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A hard choice After one child dies from genetic disease, a Johnstown couple seeks prenatal testing Sunday, July 02, 2000 By Byron Spice, Science Editor, Post-Gazette
Becca Rae Berkey would have been 2 years old this February. But she had a genetic disorder that never gave her a chance.
It was called infantile polycystic kidney disease. As she developed in her mother's womb, cysts caused her kidneys to balloon in size. By the time she was delivered prematurely at Conemaugh Health System in Johnstown, the overgrown kidneys had expanded into her chest. She was rushed to Magee-Womens Hospital, but her lungs were never able to inflate properly.
She died two days later.
None of the children of Darlene and Todd Berkey has had an easy time entering this world. Becca was Darlene's sixth pregnancy in 10 years, and only two of the children had survived.
Two were ectopic pregnancies that ended early -- pregnancies where the fetus forms outside the womb.
The other children were all premature. Darlene has two uteruses, a rare condition that makes it difficult for her to carry a child to term.
One child died when Darlene went into labor at 20 weeks' gestation. The surviving children, Todd, now 8, and Quinn, 5, did not have their sister's inherited kidney disorder, but had problems related to their premature births that required surgery or special care.
So when Darlene became pregnant again last year, she and Todd had some hard thinking to do. The chances were one in four this new child would also have infantile polycystic kidney disease, which almost always proves fatal. As much as they love children, neither one was prepared for the emotional upheaval of losing another child.
Would it be better just to end it?
"We did a lot of praying about it," she said. The couple, who live in rural Friedens in Somerset County, opted to have prenatal genetic testing at Magee.
Many people are uneasy about prenatal testing. The fear is that the tests deliver terrifying news to couples, who then have few options other than aborting the pregnancy.
But Dr. W. Allen Hogge, Berkey's doctor and the director of Magee's genetics department, said the reality isn't so ghastly. Rather than instigating abortions, prenatal testing may help reduce them, he argued.
Mostly good news
"I see it as reassurance," Hogge said. Prenatal tests usually provide good news for couples, which in turn encourages most couples to proceed with a pregnancy.
Even in the worst case, such as a dominant genetic disease like Huntington's that requires that a child inherit only a single "bad" gene from either parent, the odds of a good outcome for prenatal testing are 50-50.
More common are recessive genetic diseases, such as the infantile polycystic kidney disease that worried the Berkeys. In these cases, a child will get the disease only if he inherits a bad gene from each parent. Both Todd and Darlene are carriers for the kidney disease gene, which means they each have one good copy and one bad copy of the gene. Any child of theirs has a one-in-four chance of inheriting a bad copy of the gene from each parent.
But when you turn that around, Hogge said, that means that the chances that testing will bring good news are three out of four.
In any given week, 25 to 30 prenatal tests are performed at Magee. "Almost always," Hogge added, "we're going to give reassuring news."
Whether prenatal testing is considered comforting or disturbing, more couples will be undergoing the experience as genetic medicine expands in the next decade.
About half of all pregnancies already are screened for known chromosomal abnormalities, such as Down syndrome and spina bifida. About 5 percent of pregnant women undergo amniocentesis or chorionic villi sampling, which are procedures for removing cells for genetic analysis. These are routinely recommended for women over age 35.
In the United States, about 70 percent of couples are tested to determine if the parents are carriers for cystic fibrosis, a recessive disorder. Among Ashkenazi Jews, synagogues have led the way in testing for another recessive disorder, Tay-Sachs disease; virtually all Ashkenazi couples are now checked to see if they are carriers.
There also is required screening of newborns in Pennsylvania for genetic disorders such as phenylketonuria, congenital hypothyroidism, sickle cell disease and maple syrup urine disease, and many hospitals screen for dozens of other conditions.
Many of these tests will soon be performed before birth, Hogge predicted, because the mapping of the human genome and other work promise to vastly expand the number of prenatal tests and make it as cheap to test for a thousand diseases as for one.
And new genetic analysis technologies that require only a tiny number of cells, such as the method known as TAQman, may someday allow prenatal tests to be performed by using only a blood sample from the mother, which will make prenatal testing safer and noninvasive.
Effect on abortion
In some cases, an adverse finding may result in a decision to abort.
But more commonly, parents will learn that they need not worry about the health of their developing fetus, or will get an early warning that gives them extra time to prepare for a child with special problems or to have pediatric specialists available at the delivery to treat the child.
Consider the case of spinal muscular atrophy. Children born with this disease have poor muscle tone and die within six months of overwhelming disease. For many parents, the experience is so traumatizing that they choose not to try again.
"Five years ago, we had nothing to offer them," he said. Doctors could cite the odds of it happening again, but statistics offer little comfort for individuals. With the advent of prenatal DNA tests for this condition, however, more carriers of the gene defect are willing to attempt pregnancies.
Ronald Cole-Turner, a science ethicist at Pittsburgh Theological Seminary, said genetic technologies may also lead to treatments for diseases that are now difficult or impossible to remedy, and thus provide an alternative to abortion.
For instance, a dozen new therapies for cystic fibrosis, many related to insights gained from identifying the cystic fibrosis gene a decade ago, are now in the testing stages. "Do you terminate [a pregnancy] in an environment where medical science is moving so quickly?" Cole-Turner asked.
Another option that sidesteps any need for abortion is called single-cell analysis and allows genetic problems to be diagnosed before a fertilized egg is even implanted in the womb.
Embryos are created through in-vitro fertilization in the laboratory and are allowed to divide until each has eight cells. One cell is then carefully removed from each embryo and genetically analyzed. If any of the cells show a problem, those embryos are discarded. The remainder are transferred to the womb for implantation.
It's not an easy process, Hogge warned, and is available only in a handful of medical centers, none in the Pittsburgh area. It also carries all the expenses of normal in-vitro fertilization -- about $10,000 per cycle -- and has the same pregnancy success rate of 30 to 40 percent.
"It's going to be out of the [financial] range of the average couple," he said.
The Berkeys' decision
The Berkeys didn't have to rely on anything so exotic.
Last summer, Darlene Berkey underwent chorionic villi sampling, or CVS, which involves removing a tiny piece of the placenta from inside the womb. Like amniocentesis, which obtains cells for genetic analysis from the amniotic fluid, CVS carries a 1-in-200 risk of miscarriage. But CVS can be performed very early in a pregnancy, between 10 and 12 weeks, which gives parents more time to consider their options.
CVS also was advisable because Darlene was over 35, another risk factor for genetic abnormalities.
She knew that if the test results were bad, there wouldn't be much hope.
No prenatal treatment is available for polycystic kidney disease, and most children, like Becca Rae, die within a day or two of birth because their lungs can't inflate.
If the child can survive long enough, a kidney transplant can be performed. And while prenatal testing might help parents and doctors prepare for such a transplant, Hogge noted survival would remain a long shot.
Darlene Berkey's CVS was performed in the 10th week of her pregnancy. The sample was sent to an Alabama lab for analysis and the Berkeys went home to wait the three or four weeks necessary for the results.
The tests showed that the baby had inherited one copy of the gene.
It meant he would be a carrier of the genetic disorder, but would not develop the disease.
On Dec. 27, during the 33rd week of pregnancy, Darlene went into labor. Many friends and relatives had wondered why, after so much heartbreak, she and Todd would attempt to have another child. It was hard to explain, she admitted, but after 36 hours of labor, the answer emerged.
His name is Brady.
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