5-Chromosome Pre-Implantation Genetic Screening (PGS)
Pre-Implantation Genetic Screening (PGS) allows for the screening of embryos during In Vitro Fertilization (IVF) in order to identify chromosome abnormalities caused by aneuploidy . Viafet's Luminescent™ 5-chromosome FISH analysis screens chromosomes 13, 18 and 21, and the sex chromosomes, X and Y, reducing the chances of transferring an embryo with a chromosomal abnormality caused by aneuploidy and allows for the gender of each embryo to be identified. With over 15 years of experience in Reproductive Genetics, during which over 15,000 samples have been tested, Viafet specializes in PGS.
Please note that FISH is not available in Australia.
- Is Luminescent™ right for me?
- How does Luminescent™ work?
- What is Aneuploidy?
- Where can I get testing?
Is Luminescent™ right for me?
5-chromosome embryo screening by Viafet's Luminescent™ is most often recommended for couples with:
- Concern for, or previous pregnancy with, a Trisomy: In cases of a previous pregnancy involving Down syndrome (Trisomy 21), Edwards syndrome (Trisomy 18) or Patau syndrome (Trisomy 13) or if the couple is concerned about a pregnancy with a Trisomy.
- Interest in Gender Selection or concern for a sex-linked gender illness.
Based on your medical history and personal preference, Viafet advises you to consult with your physician in order to determine if genetic testing such as 5-chromosome Luminescent™ is right for you. For more information about Luminescent™, to discuss any questions related to genetic testing, or to learn where you may complete an IVF cycle with Viafet testing, contact Viafet today.
How does Luminescent™ work?
Completing genetic testing during your IVF cycle provides a wealth of information about each embryo before being transferred back to your uterus. During an IVF cycle, 5-chromosome Luminescent™ can be performed on day 3, 4 or 5 after Egg Retrieval by removing a single cell or cells from the developing embryo. Results are available 12-hours after receiving the samples. Viafet's fast reporting time allows for embryos to be transferred fresh or frozen, depending on your IVF physician's protocol.
Luminescent™ is performed with the use of fluorescent probes that bind to specific chromosomes . Each fluorescent probe is made of a nucleotide sequence specific to either chromosome 13, 18, 21, X or Y. The probes are placed with the embryo sample and hybridise, or find their match. After hybridisation, a microscope that can see fluorescent images is used to count chromosomes 13, 18, 21, X and Y and identify any missing or additional whole chromosomes. Results obtained through Viafet's FISH analysis are >95% accurate.
What is Aneuploidy?
Our bodies are made up of cells containing chromosomes . Each chromosome holds genes that code for the proteins essential for healthy development. In humans, each cell normally has 46 chromosomes. These 46 chromosomes are made of up 22 pairs, one pair from each parent, and the sex chromosomes, X and Y (XX in females and XY in males), making a total of 24 unique chromosomes.
Aneuploidy, what does it mean and how does it happen?
When an individual has more or less than 46 chromosomes, they are said to have a chromosomal abnormality due to aneuploidy , additional or missing chromosomes. Having an extra chromosome, 47 instead of 46, is known as a "trisomy", while having a missing chromosome, 45 instead of 46, is known as a "monosomy".
Aneuploidy can naturally occur either when the egg and sperm cells are being made or as cells multiply and divide during early embryo development and are not necessarily associated with family history. However, the likelihood of aneuploidy occurring in embryos increases with maternal age as ovarian reserve quality diminishes.
Aneuploidy and pregnancy
Most aneuploid embryos either do not implant or result in early pregnancy loss -- over 60% of pregnancy loss or IVF failure can be attributed to aneuploidy. However, some chromosomal abnormalities have a higher occurrence in developing foetuses and can result with a baby being born with an abnormal number of chromosomes. These include:
- Trisomy 21 (Down syndrome)
- Trisomy 18 (Edward syndrome)
- Trisomy 13 (Patau syndrome)
Aneuploidy can also occur in the sex chromosomes, X and Y. These include:
- Klinefelter syndrome (XXY)
- Turner syndrome (X)
- Triple X syndrome (XXX)
- Jacob syndrome (XXY)
Viafet's Luminescent™ 5-chromosome FISH analysis can detect all of the conditions described above. In some instances, there are not entire additional or missing chromosomes but rather small additions or deletions called duplications and deletions - FISH analysis is unable to detect duplications and deletions.
Where can I get testing?
Talk to your IVF physician about 5-Chromosome PGS and if it right for you. If your physician does not yet offer Viafet testing, please suggest that they contact us - testing can get started immediately. If your physician is already offering Viafet testing, all coordination for your case will be completed between your IVF centre and Viafet's team.
With locations in the United Arab Emirates (Dubai and Abu Dhabi), Australia, the Kingdom of Saudi Arabia, Lebanon and more locations coming soon, Viafet's services are available to a wide network of clinicians and patients. If at any time during your journey you have questions or would like to speak with a Genetic Counselor, contact Viafet and we will schedule an appointment immediately.