Study calls genetic tests into question

CHICAGO TRIBUNE

CHICAGO — Illustrating the complications of prenatal genetic testing, researchers reported Tuesday that some couples chose to terminate pregnancies even though the mutation carried by their fetus probably would not have resulted in serious health problems.

The researchers, from several medical centers in Israel, analyzed information about Gaucher disease, a genetic condition whose symptoms range from severe to nonexistent. It occurs mainly in Ashkenazi Jews, or those of Eastern or Central European descent.

Experts say the new findings, published in this week’s Journal of the American Medical Association, raise questions about the appropriateness of screening for treatable or nonlife-threatening diseases — a practice that is likely to increase as scientists continue to discover the function of individual genes.

Already, pregnant Ashkenazi women are usually screened for a battery of genetic diseases, including Tay Sachs, which invariably leads to extreme disability and early death. But the typical “Jewish panel” also includes some less serious conditions, such as Gaucher.

Expert committees in the U.S., Canada and Israel have all recommended against screening for Gaucher, yet the test continues to be offered routinely, doctors confirmed Tuesday.

Gaucher disease is caused by an enzyme deficiency that can lead to enlarged livers or spleens, anemia, bleeding and occasionally bone disease. In extremely rare cases it can result in progressive neurological problems.

Led by Shachar Zuckerman of Hebrew University-Hadassah Medical School in Jerusalem, the Israeli researchers searched records of genetic centers between 1995 and 2003 and found 82 “carrier couples” whose children risked being born with Type 1 Gaucher disease, the most common and mildest form.

Three-quarters of the couples had prenatal diagnosis performed when they got pregnant, and 16 affected fetuses were identified. Four of the 16 were aborted.

The researchers found that carrier couples were less likely to terminate their pregnancies if they were counseled by a specialist in Gaucher disease in addition to a genetic counselor.