Clearly you don't mean what you say here.
Every magus obviously was a non-Hermetic child with the Gift once, many Gifted children even in central Europe never came to the attention of the Order, never met a magus interested in teaching them or proved untrainable, and ArM5 p.28, p. 75 and p. 166 provide basic rules for characters and NPCs with the Gift, but without Hermetic training.
And there certainly will be further rules for Gifted non-Hermetics in future supplements.
So what do you intend to say? 
Kind regards,
Berengar