Prospective Parents and Genetic Testing

In our continuing series, "In Our Genes," CBS News medical correspondent Dr. Jennifer Ashton took a look at genetic abnormalities, which can threaten the lives of babies born with them.

Ashton reported that scientists estimate that one out of every 200 babies born suffers from a single-gene disorder. For parents who have a child with one of these genetic diseases, the experience can be nothing short of devastating.

David Galloway's daughter, Sara, was born in January of 2000. Doctors diagnosed Sara with spinal muscular atrophy, a fatal form of muscular dystrophy that's genetically inherited.

"We knew things weren't right at all as soon as she was born," David said. "She couldn't move her arms or her legs. They immediately had to take her into neonatal ICU (Intensive Care Unit) to put her on a respirator. She couldn't breathe on her own."

David continued, "The prognosis was that we would never get her home. They made the recommendation that we take her off life support. She was three weeks old the day we did that."

Linda Galloway said, "Within a month or so of her death, we kept feeling like this can't be the end. It just felt like we needed another child, it just felt empty."

That's when the Galloways went searching for a technology that would enable the couple to pre-test for the disorder.

Linda and David turned to the Genetics and In Vitro Fertilization Institute in Fairfax, Va. to help them have another child. Scientists at the institute have developed many breakthrough genetic technologies -- including a way to create viable embryos free of inherited genetic diseases.

For more in from our "In Our Genes" Series: Gene Tests Rate Sudden Cardiac Death Risk

Dr. Harvey J. Stern, of the Genetics and In Vitro Fertilization Institute, explained, "We can track a segment of DNA from the inheritance through both parents to an embryo, and to be able to determine if that embryo is affected with one of a number of genetic disorders."

And for the Galloways, it was the answer to their prayers. They now have a daughter, Shannon, a healthy and strong 7-year-old.

Scientists at the institute are now working on a test that could detect 18,000 diseases prior to an embryo being implanted.

Stern said, "The utilization of this test can lead to a probably one and a half to two-fold increase in that success."

Could this lead to the creation of a perfect baby?

Stern said, "A perfect baby is an unrealistic concept. This is not genetic engineering. We are not changing the genes that parents will give to their child."

That's what the Galloways had always hoped for.

David said, "It's never totally filling the hole, but it sure lessens the pain. To be able to get that, 'Hi, Daddy. I love you.'"

Linda said, "I'm just thankful every day. She's our miracle."

Ashton added scientists at the Genetics and In Vitro Fertilization Institute hope they'll be able to offer this new screening tool that tests for thousands of diseases -- called 24 chromosome testing -- sometime in early 2010.

Ashton pointed out Linda Galloway gave birth to a healthy child before Sara.

"Early Show" co-anchor Maggie Rodriguez remarked that means even if you are a carrier, you don't necessarily pass along the disease, even if you pass along the gene.

Ashton added, "We have to remember that with all of these genetic advances, and these genetic types of tests, the results are not black or white. You might have a defect which puts you at risk for a disease or you might be a carrier. It doesn't necessarily mean that the disease will manifest itself in something serious."