Panzica in U.S. Pansica in Italy/Sicily?

[sfitz]

Hi there! I'm working on getting my dual citizenship. I've noticed that the Italian documents have my GGM's last name as Pansica but all the U.S. documents say Panzica. I did a search and it seems that Panzica is the typical spelling in Italy/Sicily so I'm curious why they might be spelling it with an s in those documents. Any idea? I'm not sure if this will be a hangup with the consulate or not. Thanks!