Hairless mice?

Hey everyone,
For some reason one of my female mice has a weird brown spot or dark area on her back. I noticed it today. All of her babies also have lost almost all their hair. Here's some pics
Mom,
http://i972.photobucket.com/albums/a...8/80292e3f.jpg
http://i972.photobucket.com/albums/a...8/71255204.jpg
http://i972.photobucket.com/albums/a...8/2704b910.jpg
One of the babies.
http://i972.photobucket.com/albums/a...8/545edbc7.jpg
http://i972.photobucket.com/albums/a...8/6a265e07.jpg

I feed TSC brand dog food. They're all inbred. I have 12 other bins set up with 1.2 in each and this is the first and only time and litter I've experienced this. They are outside in a shed. All my mice are fed the same thing and all out of the same water supply.
Could it be through inbreeding I has discovered a hairless mouse gene lol? And they're bot severely inbred I think 1 or 2 generations.

Any help or hypothesis appreciated, Jeremy.

that last pix if it's the one looseing hair the skin looks a lil to red to be hairless i'd say it is some kind of disease reason being hairless mice don't start with hair then loose it they never grow any hair now if your mice never would of got hair in the first place then i'd say you found a hairless gene. what are your temps in there cages i'm sure mice are just like any other hair animal as in when it gets hotter they molt some of there hair to coop with the heat if they can't find someplace cooler. or it could be with the temps they aint growing hair in as quickly

there are hairless mice being bred

could be a skin disease...

could be from other mice attacking her....

could be genetic (balding).....

if only ONE mouse is doing it, I highly doubt it is environmental...

heres a bad pic of my het hairless and hairless, this might help

https://ball-pythons.net/gallery/fil...2/sdc10066.jpg