimen volume is not sufficient to meet the minimum requirements for processing both FISH and standard cytogenetic procedures, the user must carefully weigh the risks and benefits of utilizing any material for FISH. Consultation between the laboratory geneticist and/ or genetic counselor and the patient's physician may aid in clarifying what information is desired, and which testing method should be used [1].
9. Technologists performing the FISH signal enumeration must be capable of visually distinguishing between orange, green and aqua signals.
10. Although the probe for enumerating chromosome 13 spans the Rb1 locus, this probe has not been validated for detecting mutations associated with retinoblastoma. In rare cases, the Rb1 locus may be deleted; this could complicate interpretation of FISH test results. 

CAUTION: United States Federal law restricts this device to sale and distribution to or on the order of a physician or to a clinical laboratory; use is restricted to, by, or on the order of a physician.