Genetic Screening Urged for Ashkenazi Jews
Miryam Z. Wahrman, Ph.D.
"Many believe, in error, that Tay-Sachs has been conquered," declared Marion Yanovsky, Co- President of the National Tay-Sachs & Allied Diseases Association (NTSADA), New York Area Chapter. Yanovsky spoke at the L'Dor V'Dor, From Generation to Generation, Health Education Conference held recently in the YM-YWHA of Wayne, New Jersey.
Shari Ungerleider, a member of the Hadassah Women's Health Committee, who attended the conference, can verify that Tay-Sachs is still very real and poses a potential threat to couples where one or both members are Ashkenazi Jews. "The doctor tested me [for Tay Sachs] and misread the test and told me I wasn't a carrier," recalled Shari Ungerleider. "After Evan was diagnosed with the disease, I was retested and my husband was tested and we were both carriers."
Babies with Tay-Sachs disease appear normal for the first few months of life, then begin to deteriorate, losing mental and physical abilities. As the disease progresses, the child becomes blind, deaf, unable to swallow, and eventually paralyzed, usually dying by age 3-5.
Evan Ungerleider died of Tay-Sachs disease last year, at the age of four. His parents, Shari and Jeff Ungerleider, have honored his memory by establishing the Evan Lee Ungerleider Foundation of NTSADA. According to a NTSADA brochure, "The foundation's goal is to raise money for research, education, carrier testing, and family support services. It is hoped that these efforts will help prevent the tragedy of Tay-Sachs and allied genetic diseases in other families."
"Since1970 we've tested for carriers of Tay-Sachs," reported Yanovsky, "And due to that we've been able to reduce the number of births of Tay-Sachs children in the Ashkenazi Jewish community by approximately 90%."
However, one drawback noted by Yanovsky is that due to the success of the screening program, "many rabbis, doctors and people in general think that the disease has been cured, or doesn't exist anymore. And people often do not think to test."
"If you don't test for your carrier status, the only other way to find out if your a carrier is to, God forbid, have a child with the disease," Yanovsky cautioned. "Therefore we have to constantly pursue the path of carrier testing, because there is no cure [now] and [any future cure] is quite a distance away."
"Recently there was a young couple in Rockland County with a Tay-Sachs child," Yanovsky continued. "Their rabbi never told them to be tested. And they had relatives who were tested who never told them [to be tested]."
Since rabbis commonly counsel couples before a marriage is performed, The NTSADA has established a program, in cooperation with the New York Board of Rabbis, designed to educate rabbis with regard to genetic testing. The NTSADA offers educational materials for rabbis to distribute to couples who are about to be married.
"Unfortunately, we have not received enough support [from the rabbis]. In two mailings we have received only a 5% response," reported Yanovsky, referring to the fact that in a recent mailings only about 30 out of 600 rabbis responded. Rabbis respond by requesting "Gift of Life" cards to distribute to couples, reminding them to have a Tay-Sachs test. "The [few] rabbis who responded told us how many cards they wanted," said Yanovsky, "but then we never heard from them again."
According to Zinberg, in the Ashkenazi Jewish population, there's a 1 in 25 carrier frequency for Tay-Sachs disease, 1 in 40 for Canavan disease and 1 in 70 for Niemann-Pick Disease. All three of these diseases are lethal within the first few years of life.
There are a total of seven serious diseases, including the three invariably fatal ones listed above, that can be tested for in the Ashkenazi Jewish community. Others which are screened for include: Type 1 Gaucher disease, Cystic Fibrosis, Fanconi Anemia and Bloom syndrome. In the next year or so, an eighth disease, Familial Dysautonomia, is expected to be added to this panel of tests.
"Of couples that screen for all seven diseases," reported Zinberg, "one in six individuals will be carriers for one of those diseases." In order for an affected baby to be conceived, both parents must have copies of the same disease gene. Then, if they both do carry the same disease gene, there is a one in four risk of conceiving a child with that particular disease.
"We ask couples to be screened so we know if a couple is at risk. If we only screen one member and find a positive, then there's tremendous anxiety until the partner is screened." Zinberg explained. "Many come when they're already pregnant, so every week is precious and they need to know as soon as possible."
"If both are carriers, they have options: They can decide not to have children, or they can have children but monitor the pregnancies," said Zinberg.
The types of monitoring which are available include chorionic villus sampling (CVS) which is done at 10-12 weeks, amniocentesis, done at 15 weeks of pregnancy, and the less common preimplantation diagnosis which can only be done in conjuction with in vitro fertilization (IVF). Preimplantation diagnosis involves microsurgery on the embryo a few days after it is conceived in a petri dish in the IVF laboratory. One cell from each embryo is removed and genetically tested for specific genetic disorders. Then, only the embryos which are found to be unaffected with those disorders are implanted into the mother's uterus.
A new technique which addresses the needs of ultra-orthodox Jews is a variation on the conventional CVS technique. "Early CVS has been done among the ultrareligious as an avenue for termination," explained Zinberg. The idea behind this new development is to teminate the pregnancy within 40 days post-conception, since destroying an embryo which is less than 40 days old is not considered by halacha [Jewish law] to be a destruction of human life. "If CVS is done at 7 weeks [from the last menstrual period - presumably 5 weeks after conception] you can get the results back before 40 days."
However, admitted Zinberg, "It is technically more difficult and there is more risk involved. The numbers [of these cases] are still small so we can't give the percent risk to the pregnancy,"
Ungerleider recalled her experiences with testing. When she was first tested, before Evan was born, "the results were ambiguous - the doctor was not able to correctly interpret the results." "So," cautioned Ungerleider, "be sure to go to a genetics center, like Mount Sinai [for testing]."
After Evan was born, and before conceiving their second child, the Ungerleiders went for a whole battery of tests. The tests confirmed that they were both carriers of Tay-Sachs, but were negative for the other diseases. When Ungerleider became pregnant for the second time, she had a CVS test, which indicated that the baby was unaffected, and that child, Justin, is now three years old.
Their third preganancy, screened at 10 weeks by CVS, was found to be positive for Tay Sachs disease, and was terminated. However, now Ungerleider is visibly pregnant again, and is due in November. This baby, a girl, she is happy to report, is not afflicted with Tay-Sachs.
"I suggest that people go to be tested, if possible, prior to being pregnant, so they are aware of their carrier status and can make an educated decision," Ungerleider advised. "That way they can have prenatal testing done at an early point in the pregnancy."
"Be in charge of your own health," she continued. "Some doctors don't realize that even in a marriage of an Ashkenazi Jew to a non-Jew, there still is a real risk."
Zinberg reported that it costs approximately $500 per couple to be screened for the seven diseases at Mount Sinai. And commercial companies can charge much more for these tests.
"But a child with the disease costs the community thousands and thousands each year," reminded Yanovsky.
Other speakers at the conference included Janice Greenwald, Hadassah National Chair, who gave an update on the Hadassah Medical Organization, Joyce Gartenberg of the New Jersey Alzheimer's Association who spoke about the impact of Alzheimer's Disease on the family and Ruth Ann Denchy of Mount Sinai who spoke about breast cancer genes.
The conference was sponsored by Hadassah Young Women/Young Leaders, the New York Area Chapter of the National Tay-Sachs & Allied Diseases Association (NTSADA), and the Susan G. Komen Breast Cancer Foundation. Information about NTSADA can be obtained by calling (212) 431-0431.