| The Fertility Institute of
New Jersey and New York is one of the few centers in the country offering
IVF for couples who do not suffer from infertility but require preimplantation
genetic testing on their embryos. This technique is called PGD, preimplantation
genetic diagnosis, and is used for couples who are at risk for having
children with severe genetic abnormalities. Couples in this situation
undergo IVF, and we test their embryos to see whether each is affected
by the abnormality. We can also use PGD for couples with previous
unsuccessful IVF cycles or with recurrent miscarriages, where embryo
testing can improve the chances of a healthy pregnancy.
The first baby born from PGD was born in 1992 to parents who were
both carriers for cystic fibrosis, a severe genetic disease which
can be avoided through PGD. Since then, we have developed the ability
to test for a wide variety of genetic diseases such as Tay-Sachs,
Fragile X, Fanconi anemia, and many others. To date, there have
been more than 200 births worldwide from PGD offered at select centers.
The ability to diagnose and exclude embryos with genetic abnormalities
prior to the initiation of a pregnancy offers an attractive means
to prevent inheritable genetic diseases. The benefits of PGD include
eliminating the clinical risks associated with genetic testing during
pregnancy through chorionic villus sampling (CVS) or amniocentesis,
as well as avoiding the need to face the horrific decision of terminating
an established pregnancy that is found to be affected with a serious
genetic abnormality.
PGD is a sophisticated procedure, requiring ultramodern laboratory
equipment and skilled microsurgical technique. Here at the Fertility
Institute, our skilled embryology team can remove from each embryo
a single cell containing microscopic bits of DNA, and this DNA can
then be tested for a particular abnormality. At the stage that this
microsurgery is performed, the early embryo consists of eight cells,
each of which is totipotential, itself capable of forming an entire
human being. Therefore, the loss of a single cell at this stage
for testing purposes does not harm the embryo.
Once the cell is removed, its DNA is tested, using either fluorescent
in situ hybridization (FISH) to detect a chromosomal abnormality,
or the polymerase chain reaction (PCR) in which the DNA is amplified
to test for a single gene abnormality. Only embryos that are unaffected
by the genetic problem are replaced into our patient’s uterus.
In the case of sex-linked genetic disorders, such as hemophilia
or Duchenne muscular dystrophy, which generally affect only male
children, PGD can be used to for gender selection to choose only
female embryos which will not be affected by the disorder.
Here at the Fertility Institute, PGD is a powerful tool that helps
us help our patients build healthy families.
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