Do teacups grow up?

The Teacup is so named because the breed is the size of a teacup and can be placed inside a teacup, making it a playful breed. The Teacup itself has a genetic defect that results in its small size, but it has become rare and valuable because of this. As a result the Teacup cannot grow like other breeds and will always remain the same size. If the breed is not pure it will also grow up.