Before individuals undergo carrier testing in the events organized by the Jewish Genetic Diseases Center of Greater Phoenix, it is essential that they become familiar with certain basic information regarding Jewish genetic diseases and how they are inherited. Before blood is drawn for carrier testing, individuals will be required to have completed the brief quiz that follows the information presented on this page.
An opportunity will be available at the event to ask questions about Jewish genetic diseases and about the significance of a positive carrier test. Each participant will meet with a genetic counselor who will review the quiz to determine that the participant has sufficient understanding of the educational information to sign an Informed Consent and to proceed with carrier testing.
If you have any questions about this information or this requirement, please call 480-668-3347 or e-mail info@jewishgeneticsphx.org.
Certain genetic disorders occur with greater frequency in Jewish individuals of Eastern European origin than in the larger population. These diseases are therefore known as Jewish genetic diseases. It is important to recognize that they also occur in the larger population, but in a lesser frequency. 1 in 6 individuals of Jewish Eastern European (Ashkenazi) origin is a carrier for one of the Jewish genetic diseases.
Because the diseases occur only when each parent of an affected child is a carrier for that particular disorder, there is typically no family history of the disease in either the mother’s family or the father’s family. Carriers are healthy individuals who have no symptoms or signs of the disease for which they are carriers. The mutated gene that is responsible for the disease may pass from generation to generation and from carrier to carrier with no evidence of the disorder.
When two carriers for the same disorder become parents of children, there is a 50% likelihood with each pregnancy that the child will be a carrier (like each parent). There is a 25% likelihood with each pregnancy that the child will be affected by the disorder. There is a 25% likelihood that the child will be neither a carrier nor affected by the disorder.
When only one parent is a carrier, there remains a 50% likelihood with each pregnancy that the child will be a carrier (like the carrier parent). There is a 50% likelihood with each pregnancy that the child will be a non-carrier (like the non-carrier parent). If only one parent is a known carrier, an affected child will occur only when the second parent is also a carrier whose carrier testing failed to detect a disease mutation that was present. As indicated below, the detection rate for the carrier state for these disorders in the Ashkenazi Jewish community is very high, but it is not 100%. Genetic counseling to better understand the risks, therefore, is important when one parent is a known carrier.
If both parents are found to be carriers for the same disorder, it is very important that they seek genetic counseling to learn about options that are available to them to minimize the risk of having an affected child. Genetic counselors are trained to help such families make reproductive decisions that will increase the chances that their children will be healthy.
It is important to recognize that the Jewish genetic diseases are generally very serious disorders that may lead to childhood death in some instances and chronic debility and premature death in early adulthood in other instances. None are curable.
It is also important to know that with modern technology there is a very high detection rate for the carrier state for these disorders in the Ashkenazi Jewish community. The detection rate, however, is never 100%. When the same tests are done on individuals of other ethnic origins, the detection rate may be much lower. Genetic counseling is helpful to more fully understand the implication of both positive and negative carrier tests in different populations.
Genetic Carrier Testing Quiz
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