My concern about this isn't the specific procedure, it is the moving of the line of what is allowed. What will happen next? I am sure there will be an illness where just a tiny bit of gene splicing could improve the lives of x amount of babies.

You look the blocking of websites.. It started with child porn which everyone thought was acceptable but then the same legislation was used against piracy websites. Now Britain has an internet filter...

Before there was a red line in genetics. Allowing this procedure really blurs that line and I worry this is just the start of a slippery slope..

As for how much it helps parents. It doesn't help many with their first child as the parents are often not aware they are carriers of conditions. For subsequent children adoption was always available.