Yes you can. Line breeding is common with reptiles and does not cause the same kinds of issues you see in mammals. I wouldn't do it for multiple generations, but line breeding is how many of the morphs we have today were proven out.
Thomas "Slim" Whitman
Never Met A Ball Python I Didn't Like
If you do a thread title search on the keyword inbreeding (from the Advanced Search page), you'll find a couple of interesting threads that are certainly worth reading through.
Thomas "Slim" Whitman
Never Met A Ball Python I Didn't Like
I cannot speak about the effect on snakes but with dogs line breeding is common. Inbreeding is not.
The most common form of line breeding is father to daughter. Mother to son is less common. Brother to sister is considered inbreeding and has been known to produce undesireable results and is not worth the risk in dogs. Reptiles?