Question: If there is a case of a Tay Sachs baby, is it permissible to have an abortion, especially when both parents of the child agree the baby must be aborted?

Answer: Any real question – meaning, someone is really considering this – must be handled by a competent rabbi in person, not via this forum.

That said, in principle, it is not permissible to kill an unborn child just because he has a disease, any more than it is permissible to kill him after he is born.

There may be exceptions to this rule, that must be handled on a case-by-case basis.

Rabbi Seinfeld