[Wavytone]

There are many congenital defects that deserve to be patched in this way. Patching defects IMHO is entirely rational where it can be shown doing this will produce a better quality of life than the alternatives - or doing nothing.

Starting with various visual defects (I have three, one major two minor), muscular dystrophy, heart defects, and many more. Then there are the tragic ones like Down's syndrome. Many of these wreck the lives of the parents as well as the child.

While in some cases the adults who carry the defective gene these days are encouraged to have children (such as heart defects) on the basis that it can be remedied physiologically (eg surgery), the trouble is the defective gene is still passed on and allowed to spread in the population - whereas if nature was allowed to prevail children with these defects would not reach reproduction.

Hence the real challenge for modern medicine is to stop these defective genes being passed on to successive generations in the first place.

When our son was born I was very worried he would inherit the visual defects I have but thankfully his vision is like his mothers. A 50/50 gamble.