- 1 in 4 Jews is a carrier for at least 1 of 19 preventable Jewish genetic diseases. If you and your partner are both carriers for the same genetic disease, there is a 25% chance with each pregnancy of having an affected child. Getting screened before becoming pregnant, and before every subsequent pregnancy, if testing for additional diseases becomes available, can prevent the possibility of having an affected child. Itâ€™s a no-brainerâ€¦ "Get screened for 19" yourself and help spread the word. Everyone of Jewish ancestry should get screened before becoming pregnant and update screening if testing for new diseases become available. All it takes is a simple blood test, which is the most comprehensive means of screening for all 19 diseases.