To me, most of this is a non-issue. I am willing to believe that autism is genetic, but neither of my parents are, nor any other relative anywhere, no matter how far out or back I can go. I'm it!
Two NT parents and, bam, an AS child. So there is no guarantee that anyone will or will not have an autistic child anyway. So, I am willing to accept the on/off gene theory, but there is no way it is hereditary in same way as haemophilia.
So.... I go back to my original post. It is a matter of whether someone on the spectrum can be a good parent. If you can, then breed away.
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"If you can't call someone else an idiot, then you are obviously not very good at what you do."