Jewish Genetic Disorders: What Your Congregants Should Know

2,732 views

Published on

A primer for rabbis from the Chicago Center for Jewish Genetic Disorders and Children's Memorial Hospital

Published in: Health & Medicine, Technology
  • Be the first to comment

  • Be the first to like this

Jewish Genetic Disorders: What Your Congregants Should Know

  1. 1. What Your Congregants Should Know Chicago Center for Jewish Genetic Disorders & Children’s Memorial Hospital Jewish Genetic Disorders:
  2. 2. <ul><li>In general, 1 in 3-5 Ashkenazi Jews is a carrier for at least one of these disorders </li></ul><ul><li>Some disorders are more common than others- carrier frequencies range from 1 in 15 to 1 in 149 </li></ul><ul><li>Ways in which the disorders differ </li></ul><ul><ul><li>Age of onset – many have early childhood onset </li></ul></ul><ul><ul><li>Degrees of severity – many are lethal </li></ul></ul><ul><ul><li>Treatment options – very few have effective treatment </li></ul></ul><ul><li>Genetic testing is now available for almost all the disorders listed later </li></ul>Ashkenazi Jewish genetic disorders represent a varied group of conditions
  3. 3. Genetics <ul><li>A gene… </li></ul><ul><li>Is made of DNA, the basic genetic material </li></ul><ul><li>Carries the chemical instructions to make all the proteins in the body </li></ul><ul><li>Has the instruction or “code” for one particular protein </li></ul><ul><li>We have two copies of most genes </li></ul>
  4. 4. What is a genetic mutation and how does it lead to disease? <ul><li>A change in the DNA of a particular gene can result in an alteration of the genetic instructions. </li></ul><ul><li>Some genetic alterations are not harmful but are part of our genetic differences (for example, hair color and eye color). </li></ul><ul><li>An alteration in a gene can lead to disease by affecting the function of that gene. </li></ul>
  5. 5. Many of the Ashkenazi Jewish genetic disorders are inherited in a recessive fashion When both parents are carriers for the same disorder, they have a 25% chance in each pregnancy of having an affected child.
  6. 6. Facts about carriers of recessive genetic disorders <ul><li>Every individual is estimated to be a carrier of 6-8 genes which can produce disease. </li></ul><ul><li>Carriers are generally not affected because they have a fully functioning copy of the disease gene. </li></ul><ul><li>Only when both copies of the gene are not functioning will an individual be affected with the disease. </li></ul><ul><li>Most carriers will have no family history of that genetic disorder. </li></ul>
  7. 7. Ethnicity <ul><li>Certain ethnic groups have a higher risk for certain genetic conditions than the general population. </li></ul><ul><ul><li>Northern European Caucasians: cystic fibrosis </li></ul></ul><ul><ul><li>African Americans: sickle cell disease </li></ul></ul><ul><ul><li>Mediterranean ancestry:  -thalassemia </li></ul></ul>& Disease Judaism is not only a religion and culture, but also a distinct ethnicity.
  8. 8. Why does ethnicity determine disease risk? Founder Effect <ul><li>A few individuals migrated and founded a new, isolated population. </li></ul><ul><li>Within this group there was a founder who carried a genetic mutation. </li></ul><ul><li>The group was then, by chance, different from the population that the settlers came from. </li></ul>
  9. 9. For what diseases are Sephardic Jews at increased risk? <ul><li>Beta-thalassemia </li></ul><ul><li>Familial Mediterranean fever </li></ul><ul><li>Glycogen storage disease, type III </li></ul><ul><li>G6PD deficiency </li></ul>
