The XA X/Y mix of specific probes allows detecting copy number variations for chromosomes X and Y. The probe mix is composed of repetitive sequences which hybridize to the centromeric region of chromosomes X in green and Y in orange.

Probe maps for selected products have been updated. These updates ensure a consistent presentation of all gaps larger than 10 kb including adjustments to markers, genes, and related elements. This update does not affect the device characteristics or product composition. Please refer to the list to find out which products now include updated probe maps.

Probe map details are based on UCSC Genome Browser GRCh37/hg19, with map components not to scale.

Numerical aberrations of autosomes 13, 18, 21, and sex chromosomes X and Y account for 95% of birth defects in newborns. FISH applied to uncultured amniocytes provides a method to identify those aberrations much faster than conventional chromosome analysis. It has become a standard to provide preliminary results for the detection of anomalies in less than 12 hours.

Repetitive sequences around the centromeric regions of chromosomes X and Y can reliably identify Klinefelter syndrome (47,XXY), Triple-X syndrome (47,XXX), Turner syndrome (45,X0), and 47,XYY.

XA X/Y was hybridized to normal uncultured amniocytes from a male fetus.

• Bryndorf et al (1996) Am J Hum Genet 59:918-926
• Tepperberg et al (2001) Prenat Diagn 21:293-301
• Stumm et al (2006) Cytogenet Genome Res 114:296-301