Soviet and a couple of other countries have this "glass-like" disease that makes one's entire body (bones and organs) behave like glass, though they are master regenerators, too many times breaking will leave them tired and vulnerable.
Other countries with this: Israel, Belarus, still coming up with things
Bonus:
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YonderBlue's Artbook/Short Stories
Short StoryThis is my (YonderBlue) art book, which has many things. Mostly Countryhumans... I also have small story ideas. Honestly, I got too much... So if any of you writers what to expand on one of my short stories you can ask and I'll see if I want to give...