You caught it really early. So your animal shouldn't develope the serious problems associated with MBD like bone fractures. The one thing we don't know is how long an animal has to be exposed to bad husbandry for it to develope MBD later in life.
Our MBD gecko Twinkie was purchased at an expo and he weighed around 4g at the time and showed no signs at all. Once he hit around 10g it started becoming apparent. Once we realized what it was though we just bumped up his CGD feedings and toss him some calcium caked bugs every now and then. We seem to have slowed the progression of it.
So basically, he will be just fine but he will be somewhat of a special needs animal. I wouldn't recommend breeding him just because we do not know if there is a genetic component or not. The vet probably won't be able to tell you much at this stage, your animal has not started to break down bone to supply calcium to his blood so an X-ray likely won't show anything. Like I said though, just toss a 2.0 or 5.0 UVB Exo Terra UVB bulb on top of his cage and purchase some kind of electrical timer for it to cut on for 2-4 hours a day and then cut off.