Mini Rex depend on the dwarfing gene to get the compact, "typey" animal described in the breed standard. Without the dwarfing gene, you get an animal that has a slightly longer head, longer ears, longer body, and weighs a bit more - maybe as much as a pound over the top weight in the standard. Because the dwarfing gene is a lethal gene, you can't breed true for it, and some kits won't inherit the dwarfing gene from either parent. If your Mini Rex has the dwarfing gene, the odds are 50/50 of him giving it to any particular kit he fathers, so yes, if he had kits with a standard sized doe, some of the kits should get the dwarfing gene. If he is an "oversized" Mini Rex without the dwarfing gene, none of the kits would get the gene.
Thank you.
I'm 75% sure this guy is a dwarf, he has that "little rabbit" look to him. I will get a pic to show you in a bit. I'm trying to find a girl bunny for him and I hope to find a female without the dwarf gene so to avoid any genetic misshaps. If I can't find a good one I'm tempted to try breeding him to one of my big does who I know carries for rex coat. I figure it can't be that different from breeding him to what mini breeders call a "BUD" Big ugly doe,