Thanks kaliope. Regarding the probability, we have an autosomal dominant disorder, which has 50% chance to pass to offspring. The 25% chance is for autosomal recessive disorders. Yes, I do understand that disability don't make anyone less accepted in our current society. But one of us still oppose to take that chance because the consequences of that chance going wrong will affect our kids more than how it affect us. There is a difference between taking that chance knowingly and unknowingly. And one of us strongly believes that even if it spoils his/her own life, one should not knowingly put a still not born human-being in a difficult state.