Evidently there were "eunuchs" born back in Christ's time from their mother's womb. There were no jet fuel chemicals then, or other such chemicals that could cause genetically mutations back then, that we know of...
We know that Jesus raised the dead, turned water into wine, but there is no writing that he changed a male eunuch into a normal reproductive male.... just sayin....
So.... apparently this is something that happens as part of nature itself, and if you are born that way, apparently that is how God intended you to live, as a "eunuch" according to
Matthew 19:12. Here, Jesus was responding to the disciples question... "If the case of the man be so with his wife, then it is not good to marry." They were talking about the issue of adultery. And Jesus answered, all men cannot receive this saying (it is good not to marry), save they to whom it is given.
So it sounds here that Jesus is speaking of those who have received a commandment not to marry, especially in the case of the eunuchs. Perhaps these people who are born genderless.... were given the commandment not to marry?
I don't claim to have the answers at all... just trying to work through this issue myself ... having never thought it through or even realized it was an issue before this thread....