Igros Moshe (Even Haezer IV #10) Should a person take a test for Tay Sachs before marriage. Question Concerning the matter of the children who by nature live only a short time after being born, about two or three years and die, which is called Tay-Sachs.They are born from a father and mother who both contribute to produce this condition. Even though neither parent has the sickness or suffers any personal consequences for being a carrier for the sickness, the consequence is that they produce children with this sickness. If only one parent is a carrier than the children don’t get the sickness. It can be determined by a blood test whether the person is a carrier or not. This knowledge of who is a carrier can aid in deciding whether a particular boy should marry a particular girl. If he is a carrier he should avoid marrying a girl who is a carrier. She should avoid marrying a boy who is a carrier if she is a carrier. You want to know my humble opinion whether it is appropriate for the boy and girl to make an effort to find out whether they are a carrier If it is a good thing to take the test, should it be done while they are still children or only when they are ready for marriage? Should it be conducted in a public manner or privately? Answer Even though only a small small minority of children are born like this and it is appropriate to say about it, Tamimim Tehiye (be innocent with the L-rd your G-d), as Rashi explains that you should walk with G-d in innocence and wait for Him and do not inquire about the future. Nevertheless since it is now easy to test, perhaps not testing should be viewed as if he is closing his eyes to see what can be seen since if something like this happened to the child, it is extremely distressing to the parents. Consequently it would be appropriate to have this test prior to marriage. Therefore it is a good idea to publicize this in newspapersand other ways so that everyone knows there is such a test buy it is clear and obvious that this should be conducted privately so that the identities of the boy and girl should not be made public even by the doctor who does the test.
Rav Moshe is stating here that Tamim isn't violated by medical tests which easily determine information. However I was told that Rav Moshe was against medical screening tests such as pap tests when the person had no symptoms of illness. this includes yearly medical tests and x-rays as well as ptostate testing. In the eighth volume of the Igros they included the story that when he had a suspected heart attack he was upset they took a series of blood tests. So not sure what his actual view was.
