Thirty-five years after genetic screening was first used to identify babies at risk of being born with debilitating diseases, a new study of a potentially serious but treatable illness among Ashkenazi Jews questions whether such testing has gone too far.
One-quarter of fetuses found to have Gaucher disease were aborted over an eight-year period, even though half of all children with the metabolic disorder will never experience any symptoms, such as pain, organ enlargement and anemia. The rest can lead normal lives with treatment.
Importantly, the researchers found that among couples who met with a Gaucher expert and learned that the disease was treatable, only 8% chose to terminate their pregnancies. All of the couples who didn't have those meetings opted for abortion.
The disparity underscores what some experts say is a flaw in genetic testing: It provides a bounty of knowledge that is not necessarily accompanied by wisdom.
The study, published today in the Journal of the American Medical Assn., tracked nearly 29,000 Israelis who opted to be screened for mutations in their DNA that could lead to Gaucher disease in their children if they inherit faulty genes from both parents.
Similar screening tests are offered to other specific ethnic groups predisposed to disorders, such as albinism and congenital deafness.
Dr. William R. Wilcox, who treats Gaucher patients at the Medical Genetics Institute at Cedars-Sinai Medical Center in Los Angeles and was not involved in the study, said that given the ambiguity inherent in some genetic tests, they should not be given for diseases that are imminently treatable.
"Personally, that horrifies me," he said. "Why is it there? Because we can do it. But just because we can doesn't mean we should."
Others say abandoning the genetic test would unfairly deny couples genetic information about their offspring.
"It's an opportunity to gain information which some people might want," said Karen Grinzaid, a genetic counselor at Emory University in Atlanta who coordinates care for Gaucher patients. "It's their decision about what they want to do with that information."
As gene-hunters find more DNA mutations associated with particular diseases, the number of people who will be left grappling with ambiguous results is likely to grow, experts said.
"This is just the tip of the iceberg," Wilcox said. "There will be a time when we have the ability to screen for thousands of diseases in one blood spot. What are you going to terminate for?"
