Could be the same mutation, or lack of mutation (depending on the original state of tolerance). However if there is no advantage/disadvantage at a certain point (such as our brains taking over to stop young suckling too long, or ample supply of other foods) then it would remain relatively rare in the gene pool.
Perhaps the opposite was true in Asia and your genes managed to survive where the tolerance was an disadvantage?
Does anyone know why some East Asians (such as myself) are lactose tolerant? Is that evidence of interbreeding in the past?