PCR – is a technique to detect a mutation in a single gene such as cystic fibrosis.
Is PGD for me?
The test has limited usefulness because of the high-cost of the procedure, technical difficulties in performing the procedure and diagnostic limitations. PGD is indicated in patients with abnormal chromosomes or genetic abnormalities, such as (cystic fibrosis), as a way to prevent transmitting the abnormal gene to their children.
What is PGS?
Routine genetic screening of all embryos to select only the normal ones during IVF is called Preimplantation Genetic Screening (PGS).
Why not routinely screen all embryos for genetic abnormalities?
To date, PGS has not been shown to be helpful for patients with repeated IVF failures,
older patients or patients with
recurrent miscarriages. In fact, some marginal embryos may survive implantation into the uterus but may be vulnerable to damage from embryo biopsy. This means that women with poor quality embryos have a significantly lower probability of pregnancy if their embryos are biopsied.
PGS is associated with 15-20% false positive results. This means that 15-20% of normal embryos may be misread as abnormal, making them unsuitable for transfer into the woman’s uterus. Another problem with PGS is that there is a 5% false-negative results (undetected abnormal embryos), necessitating amniocentesis later in pregnancy to make sure that the embryo is completely normal.
The Practice Committees of SART and ASRM published an assessment of PGD/PGS. It concluded that available evidence does not support the use of PGS, as currently performed, to improve live-birth rates in patients with
advanced maternal age, with previous implantation failure and patients with
recurrent pregnancy loss. BocaFertility’s policy is to offer PGD to those patients at risk of transmitting a chromosomal abnormality or single gene defect such as cystic fibrosis and for couples seeking non medical gender (sex) selection since the PGD results also include information on the gender of the embryos.
Genetic Counseling and Testing
BocaFertility now offers all patients pre-screening with the Counsyl Universal Carrier Screening test,
a non-invasive test that uses a saliva sample to determine whether individuals carry certain mutations for over
100 different genetic conditions. This represents a major advance in genetic carrier screening, as it is more comprehensive
than the standardly-used carrier screening panels for cystic fibrosis, sickle cell disease, and Ashkenazi Jewish diseases.
At the same time, it is considerably less expensive than running all these tests individually. Furthermore, the Counsyl screening
test includes many additional conditions not previously screened for, and is universally applicable to both genders and all ethnic groups.
In most cases, if an individual is found to be a carrier of a certain condition, there are no adverse effects on his/her personal
health. However, if both parents are carriers of the same condition, their children will have a significant risk of being affected
with the specific genetic disease. In the event that carrier testing reveals both parents to be carriers, BocaFertility offers PGD
as an option to minimize the likelihood of having a child with the genetic condition. It is important to note a negative carrier
screening test reduces, but does not completely eliminate, the possibility that an individual is a carrier of a genetic disease.
A board certified genetic counselor is available to review the results of this carrier screening phone or email with individual patients.
Some common conditions included in the Universal Screening test include, but are not limited to: Cystic Fibrosis, Sickle Cell
Disease, Beta Thalassemia, Tay-Sachs Disease, Galactosemia, Gaucher Disease, Spinal Muscular Atrophy (SMA), Polycystic Kidney
Disease, and Phenylketonuria (PKU).
For more information about the Counsyl Universal Carrier Screening go to:
www.counsyl.com
To learn more about PGD at BocaFertility give us a call at 888.368.1211. |