Parental Support is a new technology for Preimplantation Genetic Screening (PGS) to test all 24 chromosomes in a single cell from an embryo (called a blastomere) for a variety of genetic abnormalities within 24 hours. Test reliability typically exceeds 99% and results are returned in time for Day 5 embryo transfer. Parental Support is a proprietary technology developed by Gene Security Network.

Aneuploidy can affect any chromosome.  When only a portion of the chromosomes are evaluated, as with FISH, there is still a chance for aneuploidy of one or more of the untested chromosomes.  Studies comparing analysis of nine chromosomes to 24 chromosomes have found that up to 25% of aneuploid embryos would test normal with FISH simply because the other chromosomes were not tested. This means that 1 in 4 blastomeres with a problem would not be detected using FISH.

Accurate screening of each embryo across all 24 chromosomes greatly decreases the chance that an aneuploid embryo will be transferred to the mother. As embryos with aneuploidy are prone to miscarriage or often fail to implant at all, this should in theory improve the chance of a successful IVF cycle and pregnancy.

While there are some technologies, such as CGH, that can screen all 24 chromosomes, delivering results can take up to several weeks. This means that the embryos must be frozen until the testing is completed. Embryo freezing may be associated with a reduction in embryo survival. For couples who may only have one or two viable embryos, this may be a significant problem.

With Parental Support, results on all 24 chromosomes are returned early on the morning of Day 5. This means that the embryos do not need to be frozen and can be transferred during the same IVF cycle.

Parental Support overcomes many of the limitations typically associated with the testing of just a single cell.  Because so little genetic material is available from a single cell, results on one blastomere from an embryo are inherently error-prone, even with the best testing and laboratory methods.  Although new microarray testing technologies can analyze DNA from all 24 chromosomes using thousands of probes, these technologies require a greater volume of  DNA than the amount retrieved from a single cell.  DNA from a blastomere can be amplified (copied) to create a greater volume for testing; however, the quality of the amplified sample is poor, which increases the chance for testing errors. 

Parental Support compensates for the limitations of single cell amplification and testing by using DNA from both parents to enhance the results on each embryo. Many cells can be easily collected from the parents through a painless cheek swab, providing ample DNA for a full, accurate analysis on both parents. Since the DNA in the embryo is derived from the mother and father, Parental Support leverages the availability of parent samples to create a much more effective test on single blastomeres.

Parental Support works in the following way:

1. First, Parental Support uses a state-of-the-art Illumina microarray testing platform to screen all 24 chromosomes. The DNA from the single blastomere is amplified and added to an array that contains hundreds of thousands of tiny DNA probes. Each DNA probe binds to a specific area of a specific chromosome. These probes are much smaller than FISH probes, so small that they cannot be seen under a microscope and are instead read by a machine called a scanner.
2. The microarray scanner results cover all 24 chromosomes but are ‘noisy’, or difficult to interpret, due to the poor quality of the DNA sample produced through amplification of just one cell. However, genetic data produced through microarray analysis of thousands of cells from the cheek swab samples of the biological parents can be used to clarify the blastomere results. Parental Support uses a sophisticated bioinformatic algorithm that incorporates genetic data from both parents to clean and correct errors produced during the laboratory analysis. The final results are a highly accurate representation of the genetic composition of the blastomere.

This two step testing process significantly increases PGS test accuracy and is vastly superior to previous methods.

PGS for aneuploidy may be recommended by your doctor if you are at increased risk for aneuploidy in your pregnancies. Couples with one or more of the following have a higher chance for aneuploidy in future pregnancies:

• Women aged 35 and older


• Recurrent miscarriages of unknown cause


• A previous child or pregnancy with a chromosomal abnormality


• Previous unsuccessful IVF cycles

No. There are many different factors affecting the chance of IVF success and no test can guarantee the birth of a healthy baby. Although Parental Support offers the most advanced PGS technology available, there are limitations to all PGS tests in part because the single cell analyzed from the embryo may differ genetically from the other cells in the embryo, a condition called mosaicism.

With any pregnancy, there is a 3-5% risk for birth defects or genetic conditions and many of these are not detectable prior to implantation or even during pregnancy. Parental Support detects the portion of birth defects caused by aneuploidy (extra or missing chromosomes) but does not identify other structural chromosome abnormalities such as balanced translocations or small rearrangements of chromosome material. Also, as with all types of PGS, Parental Support does not analyze specific genes unless specifically requested, so it will not routinely identify single gene disorders like cystic fibrosis, muscular dystrophy, or Tay-Sachs disease.

In addition to analysis of all 24 chromosomes, Parental Support offers several unique advantages:

• Detection of haploidy and polyploidy:
  Haploidy and Polyploidy occur when a whole set of chromosomes is missing or extra in the cells of an embryo. With haploidy the cell has only one copy of each chromosome for a total of 23, and with polyploidy the cell has three or more copies of each chromosome for a total of 69 (triploidy) or 92 (tetraploidy), instead of the normal 46. Data suggests that these types of abnormalities are found in up to 10% of embryos created during IVF. Embryos with haploidy and polyploidy almost never implant to create a pregnancy, and those that do almost always result in miscarriage. In rare cases a baby may be born with triploidy, but the condition is always fatal soon after birth.


• Individually calculated test error rates:
  Parental Support calculates a test reliability specific to each individual blastomere and chromosome analyzed. This means that if the results on a given blastomere cannot be reported with confidence, the doctor will know which chromosome is responsible, along with the degree of risk, and can use this information to make the best clinical decisions.


• Detection of Uniparental Disomy:
  Uniparental Disomy (UPD) is a rare condition in which both chromosomes of a particular chromosome pair come from the same parent, instead of one from each parent. UPD can be associated with specific genetic disorders depending on the particular chromosome involved and the parent of origin of the two copies. The most common genetic disorder associated with UPD is Prader-Willi syndrome which occurs in about 1 of every 10,000 children and is characterized by mental retardation, childhood obesity and severe behavioral and emotional problems. Thirty percent of children with Prader-Willi have maternal UPD for chromosome 15, having received two copies of chromosome 15 from their mother and none from their father.
  
  Parental Support is able to detect the presence of uniparental disomy and will report this finding for those chromosomes in which UPD is known to result in a serious genetic condition.


• Detection of DNA contamination:
  Any time the DNA of a single cell such as a blastomere is amplified for testing, there is a risk of also amplifying foreign DNA that was inadvertently present along with the sample cell. Contamination may result when one or more additional sperm are present in the tube with the blastomere, or when foreign DNA from the lab environment gets into the tube with the blastomere DNA. Both of these situations can affect the results.
  
  Parental Support performs a number of unique quality control checks to detect the presence of foreign DNA and assure the highest reliability and accuracy of our results.
  
  Additionally, by referencing the DNA from the blastomere sample with DNA from each parent, DNA from a source other than the blastomere becomes easily identifiable. Other PGS technologies do not perform these measures and cannot rule out contamination in their samples.


• Determination of the parental origin of a trisomy or monosomy
  In some cases if a couple repeatedly has aneuploid embryos, it may be helpful to understand the parental origin for the extra or missing chromosome to determine whether aneuploidy may be occurring for a reason other than chance chromosome non-disjunction. Although not routinely reported in the testing results, information on parental origin is captured as part of the Parental Support process and is available upon request by the IVF doctor.


• Fast turnaround time:
  Results are available in time for embryo transfer on “Day 5”, so the ‘fresh’ embryo can be transferred. Embryo freezing is not required.

PGS with Parental Support is only available through partner IVF centers. Talk to your physician regarding a referral.