Screening for genetic disorders has come a long way since the first tests for Tay-Sachs disease in the late 1960s. At the time, clinicians screened the Jewish community by measuring enzyme levels in people’s blood. But in the late 1980s, newer genetic tests became available for Tay-Sachs and, soon after, for a range of other so-called “Jewish genetic diseases” including Canavan disease, cystic fibrosis and Fanconi anemia.
The DNA-based tests were more specific, allowing for more reliable diagnoses of whether people harbored rare recessive mutations. But the tests were also more expensive: Testing for each disease generally cost between $100 and $500, depending on the number of mutations inspected.
As the number of diseases included in community screens grew, so did the price tag for testing. And with more than a dozen diseases now routinely tested, commercial labs often charge thousands of dollars for the whole lot, and insurance companies vary on the degree of reimbursement.
New technologies, however, are bringing down the sticker price of genetic disease screening. Unlike older approaches — which were often laborious and time-consuming, requiring lab technicians to test for individual mutations one by one, in piecemeal fashion — most laboratory work is now automated, with many different genetic tests conducted in parallel on a single “gene chip.” As such, screening for the full panel of Ashkenazi Jewish disease can now cost as little as a single DNA test for Tay-Sachs did 20 years ago.
Already, several academic laboratories, including those at the Jacobi and Mount Sinai medical centers, have implemented the chip-based technologies in Jewish community screens around the New York area (although they continue to use enzyme-based assays in tandem with newer DNA methods to screen specifically for Tay-Sachs).
One of the first commercial companies to market the cheaper DNA approach is Counsyl, a startup based in California’s Silicon Valley. The preventive carrier-screening company now provides testing for 18 Ashkenazi Jewish diseases at $349, and plans to add Walker-Warburg syndrome to its panel later this summer.
However, gene chip methods may soon be supplanted by the latest DNA sequencing technologies. According to Counsyl’s president, Balaji Srinivasan, the company soon plans to offer full DNA readouts for nearly 100 diseases, including a dozen that are particularly common among Ashkenazi Jews. Counsyl has not yet priced the test, but Srinivasan said it will cost about as much as the current Jewish panel.
At that point, deciding what test to use will pose more of an epistemic than a financial dilemma, experts say. “Next-generation sequencing shows mutations that are less strongly correlated with disease,” said Dr. Susan Gross, director of the Program for Jewish Genetic Health at Yeshiva University. “So people have to ask themselves how much they want to know.”
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