[comrade_ogilvy]

Your points are all good ones.

The likely problem is the potential for increased suffering for future generations, not necessarily to the child to be immediately born.

There are genes that a usually superior when heterogenous. Sickle cell is the classic example. But it is quite possibly true that Tay-Sachs is also heterogeneous superior -- there is circumstantial evidence that it has been positively selected for.

If people feel it is necessary to make the smartest children possible, the grandchildren will risk immense unnecessary suffering, unless they are brought into this world under the loving care of a genetic counselor.