2011: An In-Vitro Odyssey

Modified multiple displacement amplification genetic testing now offered for in-vitro fertilized embryos

(RxWiki News) In-Vitro Fertilization often yields several embryos for a couple to implant within a woman. For couples who may be carriers of a genetic disease, this poses a problem that seems to now be addressed by Johns Hopkins researchers.

A technique called "modified multiple displacement amplification" allows researchers to copy the DNA from embryos formed by in vitro fertilization and perform several rounds of genetic tests on this copied DNA.

"Genetic testing enables couples to see their embryos' future."

Paul Brezina, M.D., M.B.A., a clinical fellow at Johns Hopkins University in obstetrics and gynecology reports that researchers at Johns Hopkins now have the ability to enlarge the genomic DNA of embryos and accurately test a single-gene. Because of the ability to duplicate one cell, researchers can also perform aneuploidy screening.

Before now, this double screening wasn't available. Researchers could only test for one or the other.

Brezina goes on to explain that currently, parents find out about genetic disorders they can pass on to their children by having a child afflected with a genetic disease, such as cystic fibrosis or Tay-Sachs disease.

Now, couples are able to view their future children genetically during preimplantation genetic diagnosis (PGD). Scientists take one cell out of an eight cell embryo, duplicate it numerous times and then perform the now available sophisticated genetic testing.

As great as PGD is, there is an obvious downside. These embryos who've had a cell borrowed early in their conception, are more susceptible to chromosomal disorders. Most notably, they have a greater exposure to Down syndrome.

Patients with genetic predispositions that will possibly pass on to their children are now having splendid results. William G. Kearns, Ph.D., associate professor of obstetrics and gynecology at Johns Hopkins University, also oversees the Shady Grove Center for Preimplantation Genetics in Rockville, MD, where he has offered combined PGD and aneuploidy testing to more couples in 2011.

Five of these couples have achieved a promising pregnancy employing PGD. Kearns shares that one of these lucky couples are carriers of Fragile X syndrome, which is a genetic disease that can cause mental instability. 

This patient had two first trimester miscarriages. Applying the PGD technique to this woman has allowed her to have a successful pregnancy.

Review Date: 
May 24, 2011