New Test For Genetic Diseases

Until recently, amniocentesis was the primary way for expectant parents to learn if their baby might be carrying a genetic disease. The test can be done only after a pregnancy has progressed, sometimes by as much as 24 weeks. If doctors find problems, it often leaves few options and tough choices for parents.

CBS This Morning Health and Medical Correspondent Dr. Emily Senay reports on new genetic testing proceedures available for couples hoping to have healthy babies.

This is good news for people like Doreen and Leonard Fucile. Doreen has an unusual genetic abnormality, which poses a 50-50 risk of being passed-on to an unborn child. If Doreen's baby inherited the problem, it would die within the first few months of pregnancy. Unaware of the problem and determined to have children, the Fuciles suffered seven miscarriages over two years.

What the Fuciles experience may not be necessary. That's because a new test -- known as Pre-implantation Genetic Diagnosis, or PGD -- developed by scientists at New York Hospital/Cornell Medical Center allows doctors to test for diseases before pregnancy even begins.

Here's how the test works: Eggs are taken from the woman and put into a petri dish, where they are artificially inseminated with sperm from the man. Embryos form and begin to grow. When the embryos have eight cells, doctors remove a single cell and test it for genetic diseases. Those embryos which doctors find to be genetically healthy are then implanted into the woman's womb and carried to term.

Dr. Zev Rosenwaks, who helped develop PGD, says the test poses no harm to a developing embryo.

"You can remove a single cell from the three day-old embryo Â… quite safely," Rosenwaks explains. "One can examine that embryo, look for that disease, avoid transferring embryos with that problem, enabling a couple to have children that are normal."

According to Rosenwaks, doctors can specifically test for almost any genetic abnormality, including sickle cell anemia, muscular dystrophy, and cystic fibrosis. But expectant parents wanting to undertake PGD should not have unrealistic expectations. One reason, the cost of the procedure.

During experimental phases, testing was offered at no charge. As of July 1, however, the procedure becomes expensive.

First, there is the cost of invetro fertilization, which can run as much as US$10,000. Additionally, there is a fee for the PGD. New York Hospital plans to charge US$2,000-35,000 depending on the specific genetic diseases for which doctors are searching.

Cost is not the only prohibiting factors for couples seeking PGD. In addition to its high cost, the procedure is not yet widely available. Fewer than ten hospitals around the world offer the testing.

Despite these facts, Doreen and Leonard Fucile are advocates of thprocedure. The Fuciles underwent PGD testing during its experimental phase. They now have a healthy baby girl. For them, Baby Victoria -- healthy in every genetic sense -- is truly a medical miracle.