It depends on many factors. Just as in a rifle the sights are above the bore. The bore is very slightly angled upward when the front and rear sights are aligned.
The bullet will always start out below the sights and at some range the point of impact will be exactly where the point of aim is. The bullet will continue up until it reaches its apex and will drop down and will cross the line of sight a 2nd time.
Most handguns are zeroed where the bullet crosses the line of sight the first time, while on the way up. Most rifles are zeroed where it crosses the 2nd time, when on the way down.
I'd say that with MOST handguns, if the bullet is low at 12 yards, it will be even lower at 25, but it is almost impossible to say. If the bullet has not reached it's apex before 12 yards, then it will still be on its way up at that range and could be zeroed at 25 or even hitting a little high.
The barrel length, the height of the sights above the bore and the individual load are all determining factors. The only way to know for sure it to shoot at those ranges.
A snub nose 38 with fixed sights very close to the bore will be much different than a 44 magnum with adjustable sights mounted higher above a 6-8" barrel. Heavy bullets impact higher than lighter bullets because greater recoil causes the muzzle to rise more during recoil before the bullet leaves the barrel.