For Patients

How can PGD/PGS help me?

Preimplantation Genetic Diagnosis (PGD)/Preimplantation Genetic Screening (PGS) is performed in conjunction with an In Vitro Fertilization (IVF) cycle and can significantly reduce the chances of having a baby with a specific genetic condition or chromosomal abnormality. We are able to test for many different diseases, including chromosomal aneuploidy or rearrangements (such as translocations) and single gene disorders.

PGS for aneuploidy (Chromosome Abnormalities)

The purpose of PGS for aneuploidy is to reduce the risk for miscarriage and failed implantation, and to increase a couple's chances for having a successful pregnancy following an In Vitro Fertilization (IVF) cycle. Most individuals have 46 chromosomes (pairs 1-22, X and Y).

Misdivision of egg or sperm cells can result in an embryo with too many or too few chromosomes. This incorrect number of chromosomes is called "aneuploidy." Down Down syndrome, Edwards syndrome, and Turner syndrome are examples of common aneuploidies. These disorders do not typically run in families, but occur spontaneously and are very common in developing eggs and embryos. Up to 60% of early miscarriages are due to aneuploidy, and the risk for aneuploidy increases with a woman's age.

RGI offers testing for all 24 chromosome types, using aCGH or Next-Generation Sequencing, state-of-the-art technologies with the capacity to test all the chromosomes of an embryo, as well as smaller panels that test for only the most common chromosome abnormalities.

PGD for single gene disorders

Some couples request PGD for a specific genetic condition that may run in their family, such as Tay-Sachs disease, cystic fibrosis, muscular dystrophy, sickle-cell disease, or Huntington's disease. Our scientists have over 25 years of experience in testing for single gene disorders, including rare genetic syndromes. PGD can be performed for nearly all single gene disorders, as long as the specific genetic mutation is known. Single gene testing can be combined with PGS (aneuploidy screening), to maximize the chances of having a healthy baby.

PGD for single gene disorders can also be performed in conjunction with HLA matching if needed, in order to recommend embryos that are both HLA-matched to an affected sibling and free of the inherited condition. This is often requested by couples interested in having a child who is HLA compatible with a child who is in need of a bone marrow or cord blood transplant. HLA testing has been performed for families with conditions such as β-thalassemia, sickle-cell disease, Fanconi anemia, hyper IgM, and aplastic anemia.

PGD for chromosomal rearrangements (e.g. translocations)

PGD can be used to test embryos for a previously identified translocation, inversion, or other chromosomal rearrangement. This greatly decreases the risk for miscarriage and/or the birth of a child with multiple congenital anomalies, resulting from an unbalanced chromosome translocation. This increases the chance of a healthy and successful pregnancy.

Does PGD/PGS replace prenatal testing?

No, PGD/PGS does not replace prenatal testing, such as chorionic villus sampling (CVS) or amniocentesis, which are the standard of care during a pregnancy. PGD/PGS greatly reduces the risk of a pregnancy being affected with a genetic disease or chromosome problem, but there is still a 2-5% risk of a misdiagnosis. Prenatal testing is still recommended when a pregnancy is conceived through IVF/PGD/PGS. Our genetic counselors are available to discuss prenatal testing options with you.