I have dyschondrosteosis and madelung wrist deformity. It is an extremely rare genetic disorder that runs in my family. We're actually being studied by a research team in Japan for it!
This is a genetic disorder which results in deformity of the bones. Extreme cases can cause dwarfism. I have a mild case, though it does result in very short stature (4'11"). Aside from height, the main thing it affects are your wrists. Basically, all of the bones in your wrist grow in wrong. There are different levels of severity. I have a more mild case. Even so, I had to wear braces on my wrist throughout high school, and during puberty, the pain in my forearms and wrists was constant and severe. It died down after puberty, and I just sort of learned to live with it. But my wrists are uncomfortable all the time. I just have trained myself not to think about it. Sometimes though, they do quite badly. My wrists move strangely too. I can fold my hand down so that my palm lies flat on my forearm, but I can't bend it backwards at all.
I have this condition, as does my sister, my mother, two aunts, and five cousins. My experience was painful enough, but as I said, I had pretty mild cases. My mother, an aunt, and a cousin all had severe cases. Though they too were not dwarves, only small statured like me, their wrists were severely deformed and they required many corrective surgeries in their childhood and teenage years.
This disease is almost always is a result of incest. I obviously don't know for certain if that was the case with my own family (I know for sure my grandparents aren't related, but that's as far back I can account for. We hardly know anything about our family since we came to the Unites States from Italy), but I do know that in MOST cases, if not my own, that is how the disease manifests.
Yes one could make the argument that a relationship which produces no offspring does no harm. But how would that be enforced, if incest were illegal? Would we force women who got pregnant from such a relationship to have abortions? That's what makes this whole thing tricky for me, is that how could we allow incest while enforcing that immediate family members do not reproduce, ESPECIALLY in multiple generations (so siblings continuously procreating with siblings)?
Of course there is the counter argument, that other things which can cause harm to a fetus/child are legal. It's not illegal to smoke while you're pregnant, after all, or eat nothing but junk food and malt liquor.
But still, incest can and does harm to people outside of those committing the act. It's just that there are other things which are harmful to a fetus which can result in lifelong medical complications, even things that have a HIGH risk of producing such complications, yet are legal.
