User blog comment:Zori9/Strawhats Crew Member's Family:/@comment-4681125-20120315050553/@comment-3075024-20120315115254

 "Franky's real name is Cutty Flam (カティ・フラム, Kati Furamu). He was born in the South Blue. When he was young his parents (who were pirates) threw him off their ship into the ocean. He was then rescued by the legendary shipwright Tom, who made Cutty Flam his apprentice after seeing Cutty Flam make a cannon out of scrap that was lying about."

I hope this was little helpful. Franky was from south blue and it seems his parents threw him away .. scumbags >_> throwing away such great talent TT^TT