Line breeding ?

Son- Mother cross.....

Wouldn't worry about defects unless the line has been inbred or heavily linebred for awhile.

Main thing to consider is the dogs to be crossed....

If you are wanting to reproduce common traits the two dogs you have...best way to give it a whirl.

But it also enhances the bad traits.

Better look at the so called skeletons in the dogs backgrounds ...including the male pups sire, but extremely close on the gyp..That's the one your gonna get a heavy shot of...good and bad.

Weigh the findings and Sling em....or Ring em.

Good luck