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“L.A. has a huge Persian Jewish community, so the need for that type of panel was great and we wanted to fill that hole,” said Catherine Quindipan, the genetic counselor in charge of the project.
From the results obtained by testing 1,000 people over two years, Cedars-Sinai was able to launch a Persian Jewish genetic panel in 2011, which enables prenatal screening for HIBM, pseudocholinesterase deficiency, polyglandular deficiency and congenital hydrocephalus — the four main genetic conditions prevalent among that population.
Similar panels are available in the New York area. In 2009, Dr. Martin Bialer of North Shore University Hospital in Long Island started developing a panel to screen for HIBM and Wolman disease, two conditions, he reasoned, that would have the most impact on couples thinking about starting a family.
“What we looked out for was, ‘What conditions does it make sense to screen for in a pregnant woman?’” he said.
Armed with their genetic status, carriers who want children have options. Randi Zinberg, a genetic counselor at Mount Sinai Hospital in New York, laid out three. A couple can choose to do nothing and take their chances — in the case of HIBM, the child will have a 1 in 4 chance of inheriting the condition if both parents are carriers. The second option is a prenatal diagnosis through chorionic villus sampling (done as early as 10 weeks), or amniocentesis (done from 15 weeks on). Early testing offers parents the options of terminating the pregnancy, or at the very least getting their options reviewed by a genetic counselor or physician. Finally, they can choose to use preimplantation genetic diagnosis, which tests the embryos for mutations prior to in-vitro fertilization, or gamete donation (sperm or egg).
Mount Sinai Hospital has developed a similar panel. But Ruth Kornreich, associate professor in genetics and genomic sciences, has broader plans. “We are currently working to expand our Jewish genetic disease panel, which would include both Ashkenazi and Sephardic Jewish mutations,” she explained, by which she meant mutations experienced by Jews from the Middle East.
But there is a special difficulty in developing an overarching panel for Jews from the Middle East. Unlike Ashkenazi Jews, who form a fairly unified transnational gene pool, Jews from the Middle East — Iranian Jews, Ethiopian Jews and Moroccan Jews, to name a few — each have their own discrete genetic diseases.
“For example, it might not make sense to screen for HIBM in a different [non-Iranian] subgroup,” Kornreich explained. This makes it harder to develop all-encompassing genetic tests similar to those tests now used for the Ashkenazi population.
Mount Sinai is currently determining the carrier frequencies for each disease, attributing them to relevant subgroups and validating the methodologies. The hospital hopes to have the expanded panel ready this year.
But the main barrier to screening remains the stigma that various populations of Jews from the Middle East attach to genetic disease.