That is the end that I wanted to see in the manga. Thank you so much for your great work

Base +6, Bravelance +6, notfunnyguy +6

I would hope that they get over the fear and have children. Extra chance of genetic defect is around 3 percent in a world where it is legal for people with severe genetic defects to have children and then do dispite knowing chance of a major defect as high as 50%.
Now if both of them have a serious defect gene the chance of activation can even be worse maybe 75%.
But it totally illogical for adult siblings not to be able to marry and have children if other people with genetic defect are allowed to have children.

Base +6, Bravelance +6, notfunnyguy +6

@ Rocket 4000
Shouldn't neither have children? The rate of defects between first degree relatives (parent-child, siblings) is high, I'm not sure where you got the 'extra 3% chance' from. In a study where woman had both first degree incestuous and non-incestuous offspring, the rate of defects was 53% (42% severe) vs 7%.
First cousins is fine and dandy (+4%, less than older mothers), though repeated cousin marriage will raise the risk further through generations.

Base +6, Bravelance +6, kiwino -14