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Fetal Testing Study Sparks Concern

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By KAREN KAPLAN, Los Angeles Times

Published: September 19, 2007

Thirty-five years after genetic screening was 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 and the rest can lead normal lives with treatment.

Researchers found that among couples who met with a Gaucher expert and learned that the disease is treatable, 8 percent 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 in the Journal of the American Medical Association, 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.

William 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 probably will 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?'

The proliferation of screening tests was driven largely by the success of carrier screening for Tay-Sachs disease, a condition with high incidence among Ashkenazi Jews.

Children with Tay-Sachs are unable to process a fatty substance that builds up in the body and leads to blindness, deafness, paralysis and death by age 4. Since screening for Tay-Sachs began in the early 1970s, the number of cases has dropped by 90 percent.

Other diseases for which Ashkenazi Jews frequently are screened include Canavan disease and Niemann-Pick disease, which lead to death in early childhood, and debilitating conditions such as cystic fibrosis.

Ephrat Levy-Lahad, director of the Medical Genetics Unit at Shaare Zedek Medical Center in Jerusalem, and colleagues wondered how screening for a relatively mild condition such as Gaucher affected couples' family planning decisions.

Gaucher disease is the most common genetic disease among Jews of Eastern European descent. Scientists estimate that 6 percent to 10 percent of Ashkenazi Jews are carriers of at least one mutation that can lead to the disorder. Roughly 60 percent of eligible couples in Israel take the Gaucher screening test, Levy-Lahad said.
Gaucher patients can experience pain and suffer from fatigue, although the symptoms can be treated with biweekly infusions of the enzyme that their bodies fail to produce in sufficient quantities.

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