If 19 genes are not enough to worry about, there are now companies that have developed approaches to test hundreds of genes at once. Signature Genomics of PerkinElmer Corporation has a new approach to genetic testing that is called the PrenatalChipOS. The technology, which involves a device called a DNA chip or microarray, permits the mass screening of many genes at one time. According to its website, it is “the most comprehensive clinically-relevant oligonucleotide-based microarray for diagnostic use.” The array is able to evaluate “over 200 known genetic syndromes and over 500 gene regions of functional significance in human development.”
Another company, Counsyl, advertises the Universal Genetic Test, that can replace “100+ single gene tests.” The tests range from ABCC8-Related Hyperinsulinism (more common in people of Finnish and Saudi Arabian descent), to Wilson Disease (common in China, Japan and Sardinia), but also includes a number of genes found in higher incidence in Ashkenazi Jews.
The company explains its “values” as follows:
“We believe that genetic testing is a human right, not a luxury. We believe children deserve healthy lives, free from genetic disease. And we believe in universal access, especially for those most in need.”
The website (www.counsyl.com) discusses their mission, “to scale up the Jewish community’s successful campaign of universal carrier screening for Tay-Sachs, which vanquished the disease by 2003….To do this, we seek to both make preventive carrier testing universally accessible and to use our resources to find cures and treatments for families suffering from genetic disease.”
Counsyl representatives recently contacted Bergenfield obstetrician/gynecologist Dr. Efrat Meier-Ginsberg, who reports that the test costs $350 to evaluate many more genes, and test for many more diseases, at a lower cost than the conventional tests.
“On one hand, more information is better. But sometimes that’s not the case, especially when you ask, what are you going to do with the information?” said Meier-Ginsberg. “I’m very wary. I think people will get more nervous.”
When many genes are considered at once, the chance of finding a defective form of a gene rises sharply. She suggested that testing for hundreds of genes could cause people to unnecessarily terminate pregnancies, because not every mutation in a gene causes defects or serious disease. Nevertheless, added Meier-Ginsberg, “Patients should have the option to know what’s available to them and then it’s their decision.”
“Ain l’davar sof [there is no end to the matter],” said Dr. Steven Schuss, a Teaneck pediatrician, referring to the hundreds of genes tested in the new DNA array testing. “It’s a quality decision, and it could be a financial decision.”
“Some people want to know everything about everything, and some will say, ‘just tell me what to do,'” Schuss added. “I don’t feel this is a decision I can make for a patient. It comes down to the individual personality of the patient. Real pediatrics is not cookbook.”
Testing so many genes could also unnecessarily stigmatize people, as every person carries some mutations in some of their genes. In addition, suggested Rabbi Lawrence Zierler of the Jewish Center of Teaneck, if traits other than disease genes are tested, it could lead to designer babies, with parents picking and choosing traits of their offspring.
As it is, said Zierler, “people want such perfection.”
He described how some in the rigidly religious charedi community go to extremes to investigate potential partners. “My mother works in an optometrist’s office and gets phone calls asking, ‘Is so-and-so a patient in the practice?'” he said. In the search for a perfect mate, “they want to get information on what kind of eyes they have and what type of prescription they have….These [genetic tests] are shifting sands, and it can be taken to a dangerous place.”
Wayne resident Shari Ungerleider, an advocate for Jewish genetic testing, cautions that genetic tests, like the DNA arrays that rely only on DNA analysis of saliva samples, could be missing critical genetic mutations in the Tay-Sachs gene. “There are places that advertise DNA through saliva, but with Tay-Sachs it is recommended that you do enzyme testing, as well,” said Ungerleider, whose son died from Tay-Sachs. There are more than 50 variants of the Tay-Sachs gene that are known, thus DNA testing will identify only up to 95 percent of Ashkenazi Jews who are carriers, and 60 percent of carriers in the general population.
On the other hand, blood tests that measure the levels of the enzyme hexosaminidase A have close to 100 percent accuracy in detecting carriers. “I don’t support just saliva screening for Tay-Sachs. Blood testing is needed; make sure with Tay-Sachs to do enzyme and DNA testing,” Ungerleider said.
“I believe in educating people about all that is available out there, being screened, and screened the right way, and letting them make the decision that is best for them,” said Ungerleider. “If they know, they can make the decision that is best for them.”