Could be. Just have a look at the centres. Regardless as to whether your cube is genuine or not, there should be 4 edge pieces for each centre colour. The colours opposite each other won't have a shared edge piece.
Eg. on my cube as with most, white is opposite yellow, so I get white-red, white-blue, white-green and white-orange, but not white-yellow.
If your cube has each pair, it should be solvable (unless someone put a corner in wrong after taking it apart, but you could just pop the cube apart and reassemble it to fix that).
If your cube is indeed made up of parts from several, but it still works, all is not lost.
You can purchase spare sticker sets from here and other sites, or you could spray your cube