  10. 10. What disorders are Ashkenazi Jews at increased risk for? <ul><li>Bloom’s syndrome </li></ul><ul><li>Canavan disease </li></ul><ul><li>Cystic fibrosis </li></ul><ul><li>Familial dysautonomia </li></ul><ul><li>Fanconi anemia, group C </li></ul><ul><li>Gaucher disease, type I </li></ul><ul><li>Mucolipidosis IV </li></ul><ul><li>Niemann-Pick disease, type A </li></ul><ul><li>Tay-Sachs disease </li></ul><ul><li>Dihydrolipoamide dehydrogenase deficiency </li></ul><ul><li>Familial hyperinsulinism </li></ul><ul><li>Glycogen storage disorder, type 1a </li></ul><ul><li>Joubert syndrome </li></ul><ul><li>Maple syrup urine disease </li></ul><ul><li>Nemaline myopathy </li></ul><ul><li>Spinal muscular atrophy </li></ul><ul><li>Usher syndrome type 1F </li></ul><ul><li>Usher syndrome type 3 </li></ul><ul><li>Hereditary breast and ovarian cancer syndrome (Dominant inheritance) </li></ul><ul><li>Torsion dystonia (Dominant inheritance) </li></ul>
  11. 11. *Important note about the disorders <ul><li>There is no set panel of Ashkenazi Jewish genetic disorders. Different labs screen for different panels of these disorders. Diseases listed in italics are explicitly recommended by American College of Medical Genetics (ACMG). The others on the right fit ACMG criteria except the last four. Please see the Chicago Center website, www.jewishgenetics.org, for more detailed information about the disorders. </li></ul>
  12. 12. To whom should screening be offered? <ul><li>Carrier screening is available for disorders more common in the Ashkenazi Jewish population by looking for specific mutations that are most common in this group. </li></ul><ul><li>Individuals with at least one Ashkenazi Jewish grandparent, or suspected Ashkenazi ancestry, should be offered screening. </li></ul><ul><li>Screening should still be offered to a Jewish individual even if his/her partner is not biologically Jewish, as none of these disorders are exclusive to the Jewish population. </li></ul>
  13. 13. What options are available to couples found to be at risk? <ul><li>Sperm or egg donation </li></ul><ul><li>Preimplantation genetic diagnosis </li></ul><ul><li>Prenatal diagnosis by amniocentesis or chorionic villus sampling </li></ul><ul><li>Adoption </li></ul><ul><li>Choosing to accept the risk </li></ul>
  14. 14. How successful is carrier screening? <ul><li>The Tay-Sachs Model </li></ul><ul><li>One of the most successful screening programs for genetic disease </li></ul><ul><li>Strong participation from the Jewish community </li></ul><ul><li>Involvement of religious leaders </li></ul><ul><li>Programs have been able to nearly eliminate Tay-Sachs disease from the Jewish population </li></ul>
  15. 15. Incidence of Classical Tay-Sachs disease in the U.S. and Canada
  16. 16. A decrease in the number of affected individuals DOES NOT mean a decrease in carrier frequency.
  17. 17. Why would someone choose not to be screened? <ul><li>Lack of awareness about Tay-Sachs and other Ashkenazi Jewish diseases </li></ul><ul><li>Some people assume that there is no need to be tested if: </li></ul><ul><ul><li>Parents were screened for Tay-Sachs— but we now screen for many more disorders. </li></ul></ul><ul><ul><li>Marrying someone who is not Jewish— but testing is still recommended for the Jewish partner. </li></ul></ul><ul><li>Cost—Many insurance plans do not cover carrier testing. </li></ul><ul><li>Fear of stigmatization/effect on relationships </li></ul>
  18. 18. Dor Yeshorim <ul><li>A confidential genetic screening system used mainly by Orthodox Jews for the purpose of preventing the transmission of Jewish genetic disorders </li></ul><ul><li>Participants do not receive their results, only their genetic compatibility with a potential marital partner. </li></ul><ul><li>Dor Yeshorim screens for a panel of Ashkenazi Jewish genetic disorders for approximately $200. If an individual has previously used this system, updates are available through the Dor Yeshorim Program. </li></ul><ul><li>Dor Yeshorim will not screen already engaged or married couples. </li></ul>
  19. 19. For more information about carrier screening or to find a local genetic counselor, please visit www.jewishgenetics.org The Center is a cooperative effort of Jewish United Fund/Jewish Federation of Metropolitan Chicago and Children’s Memorial Hospital and is funded in part by the Michael Reese Health Trust.

×