It could be genetic, but I doubt it, as this happens alot more so than you may think with geckos. It has alot to do with the placement of the developing gecko within the egg (my opinion). I have a male P.picta that was born with a deformed tail. It doesn't affect breeding, and will most likely never show up in babies produced by her. Possible it could if the babies were inbred back to her though, but that isn't adviseable by me or most others.lol. Good luck!
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Leland
"Captive Bred Geckos from Around the World"
www.dwgeckos.com