Maxpowernap

Hey there. I’ve held the pen weird ever since I was a kid, and a few years ago I noticed that I’m missing a joint in my thumb. Both thumbs, actually. It’s the basal joint. There’s no pain or anything, perfectly functional (except people text faster than me), and my sister has it, too. I’ve searched the internet but can’t really find anything conclusive. Any ideas? thanks in advance! cheers, max