[Romulus]

Don't be obtuse. This isn't about consanguinity, which in any case is easily determined before marriage and whose determination does not require the murder of innocents.

To follow where your logic leads, we should have to believe either that Jews should not marry Jews, or else that Jews should murder Jews. Either way, it's Bad For The Jews.

[hrhdave]

Tay-Sachs screening is done before marriage. All Tay-Sachs trait carriers are descendants of a single 17th century Jewish ancestor. So in that respect, it is a matter of consanguinity.