Yes, yes, even though she is a mix, test her monthly!
It is a simple test; all you do is get the urine glucose test strips. I use Diastix by Bayer, available at WalMart. Then catch a small amount of urine; with girl dogs I will just slide a clean paper bowl under them as they start to go or use a soup ladle, dip the test strip in the urine and see if it changes color within 30 seconds. No change, no worry. If it does change, have your vet run a full blood panel to check for glucose in the blood. If blood glucose is normal or below, the odds are your dog has Fanconi. If blood glucose is elevated, something else is going on; possibly diabetes or Cushing's.
There is no cure for Fanconi, but there is a treatment protocol which has been very effective in managing the syndrome. Many dogs with Fanconi live long active lives, even lure coursing and other sports with the protocol.
Every single Basenji line has Fanconi somewhere. Remember, we started with an extremely small gene pool. Possibly some of the new African imports could be Fanconi free, but virtually all of them were bred to American stock, so there's no guarantees.
Research is ongoing; and it is possible that there may be a Fanconi test within the next year or two. All of us that love this breed are thinking BIG positive hopes!
Terry