Does a non-existiant human have rights?

I have recently been reading a book called “God and the Problem of Evil” I have enjoyed many of the arguments that have been presented by the various philosophers. I recently reviewed a work that made a certain analogy that caused me to become somewhat irritated. The analogy consisted of a man and women that desired to have a child, yet the child that they wanted was one the would be mentally retarded. So, in order to cause this outcome, they took some type of drug that causes sever damage to genetic material in sex cells of both males and females. Thus, when the child was born it was severely mentally handicapped…They (the parents) wanted this type of child to help it, in its obviously disadvantaged state, to achieve its full means of potential and happiness. The philosopher continues and says that the parents didn’t wrong the child because he didn’t have rights because it hadn’t existed…. So my question that I have currently been battling with is…Dose a child that is not brought into existence wronged by the incorrect choices of its parents? I assert that it is… I have not quite been able to come up with a sold argument proving that this is so. I think that you cold easily say that if a child is not given the best possible opportunity to exist then has been limited of said opportunity, if that is true then we have interfered with the opportunity of said child to achieve a maxim potential of progression. If that is true, then the parents who committed the initial limitation by their emotional desires have harmed the future progression of that child. If that is true then the right that the child had to live a full and complete life has been harmed.