I have mutated fingers, because I am right-handed I used my right hand a lot whilst I was young and the fingers kinda 'grew' straight of their own violition. The shape of my left-hand is very annoying though and the fingers obstruct eachother, causing that hand to be pretty useless. =p
At any rate, as far as I am aware right-handed-ness prevails throughout the world (in numbers). I dunno if there's any connection between country of origin and what hand you prefer (though perhaps in countries where people are poorer and forced to do more with their hands they might become left-handed more easily? dunno) so your observation might just be false-cause correlation.
Ah well... ^_^