Genetic Testing And Diagnosis
Genetic Testing & Diagnosis
Current advances in genetic science have made it possible for scientists to help patients who are undergoing fertility treatments identify many of the genes responsible for physical traits, including inherited diseases and gender. First, a simple saliva test offered to all our fertility patients helps to identify some genetic disease risk before they begin their conception protocols. Then, for some doing IVF, advanced genetic testing, such as Preimplantation Genetic Testing, makes it possible to screen for genetic diseases that run in their family. It is also extremely helpful for those with recurring pregnancy loss by identifying those embryos that may be optimal for implantation.
All our fertility patients are offered this very simple, painless pre-conception genetic test. Monterey Bay IVF was one of the first centers on the West Coast to partner with Counsyl for their revolutionary “saliva” genetic test. It is recommended for both men and women of reproductive age that are planning to conceive. The patient is provided with a kit and in minutes the test is done, mailed and results available online within two or three weeks.
This is an invaluable test of cystic fibrosis and spinal muscular atrophy, two of the many conditions on the “Universal Genetic Test”. Each person has two copies of every gene—one inherited from their mother, the other from their father. The majority of gene pairs in the body are considered normal. However, some genes malfunction due to a change in the DNA, or what’s known as a genetic mutation. Counsyl’s “Universal Genetic Test” checks for mutations that cause so-called single gene or “Mendelian” disorders.
According to Counsyl, “Carrier testing is a way to see whether we “carry” certain mutations in our DNA that may not affect us, but can cause our children to inherit a disease. If both parents are “carriers” of the same mutation, their child has a significant chance of suffering from a serious genetic disease, like cystic fibrosis, spinal muscular atrophy (SMA), fragile X, sickle cell disease, or Tay-Sachs disease.”
This test is covered by most insurance carriers and if not covered, is offered by Counsyl to the patient at an extremely reduced price. Counsyl’s goal is to eradicate some of these devastating hereditary disorders by having everyone tested! “We passionately believe that genetic testing is a human right, not a luxury. And now that we have the Universal Genetic Test, there is no reason for one more baby to die from a preventable genetic disease.”
Pre-Implantation Genetic Diagnosis (PGD)
For those choosing to do in vitro fertilization (IVF) and may be carriers for a genetic disease, preimplantation genetic diagnosis (PGD) is an invaluable technology. It can radically increase the chance of healthy offspring in those patients.
The couple going through IVF will need to produce at least one embryo, although multiple embryos are ideal in order to produce better test results. PGD is a specialized genetic test used during in vitro fertilization (IVF) to evaluate one cell, or cells, from an embryo for chromosome abnormalities and/or diseases due to a single gene mutation. On Day 3 or Day 5, a small cellular sample is removed (biopsied) by our embryologist from each embryo and sent to a highly specialized pre-implantation laboratory. PGD performed on Day 3 after fertilization, has one cell, called a blastomere biopsied (removed) from each embryo and on Day 5 after fertilization a few cells from the trophectoderm are biopsied from each embryo.
The biopsied cells are sent to the testing laboratory for analysis and the embryos themselves remain at the IVF center to await the testing results. For Day 3 testing results are delivered on the morning of Day 5 before it is time for embryo transfer. Day 5 testing usually requires that the embryos be frozen until test results are returned, after which the embryos are thawed and transferred in a future IVF cycle. The accuracy of PGD is generally between 95% and 99%. Embryos with normal test results can be selected for transfer to the mother’s uterus.
Pre-Implantation Genetic Screening (PGS)
Pre-implantation genetic screening is recommended for women who have experienced multiple miscarriages or repeated failure in IVF embryo implantation. This type of screening is available to those who produce six or more embryos through IVF. The embryos are tested for chromosomal numbers.
PGS can also enable parents to identify the sex of the embryos for gender selection. Please read more about “Family Balancing” and why it might be an option for some couples. Those who opt for PGS for gender selection are made aware that undergoing this procedure may diminish the number of embryos available to transfer.
Benefits of Genetic Testing of Embryos
- Only healthy embryos are implanted.
- Can screen for a specific genetic defect a child might inherit from its parents.
- A range of chromosomal abnormalities can be screened for.
- Since genetic defects in embryos are a primary cause for implantation failure and miscarriage, screening can improve chances of a viable pregnancy.
- Encourages single embryo transfer by selecting that embryo deemed the “healthiest”.
- The patient can select the gender of the embryo to implant.