dwarfism as a genetic defect

Question
I have a customer that says they used to breed mini rex rabbits and they supposedly had a defect that 1 in 4 babies born were dwarfed and didn't make it past a couple days old because they were so small.  I've had many different rabbits myself and bred them and have never heard of this.  Of course I may have missed it because I never bother my mother bunnies for about a week.  I just wanted to know if you had heard of this?

Answer
This is called double dwarfism, or peanuts, because Mini Rex were breed down from standard rex and netherland dwarfs, most mini rex have the dwarfing gene (this is what keeps them under 4 pounds) and when both parents contribute a dwarf gene to one baby you end up with a double dwarf or peanut.  This is fatal, and the babies generally don't live past about 10 days old, most breeders cull these at birth (they are physically deformed, which is what causes them to die, their digestive track can not process milk or food of any sort) or shortly their after.

It can happen in any breed that has the dwarf gene, but only if they get it from both parents. In my last two litters I had 2 peanuts in one (litter of 6) and none in the other(also litter of 6), so it is really a game of chance.

This is one of the reasons I advocate, handling the young or at least checking the nestbox everyday as a baby that dies in the box, can cause harm to the others in the litter by attracting flys and other pest/germs.

Also you can check out these websites for more info on peanuts
http://www.threelittleladiesrabbitry.com/peanuts.php
http://www.islandgems.net/peanuts.html
http://www.geocities.com/mnd_rabbitry/Peanut.html

Good luck
Amy