PGT-SR: Preimplantation Genetic Testing for Chromosomal Structural Rearrangements
PGT-SR is a genetic test that can determine whether embryos created through IVF have chromosomes that are arranged abnormally or are not sized correctly. Generally, embryos with such abnormalities do not result in successful pregnancies. If you are at risk, your fertility specialist may recommend IVF with PGT-SR to help you get pregnant faster and with a greater chance of having a healthy baby.
Performed in conjunction with PGT-A, or preimplantation genetic testing for aneuploidy, PGT-SR tests your embryos for specific structural rearrangements for which you and/or your partner are at risk. Such rearrangements can increase the chance of implantation failure, miscarriage or the birth of a baby with a chromosome disorder. Identifying affected embryos allows your fertility specialist to transfer only those that contain the correct amount of chromosome material, increasing your chance of a successful pregnancy.
PGT-SR allows your fertility specialist to confidently transfer only one embryo at a time, and can greatly improve the chance of your IVF cycle being successful. This test may also reduce the risk of fraternal twins, miscarriage and chromosomal disorders in your children, and may help you achieve pregnancy more cost-effectively.
Who benefits from PGT-SR?
PGT-SR is recommended for people who are carriers of a balanced translocation or inversion and wish to conceive a baby.
People who carry a balanced translocation or inversion have the correct amount of genetic information, but some of this information is in a different orientation than expected. Although most carriers of balanced chromosome rearrangements are healthy, they are at higher risk of producing embryos with an abnormal amount of genetic material (known as an unbalanced rearrangement). Adults often discover that they are carriers only when they try to have children and have trouble getting or staying pregnant.
PGT-SR may be recommended if you or your partner is a carrier for a:
- Reciprocal translocation: Pieces of chromosomes have switched places.
- Robertsonian translocation: Chromosomes link together and create an abnormal chromosome count. This can cause conditions including trisomy 13 and uniparental disomy (UPD). This type of rearrangement may also result in translocation Down syndrome.
- Inversion: Part of a chromosome is turned upside down and reinserted back into the chromosome.
How does the Ovation PGT-SR process work?
Ovation Genetics will work closely with your fertility care team and IVF laboratory to personalize your test, secure sample cells for testing, and provide you with a detailed report and access to a genetics counselor to help you understand your results.
- Case review – The Ovation Genetics team reviews the specific rearrangement identified in your family.
- IVF – Your eggs are retrieved and fertilized at your IVF laboratory.
- Biopsy – A skilled embryologist removes four to seven cells at the blastocyst stage of embryo development to be sent to a specialized IVF genetic testing lab for testing. Your embryos stay safely frozen at your fertility center.
- PGT – Expert geneticists perform PGT-SR on the sample cells to detect potentially unbalanced forms of chromosomal rearrangement. At the same time, high-resolution next generation sequencing is used to count the number of chromosomes in each embryo – a test called PGT-A.
- RESULTS – Once testing is complete, a detailed report is sent to your doctor identifying each embryo’s chromosomal analysis, which helps in the selection of an embryo most likely to result in a live birth.
- EMBRYO TRANSFER – Your fertility specialist will transfer the selected embryo to your uterus, increasing the chances that you will have a baby that is neither a carrier of nor affected by the chromosomal structural rearrangement.
- STORAGE – Should you have extra chromosomally normal embryos left over after your cycle, you can choose to keep them cryopreserved and stored for future use, with the confidence that they will provide a high chance of success when you are ready to add to your family.
Ask your fertility specialist about PGT-SR
To learn more about Ovation PGT-SR, or to locate a fertility specialist in your area who offers Ovation genetic testing, please contact us. Our client case specialists will be happy to assist you.