My husband is Jaquez, his parents are from the Dominican Republic. I am a linguist, and as far as I've reserched, Jaquez is the Haitian Creole spelling of the French last name Jacques. The creole simplifies the french, thereby losing the "c" and changing the "-ez" (ay) ending to an -s sound. Dominicans (and apparently Mexicans) pronounce it /há-kes/, haitians pronounce it like the french Jacques, but with a final "-s" sound /zhaks/.