Jumpholes are artificially created, semi-stable, wormholes that can collapse, and when so doing, naturally reform at new locations shortly thereafter.
Jumpgates are artificially created, semi-stable, static wormholes. They are tied to the gate, and can be turned on and off at will, but cannot move, or collapse. Jumpgate structures are the only methods known by humans of how to create a "jumphole."
There are no naturally occuring wormholes in Sirius... Yet.